old research studies

When is the evidence too old?

A few weeks ago, when submitting an abstract to a nursing conference, I was suddenly faced with a dilemma about age. Not my own age, but the age of evidence I was using to support my work. One key element of the submission criteria was to provide five research citations to support the abstract, and all citations were to be less than ten years old.  This requirement left me stumped for a while. The research I wanted to cite was more than ten years old, yet it was excellent research within a very small body of work on the topic. Suddenly I struggled to meet the criteria and almost gave up on the submission, thinking my abstract would not tick all of the boxes if I used research now deemed to be ‘out of date’. I suddenly thought about all of the work I had published more than ten years ago – all that hard work past its use-by date.

Way back in the mid 1990s, a colleague and I started to have conversations with Australian nurses about the importance of evidence based practice (EBP) for the future of Australian nursing.  The movement away from the comfort of ‘ritual and routine’ to the uncertainty of EBP was challenging. At the time we described EBP according to the principle that “all interventions should be based on the best currently available scientific evidence” 1 . We had embraced the ideas of authors such as Ian Chalmers 2 and were keen to educate nurses and nursing students about “practices that had been clearly shown to work and question practices for which no evidence exists and discard those which have been shown to do harm” 1 It was very much about the importance of using the most ‘robust’ and ‘reliable’ evidence that we had available to guide us in clinical decision making, taking into account individual patients at the centre of care. It was also about teaching nurses and nursing students about how to ask the right questions, where to look for answers and how to recognize when you have found the right answer to support individualized patient care.

Definitions of evidence-based practice are quite varied and I have heard nurses talk about using “current best evidence” while others use the “most current evidence”. These are quite different approaches, with the latter statement suggesting that more recent is best. This is sometimes reinforced in nursing education, where students are graded according to the use of recent research, with limitations placed on the age of resources used to support their work. However, I wonder if we are losing something in this translation about the meaning of ‘best evidence’ to support care. When does the published evidence get too old and where do we draw the line and stop reading research from our past?

Personally I have always expected my students to use up to date research when supporting their recommendations for care. However, I have also encouraged them to look back to see where the new research has come from and to acknowledge the foundation it has been built on.  I am always keen to hear about the latest developments in healthcare and work to support the readers of EBN who need and want to know about what is new and important in the health care literature. Keeping up to date with new evidence is critically important for change. But I wonder how we strike a balance between absorbing recent research and taking into account robust research that preceded its publication by more than a decade?

So, let’s think about these ideas for a minute. If we put our blinkers on and ignore important research from the recently ‘outdated’ literature from the 1990s (when I first became interested in doing research), we could miss some important foundational work that still influences practice today. The two references I have used below, both from the 1990s, would not be included in the discussion at all. If we only consider literature that is recent, and value that more highly than if it is robust, then we will be missing important evidence to inform practice. Researchers could start asking the same research questions over and over (I have seen some of this already in nursing literature) and even feel pressured to repeat previous studies all over again to check if the findings still hold true in the contemporary world. Perhaps that is something to watch for in the future.

It is important to keep up to date with current research findings, new innovations in care, recent trends in patient problems, trends in patient outcomes and changes in the social, political and system context of the care we provide. But it is also important to look back as we move forward, thinking about the strength of the evidence as well as its age.

Allison Shorten RN RM PhD

Yale University School of Nursing

References:

• Shorten A. & Wallace MC. ‘Evidence-based practice – The future is clear’. Australian Nurses Journal, 1996, Vol. 4, No. 6, pp. 22-24.
• Chalmers I. The Cochrane collaboration: Preparing, maintaining, and disseminating systematic reviews of the effects of health care, Annals New York Academy of Science, 1993, Vol. 703, pp. 156-165.

Comment and Opinion | Open Debate

The views and opinions expressed on this site are solely those of the original authors. They do not necessarily represent the views of BMJ and should not be used to replace medical advice. Please see our full website terms and conditions .

All BMJ blog posts are posted under a CC-BY-NC licence

BMJ Journals

The Vast Majority of Raw Data From Old Scientific Studies May Now Be Missing

A new survey of 20-year-old studies shows that poor archives and inaccessible authors make 90 percent of raw data impossible to find

Joseph Stromberg

One of the foundations of the scientific method is the reproducibility of results. In a lab anywhere around the world, a researcher should be able to study the same subject as another scientist and reproduce the same data, or analyze the same data and notice the same patterns.

This is why the findings of a study published today in  Current Biology  are so concerning. When a group of researchers tried to email the authors of 516 biological studies published between 1991 and 2011 and ask for the raw data, they were dismayed to find that more 90 percent of the oldest data (from papers written more than 20 years ago) were inaccessible. In total, even including papers published as recently as 2011, they were only able to track down the data for 23 percent.

"Everybody kind of knows that if you ask a researcher for data from old studies, they'll hem and haw, because they don't know where it is," says  Timothy Vines , a zoologist at the University of British Columbia, who led the effort. "But there really hadn't ever been systematic estimates of how quickly the data held by authors actually disappears."

To make their estimate, his group chose a type of data that's been relatively consistent over time—anatomical measurements of plants and animals—and dug up between 25 and 40 papers for each odd year during the period that used this sort of data, to see if they could hunt down the raw numbers.

A surprising amount of their inquiries were halted at the very first step: for 25 percent of the studies, active email addresses couldn't be found, with defunct addresses listed on the paper itself and web searches not turning up any current ones. For another 38 percent of studies, their queries led to no response. Another 7 percent of the data sets were lost or inaccessible.

"Some of the time, for instance, it was saved on three-and-a-half inch floppy disks, so no one could access it, because they no longer had the proper drives," Vines says. Because the basic idea of keeping data is so that it can be used by others in future research, this sort of obsolescence essentially renders the data useless.

These might seem like mundane obstacles, but scientists are just like the rest of us—they change email addresses, they get new computers with different drives, they lose their file backups—so these trends reflect serious, systemic problems in science.

And preserving data is so important, it's worth remembering, because it's impossible to predict in which directions research will move in the future. Vines, for instance, has been conducting his own research on a pair of toad species native to Eastern Europe that seem to be in the process of hybridizing. In the 1980s, he says, a separate team of researchers was working on the same topic, and came across an old paper that documented the distribution of these toads in the 1930s. Knowing that their distribution had changed relatively little over the intervening decades allowed the scientists to make all sorts of calculations that wouldn't have been possible otherwise. "That original data being available, from a very small old study written in Polish, was incredibly useful to researchers that came along 70 years later," he says.

There's also the fact that so much of this research is paid for with public funding, much of it coming through grants that stipulate that resulting data be made freely available to the public. Additionally, field data is affected by the circumstances of the environment in which it's collected—thus, it's impossible to perfectly replicate later on, when conditions have changed.

What's the solution? Some journals—including  Molecular Ecology , of which Vines is a managing editor—have adopted policies that require authors to submit raw data along with their papers, allowing the journal itself to archive the data in perpetuity. Although journals, like people, are susceptible to changing email addresses and technological obsolescence, these problems can be much more easily managed at the institutional scale.

Get the latest Science stories in your inbox.

Joseph Stromberg | | READ MORE

Joseph Stromberg was previously a digital reporter for Smithsonian .

• Department of Health and Human Services
• National Institutes of Health

COVID-19 Research Studies

More information, about clinical center, clinical trials and you, participate in a study, referring a patient.

About Clinical Research

Research participants are partners in discovery at the NIH Clinical Center, the largest research hospital in America. Clinical research is medical research involving people The Clinical Center provides hope through pioneering clinical research to improve human health. We rapidly translate scientific observations and laboratory discoveries into new ways to diagnose, treat and prevent disease. More than 500,000 people from around the world have participated in clinical research since the hospital opened in 1953. We do not charge patients for participation and treatment in clinical studies at NIH. In certain emergency circumstances, you may qualify for help with travel and other expenses Read more , to see if clinical studies are for you.

Medical Information Disclaimer

Emailed inquires/requests.

Email sent to the National Institutes of Health Clinical Center may be forwarded to appropriate NIH or outside experts for response. We do not collect your name and e-mail address for any purpose other than to respond to your query. Nevertheless, email is not necessarily secure against interception. This statement applies to NIH Clinical Center Studies website. For additional inquiries regarding studies at the National Institutes of Health, please call the Office of Patient Recruitment at 1-800-411-1222

Find NIH Clinical Center Trials

The National Institutes of Health (NIH) Clinical Center Search the Studies site is a registry of publicly supported clinical studies conducted mostly in Bethesda, MD.

• Bipolar Disorder
• Therapy Center
• When To See a Therapist
• Types of Therapy
• Best Online Therapy
• Best Couples Therapy
• Managing Stress
• Sleep and Dreaming
• Understanding Emotions
• Self-Improvement
• Healthy Relationships
• Student Resources
• Personality Types
• Sweepstakes
• Guided Meditations
• Verywell Mind Insights
• 2024 Verywell Mind 25
• Mental Health in the Classroom
• Editorial Process
• Meet Our Review Board
• Crisis Support

Classic Psychology Experiments

The history of psychology is filled with fascinating studies and classic psychology experiments that helped change the way we think about ourselves and human behavior. Sometimes the results of these experiments were so surprising they challenged conventional wisdom about the human mind and actions. In other cases, these experiments were also quite controversial.

Some of the most famous examples include Milgram's obedience experiment and Zimbardo's prison experiment. Explore some of these classic psychology experiments to learn more about some of the best-known research in psychology history.

Harlow’s Rhesus Monkey Experiments

In a series of controversial experiments conducted in the late 1950s and early 1960s, psychologist Harry Harlow demonstrated the powerful effects of love on normal development. By showing the devastating effects of deprivation on young rhesus monkeys , Harlow revealed the importance of love for healthy childhood development.

His experiments were often unethical and shockingly cruel, yet they uncovered fundamental truths that have heavily influenced our understanding of child development.

In one famous version of the experiments, infant monkeys were separated from their mothers immediately after birth and placed in an environment where they had access to either a wire monkey "mother" or a version of the faux-mother covered in a soft-terry cloth. While the wire mother provided food, the cloth mother provided only softness and comfort.

Harlow found that while the infant monkeys would go to the wire mother for food, they vastly preferred the company of the soft and comforting cloth mother. The study demonstrated that maternal bonds   were about much more than simply providing nourishment and that comfort and security played a major role in the formation of attachments .

Pavlov’s Classical Conditioning Experiments

The concept of classical conditioning is studied by every entry-level psychology student, so it may be surprising to learn that the man who first noted this phenomenon was not a psychologist at all. Pavlov was actually studying the digestive systems of dogs when he noticed that his subjects began to salivate whenever they saw his lab assistant.

What he soon discovered through his experiments was that certain responses (drooling) could be conditioned by associating a previously neutral stimulus (metronome or buzzer) with a stimulus that naturally and automatically triggers a response (food). Pavlov's experiments with dogs established classical conditioning.

The Asch Conformity Experiments

Researchers have long been interested in the degree to which people follow or rebel against social norms. During the 1950s, psychologist Solomon Asch conducted a series of experiments designed to demonstrate the powers of conformity in groups.  

The study revealed that people are surprisingly susceptible to going along with the group, even when they know the group is wrong.​ In Asch's studies, students were told that they were taking a vision test and were asked to identify which of three lines was the same length as a target line.

When asked alone, the students were highly accurate in their assessments. In other trials, confederate participants intentionally picked the incorrect line. As a result, many of the real participants gave the same answer as the other students, demonstrating how conformity could be both a powerful and subtle influence on human behavior.

Skinner's Operant Conditioning Experiments

Skinner studied how behavior can be reinforced to be repeated or weakened to be extinguished. He designed the Skinner Box where an animal, often a rodent, would be given a food pellet or an electric shock. A rat would learn that pressing a level delivered a food pellet. Or the rat would learn to press the lever in order to halt electric shocks.

Then, the animal may learn to associate a light or sound with being able to get the reward or halt negative stimuli by pressing the lever. Furthermore, he studied whether continuous, fixed ratio, fixed interval , variable ratio, and variable interval reinforcement led to faster response or learning.

Milgram’s Obedience Experiments

In Milgram's experiment , participants were asked to deliver electrical shocks to a "learner" whenever an incorrect answer was given. In reality, the learner was actually a confederate in the experiment who pretended to be shocked. The purpose of the experiment was to determine how far people were willing to go in order to obey the commands of an authority figure.

Milgram  found that 65% of participants were willing to deliver the maximum level of shocks   despite the fact that the learner seemed to be in serious distress or even unconscious.

Why This Experiment Is Notable

Milgram's experiment is one of the most controversial in psychology history. Many participants experienced considerable distress as a result of their participation and in many cases were never debriefed after the conclusion of the experiment. The experiment played a role in the development of ethical guidelines for the use of human participants in psychology experiments.

The Stanford Prison Experiment

Philip Zimbardo's famous experiment cast regular students in the roles of prisoners and prison guards. While the study was originally slated to last 2 weeks, it had to be halted after just 6 days because the guards became abusive and the prisoners began to show signs of extreme stress and anxiety.

Zimbardo's famous study was referred to after the abuses in Abu Ghraib came to light. Many experts believe that such group behaviors are heavily influenced by the power of the situation and the behavioral expectations placed on people cast in different roles.

It is worth noting criticisms of Zimbardo's experiment, however. While the general recollection of the experiment is that the guards became excessively abusive on their own as a natural response to their role, the reality is that they were explicitly instructed to mistreat the prisoners, potentially detracting from the conclusions of the study.

Van rosmalen L, Van der veer R, Van der horst FCP. The nature of love: Harlow, Bowlby and Bettelheim on affectionless mothers. Hist Psychiatry. 2020. doi:10.1177/0957154X19898997

Gantt WH . Ivan Pavlov . Encyclopaedia Brittanica .

Jeon, HL. The environmental factor within the Solomon Asch Line Test . International Journal of Social Science and Humanity. 2014;4(4):264-268. doi:10.7763/IJSSH.2014.V4.360 

Koren M. B.F. Skinner: The man who taught pigeons to play ping-pong and rats to pull levers . Smithsonian Magazine .

B.F. Skinner Foundation. A brief survey of operant behavior .

Gonzalez-franco M, Slater M, Birney ME, Swapp D, Haslam SA, Reicher SD. Participant concerns for the Learner in a Virtual Reality replication of the Milgram obedience study. PLoS ONE. 2018;13(12):e0209704. doi:10.1371/journal.pone.0209704

Zimbardo PG. Philip G. Zimbardo on his career and the Stanford Prison Experiment's 40th anniversary. Interview by Scott Drury, Scott A. Hutchens, Duane E. Shuttlesworth, and Carole L. White. Hist Psychol. 2012;15(2):161-170. doi:10.1037/a0025884

Le texier T. Debunking the Stanford Prison Experiment. Am Psychol. 2019;74(7):823-839. doi:10.1037/amp0000401

Perry G. Deception and illusion in Milgram's accounts of the Obedience Experiments . Theoretical & Applied Ethics . 2013;2(2):79-92.

Specter M. Drool: How Everyone Gets Pavlov Wrong . The New Yorker. 2014; November 24.

By Kendra Cherry, MSEd Kendra Cherry, MS, is a psychosocial rehabilitation specialist, psychology educator, and author of the "Everything Psychology Book."

An official website of the United States government

Here's how you know

The .gov means it’s official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

What Are Clinical Trials and Studies?

On this page:

What is clinical research?

Why participate in a clinical trial, what happens in a clinical trial or study, what happens when a clinical trial or study ends, what are the different phases of clinical trials, questions to ask before participating in clinical research, how do researchers decide who will participate, clinical research needs participants with diverse backgrounds.

By participating in clinical research, you can help scientists develop new medications and other strategies to treat and prevent disease. Many effective treatments that are used today, such as chemotherapy, cholesterol-lowering drugs, vaccines, and cognitive-behavioral therapy, would not exist without research participants. Whether you’re healthy or have a medical condition, people of all ages and backgrounds can participate in clinical trials. This article can help you learn more about clinical research, why people choose to participate, and how to get involved in a study.

Mr. Jackson's story

Mr. Jackson is 73 years old and was just diagnosed with Alzheimer’s disease . He is worried about how it will affect his daily life. Will he forget to take his medicine? Will he forget his favorite memories, like the births of his children or hiking the Appalachian Trail? When Mr. Jackson talked to his doctor about his concerns, she told him about a clinical trial that is testing a possible new Alzheimer’s treatment. But Mr. Jackson has concerns about clinical trials. He does not want to feel like a lab rat or take the chance of getting a treatment that may not work or could make him feel worse. The doctor explained that there are both risks and benefits to being part of a clinical trial, and she talked with Mr. Jackson about research studies — what they are, how they work, and why they need volunteers. This information helped Mr. Jackson feel better about clinical trials. He plans to learn more about how to participate.

Clinical research is the study of health and illness in people. There are two main types of clinical research: observational studies and clinical trials.

Observational studies monitor people in normal settings. Researchers gather information from people and compare changes over time. For example, researchers may ask a group of older adults about their exercise habits and provide monthly memory tests for a year to learn how physical activity is associated with cognitive health . Observational studies do not test a medical intervention, such as a drug or device, but may help identify new treatments or prevention strategies to test in clinical trials.

Clinical trials are research studies that test a medical, surgical, or behavioral intervention in people. These trials are the primary way that researchers determine if a new form of treatment or prevention, such as a new drug, diet, or medical device (for example, a pacemaker), is safe and effective in people. Often, a clinical trial is designed to learn if a new treatment is more effective or has less harmful side effects than existing treatments.

Other aims of clinical research include:

• Testing ways to diagnose a disease early, sometimes before there are symptoms
• Finding approaches to prevent a health problem, including in people who are healthy but at increased risk of developing a disease
• Improving quality of life for people living with a life-threatening disease or chronic health problem
• Studying the role of caregivers or support groups

Learn more about clinical research from MedlinePlus and ClinicalTrials.gov .

People volunteer for clinical trials and studies for a variety of reasons, including:

• They want to contribute to discovering health information that may help others in the future.
• Participating in research helps them feel like they are playing a more active role in their health.
• The treatments they have tried for their health problem did not work or there is no treatment for their health problem.

Whatever the motivation, when you choose to participate in a clinical trial, you become a partner in scientific discovery. Participating in research can help future generations lead healthier lives. Major medical breakthroughs could not happen without the generosity of clinical trial participants — young and old, healthy, or diagnosed with a disease.

Where can I find a clinical trial?

Looking for clinical trials related to aging and age-related health conditions? Talk to your health care provider and use online resources to:

• Search for a clinical trial
• Look for clinical trials on Alzheimer's, other dementias, and caregiving
• Find a registry for a particular diagnosis or condition
• Explore clinical trials and studies supported by NIA

After you find one or more studies that you are interested in, the next step is for you or your doctor to contact the study research staff and ask questions. You can usually find contact information in the description of the study.

Let your health care provider know if you are thinking about joining a clinical trial. Your provider may want to talk to the research team to make sure the study is safe for you and to help coordinate your care.

Joining a clinical trial is a personal decision with potential benefits and some risks. Learn what happens in a clinical trial and how participant safety is protected . Read and listen to testimonials from people who decided to participate in research.

Here’s what typically happens in a clinical trial or study:

• Research staff explain the trial or study in detail, answer your questions, and gather more information about you.
• Once you agree to participate, you sign an informed consent form indicating your understanding about what to expect as a participant and the various outcomes that could occur.
• You are screened to make sure you qualify for the trial or study.
• If accepted into the trial, you schedule a first visit, which is called the “baseline” visit. The researchers conduct cognitive and/or physical tests during this visit.
• For some trials testing an intervention, you are assigned by chance (randomly) to a treatment group or a control group . The treatment group will get the intervention being tested, and the control group will not.
• You follow the trial procedures and report any issues or concerns to researchers.
• You may visit the research site at regularly scheduled times for new cognitive, physical, or other evaluations and discussions with staff. During these visits, the research team collects data and monitors your safety and well-being.
• You continue to see your regular physician(s) for usual health care throughout the study.

How do researchers decide which interventions are safe to test in people?

Before a clinical trial is designed and launched, scientists perform laboratory tests and often conduct studies in animals to test a potential intervention’s safety and effectiveness. If these studies show favorable results, the U.S. Food and Drug Administration (FDA) approves the intervention to be tested in humans. Learn more about how the safety of clinical trial participants is protected.

Once a clinical trial or study ends, the researchers analyze the data to determine what the findings mean and to plan the next steps. As a participant, you should be provided information before the study starts about how long it will last, whether you will continue receiving the treatment after the trial ends (if applicable), and how the results of the research will be shared. If you have specific questions about what will happen when the trial or study ends, ask the research coordinator or staff.

Clinical trials of drugs and medical devices advance through several phases to test safety, determine effectiveness, and identify any side effects. The FDA typically requires Phase 1, 2, and 3 trials to be conducted to determine if the drug or device can be approved for further use. If researchers find the intervention to be safe and effective after the first three phases, the FDA approves it for clinical use and continues to monitor its effects.

Each phase has a different purpose:

• A Phase 1 trial tests an experimental drug or device on a small group of people (around 20 to 80) to judge its safety, including any side effects, and to test the amount (dosage).
• A Phase 2 trial includes more people (around 100 to 300) to help determine whether a drug is effective. This phase aims to obtain preliminary data on whether the drug or device works in people who have a certain disease or condition. These trials also continue to examine safety, including short-term side effects.
• A Phase 3 trial gathers additional information from several hundred to a few thousand people about safety and effectiveness, studying different populations and different dosages, and comparing the intervention with other drugs or treatment approaches. If the FDA agrees that the trial results support the intervention’s use for a particular health condition, it will approve the experimental drug or device.
• A Phase 4 trial takes place after the FDA approves the drug or device. The treatment’s effectiveness and safety are monitored in large, diverse populations. Sometimes, side effects may not become clear until more people have used the drug or device over a longer period of time.

Clinical trials that test a behavior change, rather than a drug or medical device, advance through similar steps, but behavioral interventions are not regulated by the FDA. Learn more about clinical trials , including the types of trials and the four phases.

Choosing to participate in research is an important personal decision. If you are considering joining a trial or study, get answers to your questions and know your options before you decide. Here are questions you might ask the research team when thinking about participating.

• What is this study trying to find out?
• What treatment or tests will I have? Will they hurt? Will you provide me with the test or lab results?
• What are the chances I will be in the experimental group or the control group?
• If the study tests a treatment, what are the possible risks, side effects, and benefits compared with my current treatment?
• How long will the clinical trial last?
• Where will the study take place? Will I need to stay in the hospital?
• Will you provide a way for me to get to the study site if I need it, such as through a ride-share service?
• Will I need a trial or study partner (for example, a family member or friend who knows me well) to come with me to the research site visits? If so, how long will he or she need to participate?
• Can I participate in any part of the trial with my regular doctor or at a clinic closer to my home?
• How will the study affect my everyday life?
• What steps are being taken to ensure my privacy?
• How will you protect my health while I participate?
• What happens if my health problem gets worse during the trial or study?
• Can I take my regular medicines while participating?
• Who will be in charge of my care while I am in the trial or study? Will I be able to see my own doctors?
• How will you keep my doctor informed about my participation?
• If I withdraw from the trial or study, will this affect my normal care?
• Will it cost me anything to be in the trial or study? If so, will I be reimbursed for expenses, such as travel, parking, lodging, or meals?
• Will my insurance pay for costs not covered by the research, or must I pay out of pocket? If I don’t have insurance, am I still eligible to participate?
• Will my trial or study partner be compensated for his or her time?
• Will you follow up on my health after the end of the trial or study?
• Will I continue receiving the treatment after the trial or study ends?
• Will you tell me the results of the research?
• Whom do I contact if I have questions after the trial or study ends?

To be eligible to participate, you may need to have certain characteristics, called inclusion criteria. For example, a clinical trial may need participants to have a certain stage of disease, version of a gene, or family history. Some trials require that participants have a study partner who can accompany them to clinic visits.

Participants with certain characteristics may not be allowed to participate in some trials. These characteristics are called exclusion criteria. They include factors such as specific health conditions or medications that could interfere with the treatment being tested.

Many volunteers must be screened to find enough people who are eligible for a trial or study. Generally, you can participate in only one clinical trial at a time, although this is not necessarily the case for observational studies. Different trials have different criteria, so being excluded from one trial does not necessarily mean you will be excluded from another.

When research only includes people with similar backgrounds, the findings may not apply to or benefit a broader population. The results of clinical trials and studies with diverse participants may apply to more people. That’s why research benefits from having participants of different ages, sexes, races, and ethnicities.

Researchers need older adults to participate in clinical research so that scientists can learn more about how new drugs, tests, and other interventions will work for them. Many older adults have health needs that are different from those of younger people. For example, as people age, their bodies may react differently to certain drugs. Older adults may need different dosages of a drug to have the intended result. Also, some drugs may have different side effects in older people than in younger individuals. Having older adults enrolled in clinical trials and studies helps researchers get the information they need to develop the right treatments for this age group.

Researchers know that it may be challenging for some older adults to join a clinical trial or study. For example, if you have multiple health problems, can you participate in research that is looking at only one condition? If you are frail or have a disability, will you be strong enough to participate? If you no longer drive, how can you get to the research site? Talk to the research coordinator or staff about your concerns. The research team may have already thought about some of the potential obstacles and have a plan to make it easier for you to participate.

Read more about diversity in clinical trials .

You may also be interested in

• Learning more about the benefits, risks, and safety of clinical research
• Finding out about participating in Alzheimer's disease research
• Downloading or sharing an infographic with the benefits of participating in clinical research

Sign up for email updates on healthy aging

For more information about clinical trials.

Alzheimers.gov www.alzheimers.gov Explore the Alzheimers.gov website for information and resources on Alzheimer’s and related dementias from across the federal government.

Clinical Research Trials and You National Institutes of Health www.nih.gov/health-information/nih-clinical-research-trials-you

ClinicalTrials.gov www.clinicaltrials.gov 

This content is provided by the NIH National Institute on Aging (NIA). NIA scientists and other experts review this content to ensure it is accurate and up to date.

Content reviewed: March 22, 2023

nia.nih.gov

An official website of the National Institutes of Health

• Publications
• Newsletters
• In the News
• Participant Appreciation
• Join the Study
• About Brain Donation

Co-Principal Investigators:  Claudia Kawas, MD ;  Maria Corrada, ScD Co-Investigators:  Annlia Paganini-Hill, PhD ; Dana Greenia, RN, MS

The 90+ Study  was initiated in 2003 to study the oldest-old, the fastest growing age group in the United States.   The   90+ Study  is one of the largest studies of the oldest-old in the world. More than 1,600 people have enrolled.  Because little is known about people who achieve this milestone, the remarkable increase in the number of oldest-old presents a public health priority to promote the quality as well as the quantity of life.

The 90+ Study participants

Initial participants in  The   90+ Study  were once members of The Leisure World Cohort Study (LWCS), which was started in 1981.  The LWCS mailed surveys to every resident of Leisure World, a large retirement community in Orange County, California (now incorporated as the city of Laguna Woods).  Using the 14,000 subjects from the LWCS, researchers from  The   90+ Study  were able to ask,  What allows people to live to age 90 and beyond?

Studying the oldest-old

Participants of  The 90+ Study  are visited every six months by researchers who perform neurological and neuropsychological tests. Our researchers at the Clinic for Aging Research and Education (CARE), located in Laguna Woods, obtain information about diet, activities, medical history, medications and numerous other factors. Additionally, participants are given a series of cognitive and physical tests to determine how well people in this age group are functioning.

Goals of the study

• Determine factors associated with longevity:   What makes people live to age 90 and beyond?  What types of food, activities or lifestyles are associated with living longer?
• Examine the epidemiology of dementia in the oldest-old:  How many people aged 90 and older have dementia?  How many become demented each year?  What are ways to remain dementia-free into your 90s?
• Examine rates of cognitive and functional decline in the oldest-old:  How do memory loss and disability affect those in their 90s?  How can people prevent memory loss and disability at this age?
• Examine clinical pathological correlations in the oldest-old:   Do the brains of people in their 90s show evidence of memory loss and dementia?  Do people with dementia have differences in their brains that can be detected and treated?  Determining Modifiable Risk Factors for Mortality and Dementia: What kinds of things can people change in their lives to live longer?  Can people change their risk of dementia through diet, exercise or supplements?

Major findings

Researchers from  The 90+ Study  have published many scientific papers in premier journals.  Some of the major findings are:

• People who drank moderate amounts of alcohol or coffee lived longer than those who abstained.
• People who were overweight in their 70s lived longer than normal or underweight people did.
• Over 40% of people aged 90 and older suffer from dementia while almost 80% are disabled. Both are more common in women than men.
• About half of people with dementia over age 90 do not have sufficient neuropathology in their brain to explain their cognitive loss.
• People aged 90 and older with an APOE2 gene are less likely to have clinical Alzheimer’s dementia, but are much more likely to have Alzheimer’s neuropathology in their brains.

The 90+ Study  is seeking new participants. If you are at least 90 years old and are willing to participate in twice annual visits and donate your brain to research after death, you may be eligible to enroll in  The 90+ Study .

Please contact 949.768.3635 or  [email protected]  for more information.

The 90+ Study Team

Co-Principal Investigators

Claudia Kawas, MD

Maria Corrada, ScD

Co-Investigators

Dana Greenia, RN, MS

S. Ahmad Sajjadi, MD, PhD

Neurological Examiners

Farah Mozaffar, MD

Neuropsychological Testers

Colette Aguirre, MPH, BA

Jaime Demoss, BA

Christina Whittle, BS

Study Coordination/Administration

Montez Hester, BS

Maria Kirkwood

Data Management/Statistical Analysis

Natalie Bryant, BS

Blinda Li, MS

Students/Volunteers

Jude Tahrawi

Neuropathologic burden and dementia in nonagenarians and centenarians. Cholerton BA, Latimer CS, Crane PK, Corrada MM, Gibbons LE, Larson EB, Kawas CH, Keene CD, Montine TJ. Neurology. 2024 Feb 13;102(3):e208060. [Online 2024 Jan 4]. PMID: 38175995. 

LATE and potential estrogen-related risk factors collected 30 years earlier: The 90+ Study. Paganini-Hill A, Montine TJ, Bukhari SA, Corrada MM, Kawas CH, Sajjadi SA. J. Neuropathol Exp Neurol. 2023 Jan 20;82(2):120-126. PMID: 36562637.

S tudy of neuropathological changes and dementia in 100 centenarians in The 90+ Study. Neuville R, Biswas R, Ho CC, Bukhari S, Sajjai SA, Paganini-Hill A, Montine TJ, Corrada MM, Kawas CH. Alzheimers Dement. 2023 Aug;19(8):3417-3425 [Online 2023 Feb 16]. PMID: 36795955. PMCID: PMC10427735 

Self-reported sleep in relation to risk of dementia a quarter of a century later at age 90+: The 90+ Study. Melikyan ZA, Kawas CH, Paganini-Hill A, Phelan MJ, Jian L, Mander BA, Corrada MM. Behav Sleep Med. 2023 Sep 3;21(5):620-632 [Online 23 Nov 2022]. PMID: 37540023 

Alzheimer’s Disease Neuropathologic Change and Vitamin Supplement Use Decades Earlier: The 90+ Study. Paganini-Hill A, Bukhari SA, Montine TJ, Corrada MM, Kawas CH. Alzheimer Dis Assoc Disord. 2023 Jan-Mar 01;37(1):1-6. PMID: 36821174. 

Superior global cognition in oldest-old is associated with resistance to neurodegenerative pathologies: Results from The 90+ Study. Biswas R, Kawas CH, Montine TJ, Bukhari SA, Jiang L, Corrada MM. J Alzheimers Dis. 2023;93(2):561-575. [Online 2023 Apr 10]. PMID: 37066908 

Characterization of hippocampal sclerosis of aging and its association with other neuropathologic changes and cognitive deficits in the oldest old. Sordo L, Qian T, Bukhari SA, Nguyen KM, Woodworth DC, Head E, Kawas CH, Corrada MM, Montine TJ, Sajjadi SA. Acta Neuropathol. 2023 Sep;146(3):415-432. [Online 2023 Jun 29]. PMID: 37382680. PMCID: PMC10412485. 

Characterizing pure Limbic-predominant Age-related TDP-43 Encephalopathy in the Oldest-Old: A Case Series. Leiby AC, Scambray KA, Nguyen HL, Basith F, Fakhraee S, Melikyan ZA, Bukhari SA, Montine TJ, Corrada MM, Kawas CH, Sajjadi SA. J Alzheimers Dis. [Online 2023 Sep 19]. PMID: 37742640.

White matter microstructural correlates of associative learning in the oldest‑old . Merenstein JL, Corrada MM, Kawas CH, Bennett IJ. Cogn Affect Behav Neurosci. 2022 Sep; PMID: 36163584.

Impact and risk factors of Limbic Predominant Age–Related TDP-43 Encephalopathy Neuropathologic Change in an oldest old cohor t. Sajjadi SA, Bukhari S, Scambray K, Yan R, Kawas CH, Montine TJ, Corrada MM. Neurology. 2023 Jan 10;100(2):e203-e210. [Online 2022 Oct 27]; PMID: 36302666. PMCID: PMC9841447. 

Reduced structural connectivity of the medial temporal lobe including the perforant path is associated with aging and verbal memory impairment. Granger SJ, Perez LC, Larson MS, Phelan M, Keator D, Janecek J, Sathishkumar M, Smith A, McMillan L, Greenia D, Corrada MM, Kawas CH, Yassa MA. Neurobiol Aging. 2022 Nov;121:119-128. PMID: 36434930. PMCID: PMC9841447. 

Methylation differences in Alzheimer’s disease neuropathologic change in the aged human brain. Lang AL, Eulalio T, Fox E, Yakabi K, Bukhari SA, Kawas CH, Corrada MM, Montgomery SB, Heppner FL, Capper D, Nachun D, Montine TJ. Acta Neuropathol Commun. 2022 Nov; 10:174. PMID: 36447297. PMCID: PMC984144.7

Frequency of LATE neuropathologic change across the spectrum of Alzheimer’s Disease neuropathology: combined data from 13 community-based or population-based autopsy cohorts . Nelson PT, Brayne C, Flanagan ME, Abner EL, Agrawal S, Attems J, Castellani RJ, Corrada MM, Cykowski MD, Di J, Dickson DW, Dugger BN, Ervin JF, Fleming J, Graff-Radford J, Grinberg LT, Hokkanen SRK, Hunter S, Kapasi A, Kawas CH, Keage HAD, Keene CD, Kero M, Knopman DS, Kouri N, Kovacs GG, Labuzan SA, Larson EB, Latimer CS, Leite REP, Matchett BJ, Matthews FE, Merrick R, Montine TJ, Murray ME, Myllykangas L, Nag S, Nelson RS, Neltner JH, Nguyen AT, Petersen RC, Polvikoski T, Reichard RR, Rodriguez RD, Suemoto CK, Wang SHJ, Wharton SB, White L, Schneider JA. Acta Neuropatol. Published online Jul 2022. PMID: 35697880.

Cognition, function, and prevalent dementia in centenarians and near-centenarians: an individual participant data (IPD) met-analysis of 18 studies. Leung Y, Barzilai N, Batko-Szwaczka A, Beker N, Boerner, K, Brayne C, Brodaty H, Cheung KS, Corrada MM, Marlow T, Crawford JD, Galbussera A, Yasuyuki G, Holstege H, Hulsman M, Ishioka YL, Jopp D, Kawas C, Kaye J, Kochan NA, Lau BH, Lipnicki DM, Lo J, Lucca U, Makkar SR, Marcon G, Martin P, Meguro K, Milman, S, Poon LW, Recchia A, Ribeiro O, Riva E, Rott C, Sikkes SAM, Skoog I, Stephan B, Szewieczek J, Teixeira L, Tettamanti M, Wilczyński K, Sachdev PS.  Alzheimers Dement . Accepted for publication.

Posterior white matter hyperintensities are associated with reduced medial temporal lobe subregional integrity and long-term memory in older adults. Rizvi B, Sathishkumar M, Kim S, Márquez F, Granger SJ, Larson MS, Miranda BA, Hollearn MK, McMillan L, Nan B, Tustison NJ, Lao PJ, Brickman AM, Greenia D, Corrada MM, Kawas CH, Yassa MA. Neuroimage Clin. 2022 Dec 28;37:103308. PMID: 36586358. 

AI-enabled in silico immunohistochemical characterization for Alzheimer’s disease . He B, Bukhari S, Fox E, Abid A, Shen J, Kawas C, Corrada M, Montine T, Zou J. Cell Rep Methods. Published online Mar 2022;2(4):100191. PMID: 35497493.

Hippocampal dentate gyrus integrity revealed with ultrahigh resolution diffusion imaging predicts memory performance in older adults . Granger SJ, Colon-Perez L, Larson MS, Bennet IJ, Phelan M, Keator DB, Janecek JT, Sathishkumar MT, Smith AP, McMillan L, Greenia D, Corrada MM, Kawas CH, Yassa MA. Hippocampus. Published online July 2022; doi: 10.1002/hipo.23456. PMID: 35838075.

Dementia is associated with medial temporal atrophy even after accounting for neuropathologies. Woodworth DC, Sheikh-Bahaei N, Scambray KA, Phelan MJ, Corrada MM, Kawas CH, Sajjadi SA. Brain Commun 2022 Mar 7; 4(2):fcac052. PMID: 35350552 PMCID: PMC8952251.

Cognitive resilience to three dementia-related neuropathologies in an oldest-old man: A case report from The 90+ Study . Melikyan ZA, Corrada MM, Leiby AM, Sajjadi SA, Bukhari S, Montine TJ, Kawas CH. Neurobiol Aging. Mar 2022;116:12-15. PMID: 35526514.

Gait Speed Reference Values for Adults Aged 90 and Older:  The 90+ Study . Colcord KA, Kawas CH, Corrada MC.. J Geriatr Phys Ther . Accepted for publication.

Association of cognition and dementia with neuropathologic changes of Alzheimer’s disease and other conditions in the oldest-old. Montine TJ, Corrada MM , Kawas CH, Bukhari MS, White LR, Tian L, Cholerton BA. Neurology . Published online Jun 2022. PMID: 35705500.

Utility of MRI in the diagnosis of hippocampal sclerosis of aging . Woodworth DC, Nguyen HL, Khan Z, Kawas CH, Corrada MM, Sajjadi SA.. Alzheimers Dement. 2021 May;17(5):847-855. [Epub Dec 7, 2020] PMID: 33615673.

What have we learned from cognition in the oldest-old . Kawas CH, Legdeur N, Corrada MM. Curr Opin Neurol. 2021 Apr 1;34(2):258-265. PMID: 33560671.

Neuroimaging in the Oldest-old: A review of the literature. Woodworth DC, Scambray KA, Corrada MM, Kawas CH, Sajjadi SA.  J Alzheimers Dis. 2021;82(1):129-147, 2021.

Norms and equivalences for MoCA-30, MoCA-22, and MMSE in the oldest-old. Melikyan ZA, Malek-Ahmadi M, O’Connor K, Atri A, Kawas CH, Corrada MM. Aging Clin Ex Res . 2021 May 29. PMID: 34050916.

Age affects white matter microstructure and episodic memory across the older adult lifespan. Merenstein JL, Corrada MM, Kawas CH, Bennett IJ. Neurobiol Aging. 2021 Jul 4;106:282-291. PMID: 34332220.

Kidney function is not related to brain amyloid burden on PET imaging in the 90+ Study cohort . Lau WL, Fisher M, Greenia D, Troutt H, Fletcher E, De Carli C, Corrada MM, Kawas CH, Paganini-Hill A. Front Med. 2021 Sep 20;8:671945. PMID: 34616751.

Regional Cortical Thickness Predicts Top Cognitive Performance in the Elderly . Dominguez EN, Stark S, Ren Y, Corrada MM, Kawas C, Stark C Front Aging Neurosci. 2021 Nov 4; 13:751375. PMID: 34803657.

Prior endogenous and exogenous estrogen and incident dementia in the 10th decade of life: The 90+ Study . Paganini-Hill A, Corrada MM, Kawas CH. Climacteric 23(3):311-315. [Epub Feb 28, 2020]. PMID: 32107945. PMCID: PMC7210048

Cystatin C, cognition and brain MRI findings in 90+ year-olds. Lau WL, Fisher M, Greenia D, Floriolli D, Fletcher E, Singh B, Sajjadi AS, Corrada MM, Whittle C, Kawas CH, Paganini-Hill A. Neurobiol Aging. 93:78-84, 2020. PMID: 32699142. PMCID: PMC7307913

Successful cognitive aging: What the oldest-old can teach us about resistance and resilience [editorial].  Kawas CH, Corrada MM. Neurology 95(8):329-330, 2020. PMID: 32699142.

Mechanisms of cerebral microbleeds. Wadi LC, Grigoryan MM, Kim RC, Kim J, Corrada MM, Paganini-Hill A, Fisher MJ J Neuropath Exp Neur 42(2):1093-1099, 2020. PMID: 32930790. PMCID: PMC7580489.

Cognition and Political Ideology in Aging . Fisher M, Phoenix D, Powell S, Mousa M, Rosenberg S, Greenia D, Corrada MM, Kawas CH, Paganini-Hill A. JAGS   [Epub Oct 31, 2020]. PMID: 33128770.

The Neural Substrate of Memory Impairment in the Oldest old with Dementia; The 90+ Study. S. Ahmad Sajjadi, Nasim Sheikh-Bahaei, Davis Woodworth, Dana Greenia, Maria Corrada, Claudia Kawas.Neurology; April 09, 2019; 92.P5.1-021.

What Are the Later Life Contributions to Reserve, Resilience, and Compensation? Neurobiology of Aging. Denise Park; Sara N Burke; Elizabeth C Mormino; Emily J Rogalski; Claudia H Kawas; Robert J Willis. 2019 Nov;83:140-144. doi: 10.1016/j.neurobiolaging.2019.03.023. PMID:31732017   PMCID: PMC6989050

Concepts for brain aging: resistance, resilience, reserve, and compensation. Montine TJ, Cholerton BA, Corrada MM, Edland SD, Flanagan ME, Hemmy LS, Kawas CH, White LR. Alzheimers Res Ther 11(1):22, 2019. PMID: 30857563.

Blood pressure circadian variation, cognition, and brain imaging in 90+ year-olds. Paganini-Hill A, Bryant N, Corrada MM, Greenia DE, Fletcher E,  Singh B, Floriolli DR, Kawas CH, Fisher MJ.  Front Aging Neurosci . Apr 17;11:54[Epub Apr 17, 2019].PMID: 31057391.

Apolipoprotein E/Amyloid beta complex accumulates in AD cortical synapses via apoE receptors and is enhanced by APOE4. Bilousova T, Melnik M, Miyoshi E, Gonzalez BL, Poon WW, Vinters HV, Miller CA, Corrada MM, Kawas CH, Hatami A, Albay R III, Glabe C, Gylys KH. Am J Pathol. 189(8):1621-1636. [Epub May 17, 2019]. PMID: 31108099.

Neuropsychological test norms in cognitively intact oldest-old. Melikyan ZA, Corrada MM, Dick MB, Paganini-Hill A, Kawas CH. J Int Neuropsychol Soc. 25 (5):530-545, 2019. [Epub May 24, 2019]. PMID: 31122309.

White matter hyperintensities and hippocampal atrophy in relation to cognition: The 90+ Study. Legdeur N, Visser PJ, Woodworth DC, Muller M, Fletcher E, Maillard P, Scheltens P, DeCarli C, Kawas CH, Corrada MM. J Am Geriatr Soc . 67(9):1827-1834.[Epub Jun 6, 2019]. PMID:31169919.

Recruiting the oldest‐old for clinical research . Melikyan ZA, Greenia DE, Corrada MM, Hester MM, Kawas C, Grill JD. Alzheimer Dis Assoc Disord [Epub May 4, 2018]. PMID:29734262.

Non‐Alzheimer’s disease contributions to dementia and cognitive resilience in The 90+ Study . Robinson JL, Corrada MM, Kovacs GG, Dominique M, Caswell C, Xie SX, Lee VMY, Kawas CH, Trojanowski JQ.  Acta Neuropathol 136:377‐388, 2018. [Epub Jun 18, 2018]. PMID:29916037.

Sleep, hippocampal volume, and cognition in adults over 90 years old. Sabeti S, Al‐Darsani Z, Mander BA, Corrada MM, Kawas CH. Aging Clin Exp Res. [Epub Sep 3, 2018]. PMID:30178444.

Risk factors of hippocampal sclerosis in the oldest old: The 90+ Study . Trieu T, Sajjadi ,Kawas CH, Nelson PT, Corrada MM. Neurology 91(19):e1788-e1798, 2018. [Epub Oct 12, 2018]. PMID: 30315072

Positive mental attitude associated with lower 35-year mortality: The Leisure World Cohort Study . Paganini-Hill A, Kawas CH, Corrada MM. J Aging Res [Epub Nov 25, 2018]. PMID: 30595919.

Age of onset of hypertension and risk of dementia in the oldest-old: The 90+ Study.  Corrada MM, Hayden KM, Paganini-Hill A, Bullain SS, Paganini-Hill A, DeMoss J, Aguirre C, Brookmeyer R, Kawas CH. Alzheimer Dement. 13(2):103-110, 2017. [Epub Jan 16, 2017]. PMID: 28108119.

Lower likelihood of falling at age 90+ is associated with daily exercise a quarter of a century earlier: The 90+ Study.  Paganini-Hill A, Greenia DE, Perry SM, Sajjadi SA, Kawas CH, Corrada MM. Age Ageing. 46(6):951-957, 2017. [Epub Mar 21, 2017]. PMID: 28369185.

Age-related white matter integrity differences in oldest-old without dementia.   Bennett IJ, Greenia D, Maillard P, Sajaadi SA, DeCarli C, Corrada MM, Kawas CH. Neurobiol Aging 56: 108-114, 2017. [Epub Apr 26, 2017]. PMID: 28527525.

Cancer – Incidence, prevalence and mortality in the oldest-old: A comprehensive review.  Nolen SC, Evans MA, Fischer A, Corrada MM, Kawas CH, Bota DA.  Mech Aging Dev 164:113-126, 2017. [Epub May 11, 2017]. PMID: 28502820.

Forecasting the prevalence of pre-clinical and clinical Alzheimer’s disease in the  United States.  Brookmeyer R, Abdallah N, Kawas CH,  Corrada MM. Alzheimer Dement 14:121-129, 2018.  [Epub Dec 7, 2017]. PMID: 29233480.

Prevalence of Frailty and Factors Associated with Frailty in Individuals Aged 90 and Older: The 90+ Study.   Lee DR, Kawas CH, Gibbs L, Corrada MM. J Am Geriatr Soc.  2016 Nov;64(11):2257-2262. PMID: 27590837.

Microinfarcts are common and strongly related to dementia in the oldest-old: The 90+ study.   Corrada MM, Sonnen JA, Kim RC, Kawas CH. Alzheimers Dement . 2016 Aug;12(8):900-8. PMID: 27243907.

Sound Body Sound Mind? Physical Performance and the Risk of Dementia in the Oldest-Old: The 90+ Study.   Bullain SS, Corrada MM, Perry SM, Kawas CH. J Am Geriatr Soc.   2016 Jul;64(7):1408-15. PMID: 27377238.

Impact of interventions to reduce Alzheimer’s disease pathology on the prevalence of dementia in the oldest-old.   Brookmeyer R, Kawas CH, Abdallah N, Paganini-Hill A, Kim RC, Corrada MM. Alzheimers Dement.  2016 Mar;12(3):225-32. PMID: 26900132.

Synaptic Aβ oligomers precede p‐tau and differentiate high pathology control cases . Bilousova T, Miller CA, Poon WW, Vinters HV, Corrada MM, Kawas CH, Hayden EY, Teplow DB, Glabe C, Albay R 3rd, Cole GM, Teng E, Gylys KH.  Am J Pathol.  2016 Jan; 186(1):185‐198. PMID: 26718979.

Brain‐derived neurotrophic factor and TrkB expression in the “oldest‐old,” the 90+Study: correlation with cognitive status and levels of soluble amyloid‐beta. Michalski B, Corrada MM, Kawas CH, Fahnestock M. Neurobiol Aging . 2015 Dec.; 36(12):3130‐3139. PMID: 26410307.

Multiple pathologies are common and related to dementia in the oldest-old: The 90+ Study.   Kawas CH, Kim RC, Sonnen JA, Bullain SS, Trieu T, Corrada MM.  Neurology . 2015 Jul 15. PMID:26180144.

Lifestyle Factors and Dementia in the Oldest-old: The 90+ Study.  Paganini-Hill A, Kawas CH, Corrada MM.  Alzheimer Dis Assoc Disord . 2015 Mar 6. PMID:25710250.

Antioxidant vitamin intake and mortality: the Leisure World Cohort Study.  Paganini-Hill A, Kawas CH, Corrada MM.  Am J Epidemiol . 2015 Jan 15;181(2):120-6. PMID:25550360.

Intracellular amyloid and the neuronal origin of Alzheimer neuritic plaques.  Pensalfini A, Albay R 3rd, Rasool S, Wu JW, Hatami A, Arai H, Margol L, Milton S, Poon WW, Corrada MM, Kawas CH, Glabe CG.   Neurobiol Dis . 2014 Nov;71:53-61. doi: 10.1016/j.nbd.2014.07.011. Epub 2014 Aug 1. PMID:25092575.

ABCC9 gene polymorphism is associated with hippocampal sclerosis of aging pathology.   Nelson PT, Estus S, Abner EL, Parikh I, Malik M, Neltner JH, Ighodaro E, Wang WX, Wilfred BR, Wang LS, Kukull WA, Nandakumar K, Farman ML, Poon WW, Corrada MM, Kawas CH, Cribbs DH, Bennett DA, Schneider JA, Larson EB, et al. Acta Neuropathol. 127(6):825-843, 2014. PMID: 24770881.

Exponential increases in the prevalence of disability in the oldest old: a Canadian national survey. Guay M, Dubois MF, Corrada M, Lapointe-Garant MP, Kawas C.  Gerontology. 60(5):395-401, 2014. PMID: 24818716.

Perforant path synaptic loss correlates with cognitive impairment and Alzheimer’s disease in the oldest-old. Robinson JL, Molina-Porcel L, Corrada MM, Raible K, Lee EB, Lee VM, Kawas CH, Trojanowski JQ.   Brain . 137(Pt 9):2578-2587, 2014. PMID: 25012223. PMCID: 4132652.

Intracellular amyloid and the neuronal origin of Alzheimer neuritic plaques.  Pensalfini A, Albay R, 3rd, Rasool S, Wu JW, Hatami A, Arai H, Margol L, Milton S, Poon WW, Corrada MM, Kawas CH, Glabe CG.   Neurobiol Dis . 71C:53-61, 2014. PMID: 25092575.

Dementia in the oldest-old .  Bullain SS, Corrada MM.   Neurology Continuum (Minneap Minn)  19(2 Dementia):457-469, 2013.  PMID: 23558489.

DRD4 genotype predicts longevity in mouse and human.  Grady D, Thanos P, Corrada MM, Barnett J, Ciobanu V, Shustarovich D, Napoli A, Grandy D, Moyzis A, Rubinstein M, Wang G-J, Kawas C, Chen C, Dong Q, Wang E, Volkow N, Moyzis R. Journal of Neuroscience  33:286-291,2013. PMID: 23283341.

Responders Versus Nonresponders in a Dementia Study of the Oldest Old: The 90+ Study.   Paganini-Hill A, Ducey B, Hawk M. American Journal of Epidemiology . 2013 Apr 7. PMID: 23568592.

Amyloid imaging and cognitive decline in non-demented oldest-old: The 90+ Study.   Kawas CH, Greenia DE, Bullain SS, Clark CM, Pontecorvo MJ, Joshi AD, Corrada MM.   Alzheimer’s & Dementia . 2013 Mar 9:199-203. [Epub 2012 Nov 1]. PMID: 23164550. PMCID: 3604036.

Neocortical b-amyloid area is associated with dementia and APOE in the oldest-old. Berlau DJ, Corrada MM, Robinson JL, Geser F, Arnold SE, Lee, VM-Y, Kawas CH, Trojanowski JQ. Alzheimer’s & Dementia. 2013 Mar 6: pii: S1552-5260. PMID: 23474043.

Aging in Place in a Retirement Community: 90+ Year Olds.   Paganini-Hill A. J Hous Elderly. 2013 Jan 1;27(1-2):191-205. PMID: 25288828.

APOE genotype, dementia, and mortality in the oldest-old: The 90+ Study.  Corrada MM, Paganini-Hill A, Berlau DJ, Kawas CH.  Alzheimer’s & Dementia . 2013 Jan 9(1):12-8. [Epub 2012 Nov 2]. PMID: 23123227.

Poor Physical Performance and Dementia in the Oldest-Old: The 90+ Study.  Bullain SS, Corrada MM, Shah BA, Mozaffar FH, Panzenboeck M, Kawas CH. JAMA Neurology . 2013 Jan 7(1):107-13. PMID: 23090391.

Hypertension and dementia in the elderly: the leisure world cohort study.   Paganini-Hill A. Int J Hypertens . 2012;2012:205350. PMID: 22229084.

Alzheimer disease pathology and longitudinal cognitive performance in the oldest-old with no dementia.  Balasubramanian AB, Kawas CH, Peltz CB et al.   Neurology . 2012 Aug 28;79:915-921. PMID: 22895581.

Cognitive impairment in non-demented oldest-old:  prevalence and relationship to cardiovascular risk factors . Peltz CB, Corrada MM, Berlau DJ, Kawas CH.  Alzheimer’s & Dementia.  2012; 8(2):87-94. [Epub Nov 4, 2011]. PMID: 22055654. PMCID: 3276712.

A population-based clinicopathological study in the oldest-old: The 90+ Study.  Corrada MM, Berlau DJ, Kawas CH.  Curr Alzheimer Res.  2012;9:709-717. PMID: 22471863. PMCID: 3409303.

Disability in the Oldest-old: Incidence and Risk Factors in The 90+ Study.  Berlau DJ, Corrada MM, Peltz CB, Kawas CH.   Am J Geriatr Psychiatry . 2012, 20:159-168. PMID: 22273736. PMCID: 3266513.

Neocortical and hippocampal amyloid-beta and tau measures associate with dementia in the oldest-old.  Robinson JL, Geser F, Corrada MM, Berlau DJ, Arnold SE, Kawas CH, Lee VM, Trojanowski JQ.  Brain . 134(Pt 12):3705-3712, 2011. PMID: 22120149. PMCID: 3235569.

Lifestyle practices and cardiovascular disease mortality in the elderly: the Leisure World Cohort Study. Paganini-Hill A. Cardiol Res Pract. 2011;2011:983764.

Activities and mortality in the elderly: the Leisure World Cohort Study. Paganini-Hill A, Kawas CH, Corrada MM. J Gerontol A Biol Sci Med Sci. 2011;66:559-567. PubMedCentID: 3074957.

Incidence of dementia in oldest-old with amnestic MCI and other cognitive impairments. Peltz CB, Corrada MM, Berlau DJ, Kawas CH. Neurology. 2011; 77:1906-1912. PMID: 22076544. PMCID: 3233189

Bathing as a potential target for disability reduction in the oldest old. Berlau DJ, Corrada MM, Peltz CB, Kawas CH. Am J Public Health. 2011 Feb ;101:200-201.

Diagnosing dementia in the oldest-old. Brumback-Peltz C, Balasubramanian AB, Corrada MM, Kawas CH. Maturitas. 2011 Oct ;70:164-168. PubMedCentID: 3171568.

Being overweight in adults aged 70-75 is associated with a reduction in mortality risk compared with normal BMI . Corrada MM, Paganini-Hill A. Evid Based Med. 2010;15:126-127.

Dementia incidence continues to increase with age in the oldest-old: The 90+ Study . Corrada MM, Brookmeyer R, Paganini-Hill A, Berlau D, Kawas CH. Ann Neurol. 2010;67:114-121.

Abnormal EEGs in cognitively and physically healthy oldest old: findings from The 90+ Study. Peltz CB, Kim HL, Kawas CH. J Clin Neurophysiol. 2010;27:292-295.

High levels of serum C-reactive protein are associated with greater risk of all-cause mortality, but not dementia, in the oldest-old: Results from The 90+ Study. Kravitz BA, Corrada MM, Kawas CH. J Am Geriatr Soc. 2009;57:641-646.

The prevalence of disability in the oldest-old is high and continues to increase with age: findings from The 90+ Study. Berlau DJ, Corrada MM, Kawas CH. Int J Geriatr Psychiatry. 2009;24:1217-1225.

APOE epsilon2 is associated with intact cognition but increased Alzheimer pathology in the oldest old. Berlau DJ, Corrada MM, Head E, Kawas CH. Neurology. 2009;72:829-834.

Synaptic proteins, neuropathology and cognitive status in the oldest-old. Head E, Corrada MM, Kahle-Wrobleski K, Kim RC, Sarsoza F, Goodus M, Kawas CH. Neurobiol Aging. 2009;30:1125-1134.

Elevated C-reactive protein levels are associated with prevalent dementia in the oldest-old. Kravitz BA, Corrada MM, Kawas CH. Alzheimers Dement. 2009;5:318-323.

Prevalence of dementia after age 90: results from The 90+ Study. Corrada MM, Brookmeyer R, Berlau D, Paganini-Hill A, Kawas CH. Neurology. 2008;71:337-343.

The oldest old and The 90+ Study. Kawas CH. Alzheimers Dement. 2008;4:S56-59.

Sensitivity and specificity of the mini-mental state examination for identifying dementia in the oldest-old: The 90+ Study. Kahle-Wrobleski K, Corrada MM, Li B, Kawas CH. J Am Geriatr Soc. 2007;55:284-289.

Type of alcohol consumed, changes in intake over time and mortality: the Leisure World Cohort Study. Paganini-Hill A, Kawas CH, Corrada MM. Age Ageing. 2007;36:203-209.

Neuropsychological data in nondemented oldest-old: The 90+ Study. Whittle C, Corrada MM, Dick M, Ziegler R, Kahle-Wrobleski K, Paganini-Hill A, Kawas CH. J Clin Exp Neuropsychol. 2007;29:290-299.

Dissociation of neuropathologic findings and cognition: case report of an apolippoprotein E e2/e2 genotype. Berlau DJ, Kahle-Wrobleski K, Head E, M G, Kim R, Kawas CH. Arch Neurol. 2007;64:1193-1196.

Non-alcoholic beverage and caffeine consumption and mortality: the Leisure World Cohort Study. Paganini-Hill A, Kawas CH, Corrada MM. Prev Med. 2007;44:305-310.

Increased longevity in older users of postmenopausal estrogen therapy: the Leisure World Cohort Study. Paganini-Hill A, Corrada MM, Kawas CH. Menopause. 2006;13:12-18.

Association of body mass index and weight change with all-cause mortality in the elderly. Corrada MM, Kawas CH, Mozaffar F, Paganini-Hill A. Am J Epidemiol. 2006;163:938-949.

Alzheimer’s and dementia in the oldest-old: a century of challenges. Kawas CH, Corrada MM. Curr Alzheimer Res. 2006;3:411-419.

Computerized neuropsychiatric assessment of geriatric subjects by content analysis of brief samples of their speech . Gottschalk LA, Kawas CH, Hoang A, Bechtel RJ. Comput Inform Nurs. 2004;22:351-355.

90+ Newsletters

Current News

¿Cómo podrías llegar a cumplir más de 90 años de edad?

Cnn en español  .

The Latest on Alzheimer’s Disease: What Researchers Are Learning About the Disease

Houston public media.

Dana Greenia, RN, MS Interviewed About The 90+ Study

Laguna woods village tv station – october 2022.

Laguna Woods resident endured horrors of Holocaust and got a fresh start in the U.S.

The orange county register – october 2022.

Why more of us are living to 100

Mpr news with kerri miller- april 2021.

Link for 60 Minutes:

The 90+ study on cbs’s 60 minutes 2020.

The 90+ Study was featured for a second time on the November 22nd, 2020 broadcast of 60 Minutes with Leslie Stahl. You can watch the full segment here .

To watch the 60 Minutes segment from 2014, scroll down to the Past News section below.

Late-age onset of high blood pressure may reduce risk of dementia, UCI study finds

Los angeles times- january 2017 .

When the Pressure Is High the Dementia Is Low

Sounds of science podcasts- january 2017.

The 90+ Study  was featured on the May 4th, 2014 broadcast of 60 Minutes with Leslie Stahl. You can watch the full episode with the link below.

The 90+Study on CBS’s 60 Minutes 2014

Living past 90: Caffeine, alcohol, and extra weight may be good for you

CBS News – 2014

Run on the local Laguna Woods Village channel, Dr. Claudia Kawas discusses the 90+ Study and the study’s recently reopened recruitment

Laguna Woods Village television broadcast- 2015

Dr. Claudia Kawas also made an appearance on Fox’s Good Day LA to respond to the 60 Minutes episode after it aired.

Phone: (949) 768-3635                   Email: [email protected]

The staff of The 90+ Study is truly grateful for all you have done to further our understanding of ways to aid future generations in leading long, productive and healthy lives. This is YOUR LEGACY .

Through all of your passion and dedication to our mission, The 90+ Study at the University of California, Irvine has achieved a number of great successes. Our investigators, Drs. Claudia Kawas, Maria Corrada, and Annlia Paganini-Hill, are extremely well published in the field of aging and dementia and continue to be very successful in break-through research around the world.

Ways to donate

Click an option below:

• Click the button above, print the PDF and complete the form
• Checks are payable to “ UCI FOUNDATION ” with “ THE 90+ STUDY ” written in the memo area
•  Mail the filled in form and your check to:

         Claudia Kawas M.D., 1121 Gillespie, Irvine, CA 92697-4540

• Click the “Online Donations” button above and complete the online form.
• Be sure that The 90+ Study is the selected designation

Interested in volunteering or know someone over 90 years old who might want to participate in The 90+Study ?

Take a look at the eligibility criteria listed below

Click on the photo for a larger view.

Contact us today to get started, phone:   (949) 768-3635, email:    [email protected], mailing address:, 24361 el toro road suite 150, laguna woods, ca 92637.

The FDA Has Approved Aducanumab (Aduhelm™). Now What? By Joshua Grill, PhD Watch the video >

The Problem With Post-Approval Required Studies By Daniel Gillen, PhD

If the FDA approves Biogen’s Alzheimer’s treatment, I won’t prescribe it By Jason Karlawish

Aducanumab Approved for Treatment of Alzheimer’s Disease By Alzheimer’s Association

FDA Approves New Alzheimer’s Drug By Alzheimer’s Orange County

Listen: Two Alzheimer’s experts with opposing viewpoints on Aduhelm By Stat First Opinion Podcast

ABOUT BRAIN DONATION

At present, a definitive diagnosis of Alzheimer’s disease is made by examining brain tissue. An autopsy provides accurate and comprehensive information about the cause of the clinical diagnosis of dementia during life.  Many families find that receiving the final pathological diagnosis provides closure and resolution to the caregiving experience and important information about their own medical risks.

In addition, the autopsy contributes greatly to our scientific understanding of the effects of the disease on the brain and may lead to better treatments in the future.

Finally, brain donation provides the opportunity for the individual and their family to provide a gift of hope to future generations in the fight against Alzheimer’s and other brain diseases.

Participants enrolled in UCI’s 90+ Study and who have agreed to in-person visits and longitudinal follow-up, are eligible for brain donation. Brain donation by non-research participants is, unfortunately, far less valuable to scientific study.

HOW CAN BRAIN DONATION BE ARRANGED?

A signed informed consent form is all that is needed to be enrolled in the program.  Without the signed consent, the legal next-of-kin must authorize the brain autopsy before it can be performed.

DOES BRAIN DONATION GO AGAINST RELIGIOUS TEACHING?

To donate your brain for the betterment of humanity and to improve the lives of others in the future is compatible with the teachings of nearly all religions.  If you are concerned about brain donation and your religious faith, we encourage you to discuss this issue with your spiritual leader.

WHAT EFFECT DOES BRAIN DONATION HAVE ON FUNERAL ARRANGEMENTS?

A brain autopsy will have little or no effect on funeral arrangements.  The procedure is performed very carefully and does not interfere with plans for open casket viewing or cremation.

WHAT HAPPENS TO THE BRAIN ONCE IT HAS BEEN DONATED?

The brain is examined by a pathologist to establish a definitive diagnosis.  This process is quite complex and can take several months to complete.  Once finished, a comprehensive report is sent to the participant’s family.  After the examination, portions of the brain will be stored for future investigations by researchers at the UCI ADRC and Stanford University. The identity of all brain donors remains strictly confidential.

Strides in research can only be made through the generosity of others. It is through these gifts that we can help promote research and fuel determination to find answers and a cure.

BRAIN DONATION PROGRAM

The 90+ Study 24361 El Toro Road, Suite 150 Laguna Woods, CA 92637 Telephone: 949.768.3635 Fax: 949.768.7695

For more information about brain donation, please consider reading the following articles:

Why My Grandmother Carried a Plastic Brain in her Purse 

Will my soul go to heaven if they take my brain? Beliefs and worries about brain donation among four ethnic groups

‘Brain Banks’: Why these scientists want your brain

Autopsy and Religion

Religious Views on Organ Donation

(949) 768-3635

Laguna woods, ca 92867, [email protected], https://www.facebook.com/the90study, https://twitter.com/the90study, search website.

• Dr. Leigh Turner awarded grant to study ethics of using biocomputing to build neural networks September 10, 2024
• Dr. Kei Igarashi’s Nature article highlights the role of “item memory” August 22, 2024
• Listening to patients unable to communicate August 15, 2024
• Keeping sleep in mind: poor sleep and dementia risk July 24, 2024
• Dr. Sajjadi comments on former LA County sheriff wandering incident July 16, 2024

Participate

CLINICAL TRIALS

Phone: 949.824.0008 Email: [email protected]

UCI C2C REGISTRY www.c2c.uci.edu

ADMINISTRATION

2642 Biological Sciences III Irvine, CA 92697-4545

Phone: 949.824.3253 Fax: 949.824.0885

RESEARCH CLINIC

1100 Gottschalk Medical Plaza Irvine, CA 92697-4285

Phone: 949.824.2382 Fax: 949.824.3049

© 2024 UCI MIND.

• Message from the Director
• Affiliated Members
• Executive Committee
• Leadership Council
• Annual Update
• Institute Highlights
• Founding Director
• Privacy Policy
• About the ADRC
• Administrative Core
• Clinical Core
• Data Management and Statistics Core
• Neuropathology Core
• Outreach, Recruitment, and Engagement Core
• Induced Pluripotent Stem Cell Core
• Biomarker Core
• Down Syndrome Core
• Research Education Component
• Participate in a Study
• UCI C2C Registry
• Participant Hub
• Clinical Trials
• Featured Volunteers
• Down Syndrome Program
• The 90+ Study
• SoCal Alzheimer’s Disease Research Conference
• Ask the Doc Panels
• About Dementia
• Mild Cognitive Impairment
• Alzheimer’s Disease
• Vascular Dementia
• Lewy Body Dementia
• Frontotemporal Dementia
• Huntington’s Disease
• Supportive Services
• Diagnostic Toolkit
• Toolkit Manual
• Clinical Care Guidelines
• Assessment of Cognitive Complaints Toolkit
• Assessment of Cognitive Complaints Pocket Guide
• Communicating MCI Diagnoses
• Job Opportunities
• UCI MINDcast
• Event Calendar
• Make A Gift
• Gift Designations
• Planned Gifts
• Memorial Donations
• A December to Remember Gala

Privacy Overview

Stack Exchange Network

Stack Exchange network consists of 183 Q&A communities including Stack Overflow , the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Q&A for work

Connect and share knowledge within a single location that is structured and easy to search.

How old can references or sources in a thesis be?

I have read that references in scientific papers should be no more than 2-3 years old, since such fields move fast, and no more than 10 years for arts or related fields:

A good rule of thumb is to use sources published in the past 10 years for research in the arts, humanities, literature, history, etc. For faster-paced fields, sources published in the past 2-3 years is a good benchmark since these sources are more current and reflect the newest discoveries, theories, processes, or best practices.

However, I believe that's subjective, so how old is it for a reference to be "too old" to cite?

• online-resource

• 72 There is no "too old to cite". I've actually referenced some of Adolf Fick's and Einstein's original papers in my dissertation. (And they were such fun to read!) Also, that references need to have a certain age is nonsense. Where did you read this? –  user9482 Commented Apr 5, 2019 at 11:54
• 2 @Roland strictly speaking you are right: as written the OP states that a publication must be older than 2 years before you can cite it. However, given the content of the question I suspect that the OP intended to say that a publication must be younger than 2 years. –  Maarten Buis Commented Apr 5, 2019 at 12:01
• 4 No study is too old to cite, but not all studies "age well". Especially in fast paced discipline studies can easily be obsolete. However, this does not mean that all older studies in those disciplines become obsolete, just that many do. You can and should use those non-obsolete older ones. –  Maarten Buis Commented Apr 5, 2019 at 12:07
• 5 If you are still allowed to reference Plato, that's more than 10 years... –  Solar Mike Commented Apr 5, 2019 at 12:57
• 6 I notice the web page you cited says "A good rule of thumb is" and "is a good benchmark", which is a lot softer than your wording suggests, especially in trying to pin-point the exact suggested constraints. Also, the librarian's answer clearly seems to be designed for undergraduate research papers and projects, and a quick check shows the university serves almost entirely undergraduates. Finally, a look at the "Related FAQs" titles on the right side shows the kinds of things (allowing for a 40 year gap) covered in my required freshman English composition course. –  Dave L Renfro Commented Apr 5, 2019 at 13:19

8 Answers 8

References can be as old as they need to be to cover the material. I had some that were more than 30 years old. But if all of your references are "old," people are going to want to know why.

You must also be sure you cover the most current research in your field. A few in my own dissertation were for material published in the same year as my own work.

The link given in the comments and the revised question seems to be directed toward undergraduate research assignments, and the "ten years" reference is a part of an example assignment, not a requirement given by the Shapiro Library. The key idea in the link is that references must be "somewhat current."

For a thesis or dissertation, one must cover the field, including both early and very new research.

• 2 Indeed, I suspect that when flipping through a typical issue of a typical journal in most any field, one will find several papers whose references include items listed as "to appear" , or "forthcoming", or "under review", or "submitted", etc. –  Dave L Renfro Commented Apr 5, 2019 at 13:24
• 2 "References can be as old as they need to be" -- while I agree, the link the OP posted suggests that there are assignments saying "Sources must be published in the last 10 years". –  Ingo Commented Apr 5, 2019 at 13:27
• 2 @Ingo Well, yes, but that link seems directed at undergraduate research assignments, and in in fact, that "last ten years" bit is prefaced with, "If it’s a requirement for your assignment..." For a doctoral dissertation, one is expected to cover the field. –  Bob Brown Commented Apr 5, 2019 at 13:31
• 12 Something worth mentioning might be the difference between referencing research results, where you want to try and have relevant recent material, and referencing ideas, which might predate their use in actual research. For example, In my Master's thesis I referenced a pre-1900 paper by Karl Pearson for an idea he discussed that was important for my research, but then referenced modern research papers for my actual implementation. Another example might be natural selection; depending on the context, Darwin is an obvious reference. –  anjama Commented Apr 5, 2019 at 15:05
• 2 When I was an undergraduate in the late 70's we were told about the Science Citation Index, and it was pointed out that "Newton, I" was still being cited. –  Martin Bonner supports Monica Commented Apr 7, 2019 at 7:19

There is no rule about the age of citations. For example in my PhD-thesis I quoted some math-papers from 1600s that were originally written in latin (but those were exceptions).

Much more relavant than the year is the content of a citation and that you cover the relevant literature.

Also, you might want to include a few (relevant!) citations from recent years in order to show that you did your reading not just at the beginning of your thesis and then ignored everything afterwards.

• 6 In math it is common to cite old papers. 1600s is indeed exceptionally old but it is not uncommon to cite 10-100 years old papers. –  Yanko Commented Apr 5, 2019 at 19:22
• 3 I would say that it would be a bit unusual for a math paper to have most of its references under ten years old (unless the authors give only a very brief account of the context and there is only a handful of references in all). –  tomasz Commented Apr 5, 2019 at 20:37
• 2 @Yanko Ten years is old? Jeez, kids today. I doubt I've ever written a paper (including the ones I wrote more than ten years ago) that didn't cite something at least ten years old. –  David Richerby Commented Apr 6, 2019 at 17:58
• But did you really read those papers written in Latin? –  Dubu Commented Apr 8, 2019 at 12:33

I have cited a book on farming by Columella from the 1st century CE .

It provided crucial evidence for the use of a word at that time. But I did not take the evidence as the final say on the matter. I also cited 15th century academic analysis of the evidence as well as 21st century work. There is a fundamental difference between saying

It is true because X says so

X says so, so let us analyse it and cite more recent opinions on whether it is true.

In any discipline it may be necessary to contrast older and younger opinions on the same subject, and you will have to do some work yourself to argue that any given source, whatever its age, is - or is not - reliable.

As it happens, I rejected all the academic analysis and accepted my own interpretation of the original evidence. You as a researcher are expected to determine on a case-by-case basis what evidence needs to be cited, and what can be accepted.

Of course, at some stage, you have to accept that a certain claim is true because X says so. To do this you have to cite something that is fairly recent (which will depend on the discipline) and, if it not the most recent, argue why you are accepting it in preference to the most recent.

Your rule has a large fraction of exception that you should always consider. Make sure you cite the relevant papers for your claims and that you cite the papers which were the first introducing the idea. Don't cite a textbook for ideas just because they are recent. Instead, try to find and cite the original works.

If you cite an idea originating back to Aristoteles it does not make sense to use a recent source. The idea is that old! Also, if you want to prove your claim, that some method was used in the 70s, it's useful to cite papers written in the 70s.

• 2 This hits what I consider the key point. Each citation should be appropriate for its purpose. Documenting the origins of a question is different from documenting the state of the art in a rapidly changing research area. –  Patricia Shanahan Commented Apr 5, 2019 at 22:54

The rule you quote is total nonsense for the sciences, and I have a hard time taking it seriously for the humanities.

You cite whatever you need to cite, regardless of its age. Typically, if you're referring to something that is decades old, it's now either common knowledge (e.g., Newton's laws) so probably doesn't need citation at all, or it's in textbooks (which are probably more appropriate to cite than the original source). Both of those things are a consequence of age but age per se is a completely spurious reason to not cite something.

• 2 In the humanities it's outright laughable. Besides the fact that often our sources are necessarily quite a bit older (classicists will quote stuff from antiquity, medievalists from the medieval, etc, historians from their period of history), many things we study may only be taken up by someone every few years or decades even, so to even do a cursory review of prior work you're going to be citing old stuff unless you're on a very popular topic. –  user0721090601 Commented Apr 7, 2019 at 14:03
• 2 @guifa That's what I figured, but I was waiting for somebody else to say it, since "Scientist guesses what the humanities are like" is probably pretty laughable, too! –  David Richerby Commented Apr 7, 2019 at 15:16

A group of researchers published this very interesting paper:

The nearly universal link between the age of past knowledge and tomorrow’s breakthroughs in science and technology: The hotspot

From a pure data science perspective, they try to understand how the distribution of reference age affects the forward citations of an article. They analyze all publications (~ 28 million) in Web of Science published between 1945 - 2013.

Unfortunately, they do not show an aggregated histogram of age differences between a publication and its references. But in Fig. 1 we see the mean (0-50 years) and variance (0-4) for all published papers and it is all over the place. So the take away might be to cite what you want.

However, they echo in their paper the comments and answers that you got here. Impactful and hopefully good research seems to differ from the "cite what you want" approach. If you want to increase the likelihood of your work having an impact you should base your work on recent advances but also be aware of well-established theories or overlooked ideas from the past. They show this in the paper by finding a hotspot of highly cited papers that have a low mean age distance to their references but a high variance in age distance.

Here is a link to the paper (super interesting): http://advances.sciencemag.org/content/advances/3/4/e1601315.full.pdf

There's no limit on how old they can be. In biology people often cite Darwin (1859) and geneticists who work on pedigrees can cite government records from hundreds of years ago. Work involving theology may cite the Bible. Historians cite original documents from thousands of years ago. Sometimes a fun game is to see what the oldest citation you can get away with is. Plato or Aristotle is often a safe bet.

Generally, you are supposed to cite the oldest paper that made a discovery, as the credit belongs to them. When in doubt, you can cite one old and one new paper.

However, your work must be in the context of contemporary scientific literature. If you cite a 50 year old paper for a theory, you better make sure the theory has not been disproven in another paper published 30 years after. If you say the state of the art in a field is a paper published 10 years ago, it would look really bad if somebody brought up a 5 year old paper that advanced it further. This is why citing old material is risky: You can't easily tell that it's still current. If a paper came out last monday, chances are pretty low that somebody refuted it in that time.

• I'm sorry but this is terrible. You seem to be advocating not citing older work that you use, purely to avoid the embarrasment of being out of date. That's what you literature search is supposed to avoid. If you're using the 50-year-old theory, you need to cite something for it. If that theory has been refuted, you're going to look like an idiot whether you cite the original paper or not. If you're out-of-date on the state of the art, you need to find out what it really is. And that paper that came out last Monday also hasn't had time for anyone to check that it seems to be true! –  David Richerby Commented Apr 6, 2019 at 17:55
• @DavidRicherby I'm sorry but your comment is terrible. You seem to have confused a number of points. Notable among them is your mistaking numbers given as examples for actual universal rules. I'd recommend re-reading the post carefully. If you still have questions, I'd be happy to respond to them if you phrase it in a more constructive manner. –  Trusly Commented Apr 8, 2019 at 4:19
• I've re-read your answer and I stand by what I wrote. I'm not criticizing the numbers at all. I'm criticizing what appears to be a recommendation to avoid citing old stuff because it might be out of date and your literature search might have failed to spot that. If that's not what you meant, what did you mean? –  David Richerby Commented Apr 8, 2019 at 8:41
• @DavidRicherby I didn't say to avoid citing old stuff because it might be out of date. I said that when citing old material, it is especially important to make sure it's not obsolete. –  Trusly Commented Apr 9, 2019 at 19:47

To be honest, just like you’ve said, all of this is quite subjective... Personally, I believe that if a paper is relevant to the point you are trying to make and hasn’t been categorically disproven then it’s fair game. However, what I think is irrelevant; it depends on the person marking your dissertation and how they feel about it. Some academics I know don’t care while others do. I was once marked down for using a 7 year old paper as a reference even though it was very relevant to my work, simply because the lecturer marking my work didn’t want to see anything older than 5 years.

For the most part, it should be fine. Academics who insist on only recent papers are few, in my experience.

You must log in to answer this question.

Not the answer you're looking for browse other questions tagged citations thesis masters online-resource ..

• Featured on Meta
• User activation: Learnings and opportunities
• Preventing unauthorized automated access to the network

Hot Network Questions

• Frequent Statistics updates in SQL Server 2022 Enterprise Edition
• My one-liner 'delete old files' command finds the right files but will not delete them
• Would a material that could absorb 99.5% of light be able to protect someone from Night Vision?
• Returning to the US for 2 weeks after a short stay around 6 months prior with an ESTA but a poor entry interview - worried about visiting again
• Date not working correctly
• Trinitarian Christianity says Jesus was fully God and Fully man. Did Jesus (the man) know this to be the case?
• Does it ever make sense to have a one-to-one obligatory relationship in a relational database?
• Why are Jesus and Satan both referred to as the morning star?
• Why does constexpr prevent auto type deduction in this statement?
• Play the Final Fantasy Prelude
• Is there a way to hide/show seams on model?
• Is there a "hard problem of aesthetics?"
• Why is Germany looking to import workers from Kenya, specifically?
• How to react to a rejection based on a single one-line negative review?
• What's the origin of "she's no better than she should be"?
• In The Martian, what does Mitch mean when he is talking to Teddy and says that the space program is not bigger than one person?
• Access and modify attributes of svg markup elements
• Big bang and the horizon problem
• Smallest prime q such that concatenation (p+q)"q is a prime
• Writing in first person for fiction novel, how to portray her inner dialogue and drag it out to make a chapter long enough?
• How to achieve 24t-38t front chainrings
• Terminated employee will not help the company locate its truck
• A continuous analogue of the notion of Hilbert basis
• Fear of getting injured in Judo

At the Human Longevity Lab, studying methods to slow or reverse aging

• Feinberg School of Medicine

The Potocsnak Longevity Institute at Northwestern University Feinberg School of Medicine has launched the Human Longevity Laboratory, a longitudinal,  cross-sectional study that will investigate the relationship between chronological age and biological age across different organ systems and validate interventions that may reverse or slow down the processes of aging.

“The relationship between chronological age (how many years old you are) and biological age (how old your body appears in terms of your overall health), and how they may differ, is key to understanding human longevity,” said Dr. Douglas Vaughan, director of the Potocsnak Longevity Institute. “Knowledge gained from this research may allow scientists to develop methods to slow the process of aging and push back the onset of aging-related disease, hopefully extending the ‘healthspan.’”

Anyone is eligible to participate in the Northwestern research study, but the scientists are focused on studying people who are disadvantaged with respect to biological aging, including those with HIV.

Our primary aim is to find ways to slow down the rate of aging in people that are aging too quickly and provide them with an opportunity to extend their healthspan.”

“We are particularly interested in bringing in people who are at risk for accelerated aging — people with chronic HIV infections, patients with chronic kidney disease, people exposed to toxic substances regularly (smoke and chemicals) and others,” Vaughan said. “Our primary aim is to find ways to slow down the rate of aging in people that are aging too quickly and provide them with an opportunity to extend their healthspan.”

The comprehensive research protocol includes assessments across various systems (cardiovascular, respiratory, neurocognitive, metabolic, and musculoskeletal), and novel molecular profiling of the epigenome. The studies will be performed at no cost to participants at Northwestern Medicine.

Over the next year, the team plans to enroll a diverse cohort representing individuals of all ages, ethnicities and socioeconomic backgrounds to form a picture of how aging affects all members of the population.

A participant’s results will be reviewed with them after their testing is complete. “That is information that might motivate some participants to improve their lifestyle, exercise more, lose weight or change their diet,” said Dr. John Wilkins, associate director of the Human Longevity Laboratory. Wilkins is also an associate professor of medicine in cardiology and of preventive medicine at the Feinberg School of Medicine, as well as a Northwestern Medicine physician.

Ultimately, the Human Longevity Laboratory will launch clinical trials designed to test therapeutics or interventions that might slow the velocity of aging.

View this site for more information on the study.

Dr. Vaughan plans to develop a network of sites duplicating the Human Longevity Laboratory with partners in the U.S. and globally. 

“We hope to clone our laboratory in terms of basic equipment and the protocol,” Vaughan said. “We intend to build a large database that is the most diverse and comprehensive in the world that will contribute significantly to our research.” Potential collaborative partners and sites have already been identified in Asia, Brazil, the Netherlands and in West Africa.

The Human Longevity Laboratory is part of the multi-center Potocsnak Longevity Institute , whose goal is to foster new discoveries and build on Northwestern’s ongoing research in the rapidly advancing science of aging. The Institute is funded by a gift from Chicago industrialist John Potocsnak and family.

“Aging is a primary risk factor for every disease affecting adults — including diabetes, arthritis, dementia, heart disease, diabetes, aging-related cancer, hypertension and frailty,” Vaughan said. “The biological processes that drive aging may be malleable. We think we can slow that process down, delay it, even theoretically reverse it. The curtain is being pulled back on what drives aging. We want to contribute to that larger discovery process.”

Editor’s Picks

Northwestern faculty to speak at TEDxChicago

New biomaterial regrows damaged cartilage in joints, chronicling chicago, one column at a time, related stories.

Should you take a blood test for Alzheimer’s disease?

Northwestern receives $32.4 million to study healthy aging, as we age, we grow more lonely.

Building On The Past: How To Write Previous Studies In Research

Crafting an effective previous study is a foundation for your research. Learn how to write previous studies in research through this guide.

Have you ever wondered how research builds upon itself, creating a foundation for discoveries and insights? Is it wrong if you indulge in working on previous studies in research and get a new idea out of it?

The significance of previous studies in research cannot be underestimated. Every piece of scholarly work, from groundbreaking research to humble literature reviews , contributes to the ever-expanding area of knowledge. 

In this article, we explore the importance of delving into the archives of research, identifying opportunities for further investigation, and ultimately advancing our understanding of the world around us. Let’s get started and understand how to write previous studies in research . 

Purpose And Scope Of Previous Study In Research

The purpose of previous studies in research is to provide a foundation for new investigations. It helps researchers understand what has already been studied, what knowledge gaps exist, and what questions need further exploration. By looking at what others have done, researchers can build on existing knowledge, avoid repeating the same work, and ensure their study contributes something valuable to the field. It also helps validate their research design and methods, making their findings more credible.

The scope of previous studies in research refers to the range of literature and sources that researchers consider relevant to their own study. It involves selecting and reviewing studies that directly relate to their research topic and objectives. Researchers should focus on recent and up-to-date works, including both influential studies and the latest advancements in the field. By being selective and inclusive, they can gain a well-rounded understanding of what has been done before, guiding them to ask meaningful research questions and making their study more impactful.

How To Write Previous Studies In Research

To write the previous studies, you first need to understand the steps in crafting a literature review and the limitations involved. So firstly, let’s understand what is a literature review:

What Is Literature Review?

A literature review is a critical and comprehensive evaluation of existing published research, scholarly articles, books, and other sources relevant to a particular topic or research question. It serves as a crucial component of academic research and helps to establish the context, identify gaps in knowledge, and provide the theoretical framework for the new study. A well-conducted literature review demonstrates the researcher’s familiarity with the existing literature and provides the basis for formulating research objectives and hypotheses.

Also read: What Is A Literature Review? Get The Concept And Start Using It

Literature Review Process

The literature review process typically involves the following steps:

Defining The Research Question

The process starts by clearly defining the research question or topic that the literature review aims to address. A well-defined question helps in narrowing down the search for relevant literature.

Conducting A Comprehensive Search

Researchers then conduct a systematic search for existing literature using academic databases, libraries, online journals, and other reputable sources. Keywords and search terms related to the research question are used to identify relevant studies.

Evaluating The Quality Of Sources

The selected sources are critically evaluated for their quality, credibility, and relevance to the research topic. Researchers consider factors such as the reputation of the authors, the rigor of the research methodology, and the publication venue.

Summarizing And Synthesizing

Researchers summarize the key findings and main points from each selected source. They also identify common themes, trends, and conflicting viewpoints across the literature.

Organizing The Literature

The information gathered from the literature review is organized in a structured manner. Researchers may use themes, categories, or chronological order to present the findings effectively.

Writing The Literature Review

The literature review is then written, incorporating the synthesized information into a coherent narrative. The review should highlight the significance of previous studies, their limitations, and their implications for the new research.

Citing And Referencing

Proper citations and references are provided for all the sources included in the literature review. This ensures academic integrity and acknowledges the work of other researchers.

Also read: Literature Mapping in Scientific Research: A Comprehensive Review

How To Organize And Evaluate Your Literature Review?

Organizing and evaluating sources for your literature review is a crucial process that involves systematically gathering relevant academic materials and assessing their credibility and relevance to your research topic. 

Begin by clearly defining your research question or focus, which will guide your search for appropriate sources. Utilize academic databases, journals, books, and reputable online platforms to gather a diverse range of scholarly materials. 

As you collect sources, categorize them based on their themes, methodologies, or key arguments to facilitate a coherent and logical structure for your literature review. Additionally, critically evaluate each source’s authority, currency, objectivity, and reliability to ensure you include high-quality and trustworthy information in your review. 

By employing a rigorous approach to organizing and evaluating your sources, you will enhance the academic rigor and impact of your literature review.

Limitations Of Previous Studies In Research

The limitations of previous studies are common aspects that researchers should consider while conducting a literature review or developing their own research. These limitations may include:

Sample Size And Representativeness

Some studies may have small sample sizes, which can limit the generalizability of their findings to larger populations or diverse groups. Non-representative samples may also introduce bias into the results .

Research Design And Methodology

Previous studies may have used different research designs or methodologies that could impact the reliability and validity of their results. Flaws in the study design or data collection methods may affect the accuracy of the findings.

Data Quality And Availability

Studies may rely on secondary data sources or data with inherent limitations, potentially affecting the accuracy and completeness of the information used for analysis.

Scope And Generalizability

The scope of a study might be narrow, focusing on a specific population, region, or time period, making it challenging to apply the findings to broader contexts.

Publication Bias

Studies that show statistically significant or positive results may be more likely to get published, while studies with null or non-significant results might go unpublished, leading to a biased representation of the literature.

Ethical Considerations

Ethical issues in data collection or research conduct, such as inadequate informed consent or potential harm to participants, could limit the usefulness or ethical soundness of previous studies.

Related article: What Are The Limitations In Research And How To Write Them?

Identifying Opportunities For Future Research Based On Previous Studies

Identifying opportunities for future research based on previous studies is an essential aspect of conducting a literature review and advancing knowledge in a particular field. Here are some strategies to identify such opportunities:

Unanswered Questions

Look for gaps in the existing literature where important questions remain unanswered or areas where conflicting or inconclusive results have been reported. These gaps represent opportunities for future research to delve deeper into the topic and provide more comprehensive insights.

Emerging Trends

Identify emerging trends or new developments within the field. These can indicate areas that are gaining significance but may not yet have been extensively studied. Exploring these emerging trends can contribute to the cutting edge of research.

Limitations Of Previous Studies

As mentioned earlier, assess the limitations of previous studies. These limitations can point to areas that need further investigation, using improved methodologies or data sources to overcome the shortcomings of earlier research.

Replication Studies

Consider replicating studies that have produced significant findings but have not been replicated by other researchers. Replication studies help validate and strengthen the robustness of existing findings.

Cross-Disciplinary Research

Look for opportunities to integrate knowledge and methodologies from different disciplines. Combining insights from diverse fields can lead to innovative research and fresh perspectives on existing problems.

The Bottom Line

The role of previous studies in research and literature review is crucial in shaping knowledge within any field. Through a comprehensive and critical examination of existing literature, researchers can identify gaps, trends, limitations, and unanswered questions that provide valuable opportunities for future investigation. 

Previous studies serve as a foundation upon which new research can build, validate, and extend existing findings, or challenge established paradigms. By acknowledging and understanding the contributions and limitations of past research, scholars can design more robust studies, explore emerging trends, and engage in cross-disciplinary collaborations to further enrich our understanding of complex phenomena.

Your Creations, Ready Within Minutes!

Are you in a hurry to publish your papers and have no time to create graphs and infographics? Well, we understand that, as a scientist, you have many tasks on your plate but visuals are equally important. Worry not as we are here with a tool that can make your creations ready in minutes – Mind The Graph . Sign Up now to learn more. 

Subscribe to our newsletter

Exclusive high quality content about effective visual communication in science.

Sign Up for Free

Try the best infographic maker and promote your research with scientifically-accurate beautiful figures

no credit card required

About Sowjanya Pedada

Sowjanya is a passionate writer and an avid reader. She holds MBA in Agribusiness Management and now is working as a content writer. She loves to play with words and hopes to make a difference in the world through her writings. Apart from writing, she is interested in reading fiction novels and doing craftwork. She also loves to travel and explore different cuisines and spend time with her family and friends.

Content tags

• University of Wisconsin–Madison

Scandinavian Studies 407/408 - Old Norse

Declensions.

• Noun Declensions
• Verb Conjugations

• << Previous: Home
• Next: Noun Declensions >>
• Last Updated: Sep 18, 2024 1:56 PM
• URL: https://researchguides.library.wisc.edu/OldNorse407

Can Toddlers Help Explain the Origins of Our Bias for Wealth?

The second year of life may be a critical time when children recognize and prefer people who have more resources, new UC Berkeley research shows. Those biases can last a lifetime.

Key takeaways

• Children show a preference for people with more resources at 14 months.
• They also display negative evaluations of people with fewer resources.
• Findings signal that wealth-based biases are more deeply rooted than previously known.

Income and wealth inequality in the U.S. remain  near all-time highs.  Analysts say this disparity is a  “major issue of our time.”  Experts have  spotlighted deep policy failures  fueling the problem and helpful economic fixes to alleviate the suffering. 

Now researchers say our biases favoring the rich over the poor may take root earlier than was previously believed — perhaps when we are very young toddlers.

A  new study  led by a UC Berkeley psychologist suggests that biases for those with more resources can be traced to beliefs formed as young as 14 months. However, researchers say a preference for richer people may not necessarily be driven by kids’ positive evaluations of them. 

Instead, it might be caused by a negative assessment of those with less. 

“Taken together, this suggests that somewhere early in this second year of life — 12 to 15 months of age — we’re really seeing the development of these wealth-based biases come into play,” said Arianne Eason, a UC Berkeley assistant professor of psychology and the paper’s lead author. “And once they come in, they are relatively strong.” 

The  research findings were published this month  in the  Journal of Experimental Psychology: General.

Through a series of seven experiments, the team measured how toddlers demonstrated preferences for people with differing amounts of particular kinds of resources they desired — toys and snacks. Besides a bias toward the more “wealthy” person who had more resources, the children showed dislike and avoidance for those whom researchers labeled in the experiments as the “poorer” individuals.

Together, the results point to the deep-seated ways humans form ideas about what to value. 

The research was partly inspired by Eason’s previous work with children. In graduate school, Eason worked in a lab that studied how infants and children thought resources were and should be distributed. That research consistently demonstrated that young toddlers and preschoolers generally preferred people who distributed resources equally. Wealth-based biases, in contrast, were thought at the time to emerge later in development, perhaps through direct conversations and socialization. 

But Eason increasingly wondered less about how people  distribute  resources and more about how children understood the mere  possession  of them. To find answers, Eason and her collaborators focused on young children at an age when learning about the social world happens rapidly. 

To begin, they needed to determine whether toddlers even retained information about who had more items that were a proxy for “wealth.” They introduced 35 children to two people in a room, both of whom had a clear bowl. One of the bowls was filled with things like toys or snacks; the other was almost empty.

They may have actually had a dispreference for poor people. Arianne Eason, UC Berkeley

Later, each person brought out a new bowl and left the room. This time, though, the bowls were opaque. While the participants couldn’t see how many items were in the bowls — or if there were any toys or snacks at all — they were significantly more likely to select the bowl belonging to the person who had previously had more. It was clear that the young toddlers could retain that information. 

Next, researchers wanted to test what they did with the knowledge and how it factored into deciding who to help when grown-ups had a shortage of resources — in this case, blocks to build a tower. Toddlers were more likely to choose the person who earlier in the study had more resources. That indicated a longer-lasting preference for those individuals who were wealthier. 

Over and over, the children showed that they tracked wealth, preferred to help those who were richer and were more likely to play with those who had more resources. 

The rich kept coming out ahead. 

“It’s very clear that toddlers can track well and have these behavioral preferences in favor of people who have more,” Eason said, adding that the effects were diminished for those younger than about 13 months of age.

The team then tracked the eye movements of the young toddlers as a video played on a screen. An adult on the screen doled out unequal amounts of resources — Legos and crackers, this time. Initially, the children’s gaze was barely different. But then they listened to either a positive recording that said of the adult in the video, “She’s a good girl, she did a good job,” or a negative one that said, “She’s a bad girl, she did a bad job.” 

The ones who heard the positive message spent their time looking equally at the rich and the poor individuals. Meanwhile, those in the negative message group focused more of their attention on the poorer person. 

Just because wealth biases occur in the second year of life doesn’t mean that that has to be the way the world is. Arianne Eason

“It’s not that toddlers had a preference for rich people,” Eason said. “They may have actually had a dispreference for poor people.” 

Eason and her co-authors say their work shows that undoing wealth inequality will require a concentrated effort among adults to change the way young children think about and act toward poorer people. That must happen, they say, with the help of people and institutions in the kids’ lives who can help combat the negative attitudes that children begin noticing around the time they’re learning to walk. 

“These are early-ingrained tendencies,” Eason said. “That means we have to work hard to undo them and put in a lot of concerted effort. But that doesn’t mean we should shy away from it.”

To be sure, part of the wealth-based bias could be linked to evolution, she said. Perhaps humans naturally gravitate toward those with resources that will help keep them alive. 

But Eason said there’s more at play. Her research points to systemic ways we should begin thinking about inequality, and the origin of that wealth-based bias “starting point.” That’s the only way to combat the biases among many adults that benefit the wealthy and perpetuate policies against the poor. 

“Just because wealth biases occur in the second year of life doesn’t mean that that has to be the way the world is,” Eason said. “We are highly flexible as people. We can build policies that go against some of our initial tendencies in order to create the outcomes we want to see.”

• Fierce Pharma
• Fierce Biotech
• Fierce Healthcare
• Fierce Life Sciences Events
• AI and Machine Learning
• Digital Health
• Special Reports
• Special Report
• Awards Gala
• Fierce Events
• Industry Events
• Whitepapers

Walgreens eyes 'tremendous growth' for clinical trials as part of transformation strategy

Walgreens sees a long runway for its two-year-old clinical trials business as it doubles down on its core retail pharmacy operations. 

Ramita Tandon, chief clinical trials officer, shared insights about Walgreens' strategy to ramp up its clinical research capabilities during TD Cowen’s recent 9th Annual FutureHealth Conference FutureHealth Conference FutureHealth Conference.

The retail pharmacy giant says it has reached more than five million patients to potentially recruit into clinical trials since launching the business in June 2022 . The company's clinical trial unit now works with 25 unique customers across biopharma, academic institutions, non-profit and government partners and has signed more than 35 clinical trial contracts. Walgreens has inked partnerships with drugmakers including Freenome, Prothena and Boehringer Ingelheim to use its community pharmacies as clinical trial sites.

The company also recently inked a five-year pact with the Biomedical Advanced Research and Development Authority (BARDA) to boost innovation and access for decentralized clinical trials. The five-year deal means BARDA—part of the U.S. Department of Health and Human Services—will use Walgreen’s clinical trials ecosystem.

The company aims to leverage its national presence, community relationships and data-driven clinical trials solutions to help identify and reach potential study participants for clinical trials. The overall aim is to increase enrollment and diversity in drug development research.

"We launched our clinical trials business in June of 2022 with the idea of just redefining that patient experience and really looking at ways to tackle the issues around lack of patient access and lack of representation that has plagued our industry for a very long time," Tandon told investors during the conference fireside chat. "Our focus has been, 'How do we get access to patients faster? How do we improve the representation in clinical in the drug development process?'"

Walgreens' work in the past two years is "proving out" the value of its assets and capabilities to support pharma partners with clinical research, she said.

"We wanted to design the business model that would look to sort of solve some of the pain points that pharma faces as they think about their R&D portfolio and as they think about their trials. A big part of the pain point is finding patients for trials, getting those trials done in an efficient fashion so they can get to the FDA for approval," she said. "We organized our business model around three key service offerings. The first one is around what we call insights-driven patient recruitment, and that's really accessing the Walgreens direct patient access of 100 million lives and helping pharma to help identify those right patient populations."

Walgreens sits on what Tandon refers to as "a live breathing network" of patients and the company's clinical trials unit can index those patients by race, gender, ethnicity, social determinants of health, even by zip code, she noted.

"We're applying a lot of precision to how we find those patients. Because we're a [HIPAA] covered entity, it allows us to then outreach, which puts us in a very unique position. Not only can we find those patients, we then have the ability to outreach to those patients directly," she added.

Walgreens' patient-level insights enables it to create "more culturally relevant outreach modalities," Tandon noted. "We're using that insight to help us get patients interested in wanting to participate," she said.

The company, which has a footprint of 8,600 retail stores, leverages these locations to help biopharma companies conduct clinical trials.

"We created a flexible set of options, because we know from a trials perspective, trial design, patient populations, the disease conditions, are not all the same. The communities that we serve across Walgreens are not the same, so the way they consume information is not the same," Tandon said.

Many Walgreens' pharmacy locations have private health rooms, "anywhere from 500 square feet to 5,000 square feet, with multiple exam rooms that enables patients to come in and be educated about what a clinical trial is," she said.

"We then take them further in the journey where they can actually have clinical trial services, screening, diagnostics and blood draws. The idea, again, is to be able to tackle the issues around accessibility, because historically, and to some extent today, many patients are unable to get to the academic medical centers or physician practices because they're too far. They can be anywhere from an hour an hour and a half, and that's posing a lot of barriers for broader participation in research," Tandon told investors.

Walgreens also offers hybrid services to use on-site locations while also digitizing aspects of the clinical research workflow.

The company also offers capabilities to take the clinical trial services to a patient's home. "We're actually sending up nurses, study coordinators and other healthcare professionals, while the physicians are able to provide the oversight via telehealth. That flexibility allows our patients opportunities to participate in the drug development process," she said.

Walgreens also offers pharma partners real-world evidence informatics. "That's about tapping into the information that we have on our consumers and patients to help pharma as they think about their evidence generation planning and as they're looking to understand patient populations, treatment regimens, and then also prospectively, as they're looking to collect data on, whether it's qualitative or quantitative, post market," she said.

And Tandon believes there is an enormous market opportunity for Walgreens' clinical research business. The total worldwide R&D spend of pharmaceutical and biotechnology companies is estimated to be $150 billion, according to recent research. The leading 20 global pharmaceutical companies collectively spent $145 billion on R&D in 2023, up 4.5% from 2022, according to Deloitte data.

Data from IQVIA indicates that R&D funding by biopharma companies grew to $72 billion in 2023 , an 18% increase from $61 billion in 2022.

"As we step back and look at the overall addressable market, from the types of outsource services that we're in today, from an R%D perspective is healthy and it's growing. As we think about just the overall R&D investments, it's about $150 billion and 50% of that's being spent in outsourced services. From our perspective, there's tremendous growth for Walgreens to continue down the space and to be able to support pharma and capture these services," Tandon told investors.

The growing clinical trials business is a "big part" of Walgreens' overall strategy, she noted.

"It's about building on the core capabilities of the Walgreens ecosystem and the assets and continue to drive value differentiation for our partners. As we think about the future of clinical trials and where that's heading, certainly, we're going to continue to see the momentum of decentralization of clinical research and getting closer into communities and closer where the patients are," she said. "Walgreens is very uniquely positioned to help support in that momentum. We're going to start to see more improvement in representation in clinical trials and making sure that therapies and new diagnostics are beneficial for all patients across the U.S."

Walgreens is focused on turning around its business and improving its financial performance. The pharmacy chain operator is undergoing a strategic review of its business, including the role of its retail pharmacy stores and its healthcare assets, as company leadership and the board plot the future direction of the company, CEO Tim Wentworth said back in March at the 44th Annual TD Cowen Health Care Conference.

Walgreens went through a massive growth spurt in which it acquired home healthcare business CareCentrix and VillageMD's acquisition of Summit Health-CityMD. 

The company is on track with cost-cutting initiatives that aim to cut $1 billion in expenses this year. That effort also includes slashing capital expenditures by about $600 million. 

Wentworth cautioned investors earlier this year that the company's work to improve its financial performance would not be a "12-month turnaround story."

"This is not a quick story, but I believe that it will be a highly sustained story because the other thing that's very clear to me in every conversation I have is that a large-scale, community-based, engagement-driven, trusted brand has a meaningful role to play in healthcare over the next 20 or 30 years," Wentworth said back in March.

Wentworth seemed bullish about the potential for Walgreens' clinical research recruitment business.

"We're able to recruit diverse patient panels four times faster than pharma can do it themselves. Speed matters when you're doing trials. And, we get paid for it and it's a variable cost business. We hire humans and we use our data to deliver that value to pharma. We aren't buying clinics and building brick-and-mortar do it," Wentworth said. "These sorts of things, while any one of them may not look like it's 10% of our underlying earnings, is highly capital efficient, and two or three of those added together suddenly starts becoming a meaningful part of our growth story."

Improving diversity in clinical research

The Food and Drug Administration (FDA) is taking steps to increase racial and ethnic diversity in clinical trials given that 20% of drugs have a variation in responses across ethnic groups, yet 75% of clinical trial participants are white, while only 11% are Hispanic and fewer than 10% are Black and Asian.

Walgreens is proving out that it can use its community reach to increase patient enrollment as well as racial and ethnic diversity in sponsor-led drug development research. More than 75% of Americans live within five miles of a Walgreens, according to the company.

Walgreens is able to use real-world data insights to recruit a more diverse patient population for clinical trials compared to national benchmarks, executives say.

"From a Walgreens perspective, we're in a very unique position, because we have direct access to diverse patient populations, we're in communities that most are not. It's a natural way to help pharma be able to solve some of those issues. The good news is we're seeing a lot of intentionality behind the design and the operational execution and the need to go after patients and communities that have never been tapped into in the past. It's a big point of differentiation for us as we help support pharma in this effort," Tandon told investors.

Walgreens has published case studies from its most recent clinical research work to highlight its enrollment efforts.

In one Phase 3 vaccine study, Walgreens exceeded the 5,000-referral goal in less than 16 weeks of study start, Tandon noted. The company's efforts to recruit patients also doubled the rate of diverse patient generation. The FDA’s 2020 Drug Trial Snapshot Report identifies an enrollment rate of 8% Black/African American patients and 11% Hispanic/Latino patients for clinical trials. With this study, Walgreens recruited between "15% to 18%" of patients in Black/African American and Hispanic/Latino communities, Tandon noted.

The company's work with Prothena to recruit patients for Alzheimer's drug research also has delivered promising results to increase diversity in clinical research. Walgreens delivered referrals that are 21% Hispanic/Latino for the Alzheimer’s disease study, that's nearly double when compared to the national average of study participation.

"What that's showing is that because we have access to diverse patient populations, we have the ability to quickly identify those patients and be able to match those patients to trials faster than you know what the industry's been able to do so far," Tandon said.

• Weird But True
• Sex & Relationships
• Viral Trends
• Human Interest
• Fashion & Beauty
• Food & Drink

trending now in Lifestyle

NASA issues alert for fast-moving, stadium-sized asteroid...

I’m a flight attendant — travelers should never do this with...

I modernized my grandma's vintage wedding dress for my own big...

Conservatives and liberals have different brain structures —...

Do penises shrink with age? Study reveals answer to age-old...

I'm a dentist— don’t eat during these two hours of the day if...

'Glossing' bosses are the toxic workplace trend ruining employee...

The 5 most rat-infested cities in America revealed — sorry, New...

Do penises shrink with age study reveals answer to age-old question.

A medical expert has finally answered the question that has plagued “most men”: can your penis actually shrink?

Sure, there are arguably bigger things in the world to worry about, but apparently that hasn’t stopped the male species from fretting about their manhoods for far too long.

While it’s not technically possible for penises to dramatically reduce, it turns out there are a string of different factors that can affects a man’s erection result, making it smaller than it once was during times of performance.

Mary Samplaski, MD, urologist and the director of male infertility at the University of Southern California, said warned a man’s age and lifestyle choices could have a negative effect on a penis’ ability to maintain a consistent level of tumescence.

Tumescence is the medical term that refers to the normal engorgement with blood of the erectile tissues, marking sexual excitation, and possible readiness for sexual activity.

“There’s not really a medical tool for measuring penis shrinkage,” says Dr. Samplaski told  Men’s Health .

“What we do know is that smoking and age can cause a decline in testosterone production.”

Studies  show smoking can damage the blood vessels and hinder proper blood flow – which in turn can have a knock-on effect on erections.

While doctors don’t fully understand the connection between testosterone and erectile dysfunction,  research  suggests that a decline in testosterone can affect the strength of erections.

Dr. Samplaski also said that conditions such as cardiac disease, diabetes, or thyroid issues can cause changes in erectile strength.

Obesity can be another culprit. Dr. Samplaski explained that fat contains an enzyme that converts testosterone into oestrogen, which can cause erectile issues and testicular shrinkage.

“Exercise is a natural means of achieving a rise in a man’s testosterone. Testosterone is important for the health and wellbeing of the male functional organs,” she told the publication.

Start and end your day informed with our newsletters

Morning Report and Evening Update: Your source for today's top stories

Thanks for signing up!

Please provide a valid email address.

By clicking above you agree to the Terms of Use and Privacy Policy .

Never miss a story.

Bizarrely, having “too much” sex is also cited as being able to decrease the size of a man’s junk over time as excessive sexual activity can lead to injuries, which could cause a build-up of scar tissue.

However, despite the potential for loss in size, penis shrinkage is incredibly rare, medical experts warn.

It comes 18 months after it was found that the  average penis length has increased by 24 per cent  over the past 30 years.

This may sound like good news, but researchers behind the study published in the World Journal of Men’s Health last year warned it’s actually a “concerning” discovery.

“Any overall change in development is concerning, because our reproductive system is one of the most important pieces of human biology,” Dr. Michael Eisenberg, the study’s author, told Stanford Medicine’s blog  Scope  at the time.

“If we’re seeing this fast of a change, it means that something powerful is happening to our bodies.”

The alarming data was obtained from 75 studies conducted with over 55,000 men between 1992 to 2021 which analysed the length of an erect penis.

“Erect penile length is getting longer, from an average of 4.8 inches (12.1cm) to 6 inches (15.2cm), over the past 29 years,” Dr. Eisenberg said.

More research is needed to confirm the findings and “determine the cause” of the changes.

Advertisement

• Become a member

Impaired Balance Predicts Cardiovascular Disease in 70‐Year‐Old Individuals—An Observational Study From the Healthy Aging Initiative

Information & authors, metrics & citations, view options, methods and results, conclusions, nonstandard abbreviations and acronyms, clinical perspective, what is new, what are the clinical implications, study design and setting, participant recruitment.

Balance Assessment

Ethics and approval, statistical analysis.

Baseline Characteristics

Incidence of Cardiovascular Disease During Follow‐Up

Additional Analyses

Conclusions, sources of funding, disclosures, eletters (0).

eLetters should relate to an article recently published in the journal and are not a forum for providing unpublished data. Comments are reviewed for appropriate use of tone and language. Comments are not peer-reviewed. Acceptable comments are posted to the journal website only. Comments are not published in an issue and are not indexed in PubMed. Comments should be no longer than 500 words and will only be posted online. References are limited to 10. Authors of the article cited in the comment will be invited to reply, as appropriate.

Comments and feedback on AHA/ASA Scientific Statements and Guidelines should be directed to the AHA/ASA Manuscript Oversight Committee via its Correspondence page.

Information

Published in.

Permissions

• cardiovascular disease
• risk factor
• Cardiovascular Disease

Affiliations

Funding information.

If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Select your manager software from the list below and click Download.

View options

Pdf and all supplements, login options.

Check if you have access through your login credentials or your institution to get full access on this article.

Purchase Options

Purchase this article to access the full text.

Purchase access to this article for 24 hours

Restore your content access

Enter your email address to restore your content access:

Note: This functionality works only for purchases done as a guest. If you already have an account, log in to access the content to which you are entitled.

Share article link

Copying failed.

Submit a Response to This Article

Compose eletter, contributors, statement of competing interests, previous article, next article, comment response.

• About the Hub
• Announcements
• Faculty Experts Guide
• Subscribe to the newsletter

Explore by Topic

• Arts+Culture
• Politics+Society
• Science+Technology
• Student Life
• University News
• Voices+Opinion
• About Hub at Work
• Gazette Archive
• Benefits+Perks
• Health+Well-Being
• Current Issue
• About the Magazine
• Past Issues
• Support Johns Hopkins Magazine
• Subscribe to the Magazine

You are using an outdated browser. Please upgrade your browser to improve your experience.

Healthy volunteers needed for cannabis and alcohol research

By Hub staff report

Healthy adults age 21-55 are needed to take part in a Johns Hopkins research study. The study will require nine total visits to the lab, located at Johns Hopkins Bayview Medical Center.

Participants will first complete an in-person screening session (occurs over two days) to determine study eligibility. Participants who are eligible and agree to be in the study will complete seven drug administration sessions, each lasting about 10 hours. In these sessions, participants will eat a brownie that contains cannabis and consume alcohol and then complete various tests to measure different aspects of performance.

Those who complete the study can earn up to $2,660.

Call 410-550-0050 for details. You can also click on this link to see if you may be eligible.

Principal Investigator: Tory Spindle, PhD IRB00290015

News Network

• Johns Hopkins Magazine
• Get Email Updates
• Submit an Announcement
• Submit an Event
• Privacy Statement
• Accessibility

Discover JHU

• About the University
• Schools & Divisions
• Academic Programs
• Plan a Visit
• my.JohnsHopkins.edu
• © 2024 Johns Hopkins University . All rights reserved.
• University Communications
• 3910 Keswick Rd., Suite N2600, Baltimore, MD
• X Facebook LinkedIn YouTube Instagram

An official website of the United States government

The .gov means it’s official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

• Publications
• Account settings

The PMC website is updating on October 15, 2024. Learn More or Try it out now .

• Advanced Search
• Journal List
• Gerontol Geriatr Med
• v.8; Jan-Dec 2022

Ageism and Psychological Well-Being Among Older Adults: A Systematic Review

1 Department of Social Work, George Mason University, Fairfax, VA, USA

2 National Rehabilitation Research and Training (RRT) Center on Family Support, University of Pittsburgh, Pittsburgh, PA, USA

Ageism may have harmful effects on the psychological well-being of older adults, leading to mental health issues, such as depression and anxiety. However, there are insufficient data to establish this hypothesis, and most work on the subject has appeared only in the form of conceptual or theoretical papers. This study reviewed quantitative studies of the relationship between ageism and psychological well-being of older adults. We conducted a comprehensive review using searches of academic databases, the grey literature, hand searches, and reference mining. A total of thirteen articles were selected using the inclusion criteria. All the reviewed studies showed a negative association between ageism and the psychological well-being of older adults. The study confirmed a negative association between ageism and older adults’ psychological well-being, finding that older adults with a high level of psychological well-being may be less negatively affected by ageism, especially those who were proud of their age group, experienced less negative emotions, were more optimistic about aging and their future, were more self-confident about their bodies, and were flexible in setting goals. The identified mediators of the association can inform intervention development to the effects of ageism and improve older adults’ psychological well-being.

Introduction

Growing older involves gaining maturity and becoming a more responsible and respectful adult. The process of aging can be viewed unfavorably by some people, who view it pessimistically, and this reduces the pleasure they may have gained from their own growth ( Kang, 2020 ). Aging is often considered to be a challenging process, during which individuals lose their confidence and experience a loss of productivity ( Schafer & Shippee, 2009 ). Significant declines in social and cultural status have been observed in older adults over the past century as a result of industrialization and modernization ( Aboderin, 2004 ; Nelson, 2005 ). The industrial age and technological advancements have increased the need for people to work efficiently and quickly to remain competitive ( Tuomi et al., 1997 ). These changes have had the effect of decreasing the need for and visibility of older adults’ activities ( Solem, 2005 ).

A growing body of research has observed an increase in negative attitudes toward older individuals over the years ( Nelson, 2005 ; Scharlach et al., 2000 ). Several studies have shown that members of the younger generations now exhibit more negative views and attitudes toward older adults than was previously the case ( North & Fiske, 2012 ). Negative beliefs and attitudes towards older adults are increasingly prevalent, which may add to the barriers that older adults face when seeking employment ( Skirbekk, 2004 ). Consequently, older adults are often considered to be merely passive recipients of welfare, and they may even be accused of being a burden to younger generations ( Hudson, 2012 ). The belief that older adults are less valuable or of no interest to society may contribute to ageism.

Ageism is stereotyping, prejudice, and discriminatory actions or attitudes based on chronological age ( Iversen et al., 2009 ). Ageism, therefore, can be operationalized as stereotypes, prejudices, and discrimination, and each of those components, individually, can be seen as cognitive, affective, and behavioral ( Iversen et al., 2009 ). Consequently, age stereotypes are fixed beliefs that overgeneralize the characteristics, attributes, and behaviors held in common by a particular group ( Whitley & Kite, 2006 ). Age stereotypes can contribute to assumptions about a person’s physical and mental capabilities, social skills, political and religious beliefs, and other traits based on their age ( World Health Organization, 2021 ). A prejudice is a negative or positive emotional reaction to a person based on their perceived affiliation with a particular group ( World Health Organization, 2021 ). Age prejudice is one of the most socially vocalized and institutionalized prejudices in many segments of society, and it is disregarded in numerous aspects of social life ( Nelson, 2005 ). A discriminatory act is characterized primarily by distorted behavior that treats individuals in a non-constructive manner ( Dovidio et al., 2011 ). Age discrimination is behavior directed at people based on their age, including actions, practices, and policies ( World Health Organization, 2021 ).

Ageism is a very serious issue. While it can theoretically be directed toward any age group, the vast majority of studies focus on older adults or late adolescents ( Nelson, 2005 ). Although ageism can be shown in terms of positive stereotypes or attitudes, it is most closely associated with negative stereotypes or attitudes ( Palmore, 1999 ). Ageism can manifest in two main ways: implicitly, through unconscious thoughts, feelings, and behaviors, or explicitly, through intentional actions or verbal expressions triggered by conscious awareness ( Iversen et al., 2009 ). Furthermore, ageism is not restricted to directed toward others but can also be self-directed ( Ayalon & Tesch-römer, 2017 ). Exposure to ageism over time can result in the internalization of ageist attitudes and stereotypes, as described by Levy (2009) in stereotype embodiment theory. Many older adults tend to internalize the negative stereotypes of ageism that continue to be perpetuated throughout society today and tend to confine themselves to age-related stereotypes, becoming weak, unhealthy, and even less able to accept new learning opportunities ( Streb et al., 2008 ).

Internalized age stereotypes may lead to low levels of self-esteem and self-confidence ( Orth et al., 2010 ), and it may affect older adults’ health negatively ( Emile et al., 2014 ), especially with regard to their mental health and well-being ( Bryant et al., 2012 ). An individual who believes that they are too old may be more susceptible to the negative consequences of ageism, which may include decreased self-efficacy and increased negative emotions ( Eibach et al., 2010 ). The converse may also be true, as positive perceptions and attitudes on aging may have beneficial effects on psychological well-being ( Bryant et al., 2012 ). Older adults who have experienced discrimination based upon their chronological age may be more exposed to stressors ( Snape & Redman, 2003 ) and depression ( Tougas et al., 2004 ), which are detrimental to their mental health ( Pascoe & Richman, 2009 ).

Ageism is increasingly recognized as a risk factor associated with increased stress, anxiety, depression, and lowered life satisfaction ( Ayalon et al., 2019 ). However, articles on ageism generally take the form of conceptual or theoretical papers, and they tend to center on identifying the causes and consequences of ageism ( Iversen et al., 2009 ). More empirical studies are needed to investigate the harm that ageism can cause to the psychological well-being of older adults. Our review examined this relationship by synthesizing the results of several studies identified in a thorough systematic search.

Purpose of the Review

This systematic review examines how the experience of ageism experience among older adults influences their psychological well-being. This study also seeks insight into successful aging by identifying factors that mediate or moderate the relationship of ageism to psychological well-being. Our overarching goal is to mitigate or eliminate the adverse effects of ageism, especially on the psychological well-being of older adults. Using a systematic review method allows the researcher to comprehensively identify relevant literature through transparent and rigorous processes ( Littell et al., 2008 ). Several systematic reviews have examined ageism and its effects on older adults: these include assessments of how stereotypes of aging affect memory and cognitive performance ( Lamont et al., 2015 ), ageism’s broad effects, and theories that explain ageism ( North & Fiske, 2012 ). However, no research has hitherto examined the direct effects of ageism on older adults’ psychological well-being.

A new paradigm for understanding the aging society is necessary in the face of a rapidly expanding population of older adults to assess these developments in a long-term perspective. The study of ageism can be a key foundational resource for older adults. Unbiased summaries of quantitative outcome studies from our systematic review may help to develop an understanding of the potential risks of ageism on psychological well-being. Furthermore, the mediators and moderators identified between ageism and the psychological well-being of older adults will support future policy and practices.

We aimed to locate all empirical evidence that examined the relationship between ageism and older adults’ psychological well-being through a comprehensive and unbiased search. The systematic review methodology was guided by two sources: Systematic Reviews from the Centre for Reviews and Dissemination (2009) and Systematic Reviews and Meta-Analysis from Littell et al. (2008) . We also followed the guidelines from a review protocol, the PRISMA 2020 statement (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) developed by Page et al. (2021) , to verify the validity of the steps involved in the systematic review. PRISMA is a set of standards that includes a 27-item checklist and a four-phase flow diagram describing how systematic reviews should be reported ( Page et al., 2021 ). The completed PRISMA checklist was included in Appendix B . A critical appraisal checklist for analytical cross-sectional studies developed by the Joanna Briggs Institute (JBI) was used to assess the methodological quality of the reviewed studies ( Moola et al., 2020 ). Additionally, we reported our results using Pleasant et al.'s (2020) study as a guide ( Pleasant et al., 2020 ). Our first step was to develop a search strategy to guide a thorough but rigorous systematic search by refining our research question. We also articulated and tested our complete set of search terms to decrease our chances of missing relevant literature. A number of inclusion and exclusion criteria were set to prevent bias in the selection process. We used a wide range of sources for our review, including several electronic databases, grey literature, hand searches, and reference mining.

Criteria for Considering Studies for the Review

Studies included in this review focused on the psychological well-being of older adults who have experienced discrimination based on their age. Studies had to meet several criteria to be eligible for inclusion in this review. For ensuring comprehensive and unbiased literature searches, the PICOS (Population, Intervention, Comparison, Outcomes, and Study design) framework was used to formulate literature search strategies ( Table 1 ). The population of interest for the systematic review was older adults aged 60 and above. Our rationale behind selecting this age range was based on retirement age. The retirement age varies around the world, and it is expected to increase along with increased life expectancy ( Forman & Chen, 2008 ). We adopted an average retirement age range from the Organization for Economic Co-operation and Development’s (OECD) countries from statistics on the average retirement age ( OECD, 2015 ). The normal retirement age of OECD countries in 2014 ranges from 60 (Luxembourg) to 67 (Iceland) ( OECD, 2015 ).

PICOS Framework for Systematic Review.

The review included studies that measured ageism or attitudes towards older adults. Ageism can be direct or indirect, and it tends to be reproduced and unconsciously reflected in social or cultural spheres ( Iversen et al., 2009 ). While ageism toward older adults might also be demonstrated in a positive stereotype or attitudes toward them ( Palmore, 1999 ), ageism in this study was confined to only negative attitudes and feelings. Furthermore, we included studies on self-directed ageism, which refers to ageism directed at oneself, in order to examine how internalized age stereotypes affect older adults’ psychological well-being. The large number of words associated with ageism prompted us to choose broad and general search terms in order to avoid the omission of relevant articles and to identify all potentially relevant studies.

In this study, the psychological well-being of older adults was the outcome of interest. Psychological well-being is a multi-dimensional concept determined by multiple components and factors ( Kim et al., 2017 ). We adopted a broader definition of psychological well-being as suggested by Diener et al. (2017) . They conceptualized psychological well-being as an all-inclusive term that includes desirable psychological characteristics as well as subjective well-being; that is, the subjective perception of life that an individual experiences in their environment ( Baker et al., 2005 ). Psychological well-being is a key indicator for measuring the subjective aspects of quality of life ( Baker et al., 2005 ). Further, it is an integrative construct that includes diverse affective and cognitive dimensions, such as life satisfaction, positive/negative affect, mental health, self-actualization, optimal functioning, happiness, and mood ( Levin & Chatters, 1998 ; Ryff, 1989 ). Depression, life satisfaction, stress, and other mental health behaviors were also considered in measuring psychological well-being. Study designs were limited to empirical quantitative studies that used statistical, rather than descriptive, analysis to present findings. Studies that met this population, predictor, outcome, and type of study criteria were eligible for review consideration.

To summarize, ageism literature was systematically reviewed using the following criteria: (a) focused solely on ageism without any other forms of discrimination; (b) measured ageism against older adults (60 years old and above); (c) examined the relationship between ageism and psychological well-being; (d) was written in English; and (e) used a quantitative design. Studies were excluded that (a) identified other sources of discrimination such as disability, race, sexuality, HIV, LGBTQ (lesbian, gay, bisexual, transgender, and questioning), and mental illness; (b) examined the relationship between ageism and physical health without psychological well-being; (c) used ageism as an outcome variable; and (d) used a literature review and qualitative design as the research method.

Search Strategy

To identify and determine all published research studies on ageism focusing on the influence on older adults’ psychological well-being, we conducted a comprehensive search to identify all potentially relevant literature from the inception of each index to August 31, 2019, both published and unpublished. We searched relevant resources regardless of the country of origin but only included resources written in English. In order to find all potential studies, we established four search strategies: database searches, grey literature searches, hand searches of selected journals, and reference mining. We used three bibliographic databases: ProQuest Research Library , Web of Science , and Academic Search Complete for our literature search. The search included all literature from the earliest years that the databases cover to August 31, 2019. The set of search terms included Ageism (or ageist), older adults (or aged or the elderly), and psychological (or emotional) well-being (or health or satisfaction). Various combinations of terms were tested to identify all potentially relevant studies, and our final search terms used for each database were provided in Appendix A .

To find possible unpublished literature on our topic, we visited websites of state/national government agencies, research centers, and both profit/nonprofit organizations that were most relevant to our topic and selection criteria. The grey literature sites included Cochrane Library , ProQuest Dissertations & Theses , American Psychological Association (APA) , American Society on Aging (ASA) , National Center on Elder Abuse (NCEA) , National Committee for the Prevention of Elder Abuse (NCPEA) , and The Fiske Lab. A general web search located additional studies through google and google scholar .

Four journals that were highly relevant to the search criteria were selected for a hand search to supplement unidentified literature that might have been missed through an electronic search: Ageing and Society (1981–present), Aging and Mental Health (1997–present), Gerontologist (1961–present), and Psychology and Aging (1986–present). We searched the entire contents of the four journals to find potentially eligible studies. Backward reviews through a reverse bibliographic search were also included for the hand search. Furthermore, we scanned the relevant references from articles identified through previous search methods to identify additional literature that met the search criteria.

Data Collection and Analysis Methods

We used EndNote X9, a reference managing computer program, for data collection processes, including downloading results of electronic searches, organizing downloaded references, checking duplication, and locating full texts. The data collection process started by first retrieving abstracts or titles for all resources through the search process. The second screening process involved reviewing full texts of the initially screened resources to determine if the sources were relevant by applying exclusion and inclusion criteria. For reliability of quality assessment and data extraction, all screening processes were undertaken by both the first author and the second author. Disagreements about screening and full-text retrieval decisions were discussed until reaching a consensus.

After the full-text review, final resources were selected for data extraction. The first author collected data from the final resources, and the second author checked and revised the data extraction by the first author and supplemented insufficient data, if needed. Disagreements among the two authors were again resolved by consensus to establish inter-rater reliability in the data extraction process. The data collection included (a) Study design: overarching goal, study site and control variables, (b) Methodology: type of data, data collection methods and statistical techniques, (c) Sample: random sampling, sample size, and sample characteristics (age, education level, race/ethnicity, (d) Predictor (ageism): data source, measures, tools used, information regarding the validity of tools, (e) Outcome (psychological well-being): data source, list of outcomes assessed, measures, tools used, information regarding the validity of tools, (f) Findings: the relationship between ageism and psychological well-being (statistically significant associated or not associated), and (g) Intervention: interventions between ageism and psychological well-being (statistically significant associated or not associated). Finally, to establish the study quality standards, information regarding (a) Internal validity (missing data and reliability and/or validity of variables) and (b) External validity (representative of the population) were extracted

Figure 1 illustrates the search process. The database search identified 6103 records, while additional 314 records were identified from other sources. 673 duplicates were removed from the initial sample ( n = 6417). A screening of the remaining records’ titles and abstracts ( n = 5744) was conducted to ascertain eligibility criteria, which led to the exclusion of ( n = 5447) records. All of the remaining articles ( n = 297) were evaluated by full-text review, and 284 articles were excluded for the reasons outlined in Figure 1 . Thirteen articles were ultimately selected for data extraction.

Systematic review flow diagram.

Studies’ Design and Setting

All thirteen studies examined the relationship between ageism and the psychological well-being among older adults aged 60 and above. Table 2 shows a summary of the study design and setting of thirteen studies. 38% ( n = 5/13) proposed and tested interventions that buffer the relationship between ageism and psychological well-being. 31% ( n = 4/13) adopted conceptual frameworks to explain and verify the association between ageism and psychological health. Stereotype internalization theory ( Bai et al., 2016 ), stress process model ( Kim, 2015 ), minority stress theory ( Lyons et al., 2018 ), and stereotype embodiment theory ( Zhang et al., 2019 ) were used as theoretical grounds to support the ageism and psychological health link.

Study Design and Setting.

1 IADL: Instrumental Activities of Daily Living.

38% ( n = 5/13) were conducted in the US and 46% ( n = 6/13) in Asia. There was one study conducted in Europe, and the other in Germany, Mexico, and Spain. 38% ( n = 5/13) conducted a secondary analysis of existing data, and the samples in these studies were selected through a probability sample design. 15% ( n = 2/13) were longitudinal panel research, whereas all the other studies were cross-sectional design. Except for one PhD dissertation ( Kim, 2015 ), all other studies (92%) were published in peer-reviewed journals and were published between 2004 and 2019.

Studies’ Participants

Table 3 provides a summary of the 13 studies included in this review, along with each of their participants’ characteristics. The number of participants in the studies varied considerably, from 60 in a non-random sampling setting ( Garstka et al., 2004 ) to 3991 in an RCT that drew from a nationally representative survey ( Kim, 2015 ). All of the participants in the reviewed studies were older adults aged 60 years and older. The lowest mean age was 62.49, while the highest one was 77.4. Lee and Kim (2016) and Sabik (2013) included women only, while the other studies included men and women.

Sample Characteristics.

Measurement

38% ( n = 5/13) used established scales that have been used and evaluated. Three studies used Palmore’s (1999 , 2001) ageism scale ( Kim et al., 2015 ; Lee & Kim, 2016 ; Lyons et al., 2018 ). Zhang et al. (2018) and Zhang et al. (2018) used the Image of Aging Scale developed by Levy et al.(2004) . 62% ( n = 8/13) used non-validated measures or developed their scales to measure ageism. Avidor et al. (2017) , Kim (2015) , and Shin et al. (2018) used a dichotomous variable to measure age-based discriminations. Bai et al. (2016) used a measure of perceptions of aging as a burden to examine the self-directed ageism of older adults. Fernandez-Ballesteros et al. (2017) used three questions with a 4-point Likert-type scale to measure negatively perceived age discrimination. Garstka et al. (2004) measured ageism through four different items: victims of age discrimination as an individual, age group victimized by society according to age, deprivation of opportunities, and discrimination due to old age. Siguaw et al. (2017) used four items that were developed by Garstka et al. (2004) . Sabik (2013) used five questions to assess ageism: individual/age group deprivation of opportunities, exclusion from many sectors of public life, considered to be worthless after retirement, achievements not properly appreciated because of chronological old age. All measures of ageism in the included studies provided Cronbach’s alpha, and 85% ( n = 11/13) were above .75.

Psychological Well-being

92% ( n = 11/13) used validated outcome measures to evaluate older adults’ psychological well-being. Reviewed studies measured psychological well-being with different measurement instruments such as depression, subjective well-being through life satisfaction, and mental health. The outcome variable for 54% of the studies ( n = 7/13) was depression. 38% ( n = 5/13) used the concept of subject well-being by measuring life satisfaction. Ballesteros et al.’ s (2017) study included a life satisfaction measure as a component of measuring active aging. Garstka et al. (2004) assessed self-esteem in addition to life satisfaction as outcome measures. Sabik (2013) used the 5-item Mental Health subscale from the MOS 36-Item Short-Form Health Survey, which assesses general mental health and well-being. Cronbach’s alphas of all the measures of psychological well-being in the included studies were all above. Seventy-seven except the life satisfaction measure (Cronbach’s α: 0.57) of Garstka et al. (2004) .

Relationship between Ageism and Psychological Well-being

All of the studies indicated that an increase in experiences of ageism was a statistically significant predictor of decreased psychological well-being in older adults ( Table 4 ). 62% ( n = 8/13) examined ageism as a predictor that influences the psychological well-being of older adults through the regression analysis. All regressions include many control variables such as sociodemographic, socioeconomic, and physical health status. 38% ( n = 5/13) conducted structural equation modeling tests to look at direct or indirect effects of ageism.

Summary of Results (Relationship between Ageism and Psychological Well-being).

1 T1: Time 1, 2008; T2: Time 2, 2011

2 GDS: Geriatric Depression Scale.

3 CES-D: Center for Epidemiologic Studies Depression.

4 MOS: Medical Outcomes Study.

5 SWL: The Satisfaction with Life Scale.

6 PAS: Positive Age Stereotypes.

7 NAS: Negative Age Stereotypes.

Depression was an outcome assessed in 54% ( n = 7/13). An increase in experiences or perceptions of ageism (or age discrimination) was associated with an increase in depressive symptoms as well as stress and anxiety. The study by Lyons et al. (2017) showed that ageism experience is significantly related to the prevalence of stress and anxiety disorders, as well as depression. In Lee and Kim’s (2016) study, ageism was found to affect stress directly and had an indirect effect on depression through stress. Zhang et al. (2019) indicated that negative age stereotypes were associated with higher levels of depression and loneliness and lower morale.

Life satisfaction was included as an outcome measure in 38% of the total studies ( n = 5/13). The results of these studies indicated that perceived ageism and ageism experience was negatively associated with life satisfaction. The study by Fernandez-Ballesteros et al. (2017) found that perceived ageism negatively affects active aging, which includes life satisfaction, subjective health, and self-perceptions of aging. Garstka et al. (2004) showed a direct negative effect of age discrimination on self-esteem as well as life satisfaction. Lastly, Sabik’s (2013) study indicated that perceived age discrimination is negatively associated with general mental health and well-being.

Interventions Between Ageism and Psychological Well-being

38% ( n = 5/13) proposed and tested mediating and moderating variables between ageism and older adults’ psychological well-being ( Table 5 ). Garstka et al. (2004) examined the mediating effect of age group identification, which refers to an individual’s internal perception of their own age group. It was based on the rejection–identification theory, which suggests that perceived discrimination deteriorates the psychological well-being in low-status groups, but that group identification partially alleviated this effect. Age group identification attenuated the negative effect of ageism on well-being. The total effect of ageism on the psychological well-being decreased ( β = −.36, p < .05) compared to its direct effect ( β = −.54, p < .05).

Summary of Results (Interventions between Ageism and Psychological Well-being).

1 NAS: Negative Age Stereotypes.

2 PAS: Positive Age Stereotypes.

3 FGA: Flexible Goal Adjustment.

Kim (2015) tested the mediating effects of self-perception of aging and purpose in life on the relationship between ageism and depression. The overall indirect effect of ageism on depression mediated by self-perception of aging and purpose in life was statistically significant ( β = .124, p < .001). The mediating effect of self-perception of aging ( β = .112, p < .001) was larger than that of purpose in life ( β = .012, p = .048).

Kim et al. (2015) examined the mediating effect of emotional reactions and the moderating effect of coping responses. The duration of many negative emotional reactions was examined, including being hurt, angry, frustrated, humiliated, discouraged, terrified, foolish, or ashamed. Coping responses included problem-focused responses such as formal action, confrontation, and seeking support, and emotion-focused such as passive acceptance and emotional discharge. Although the results did not confirm the moderating effect of coping responses, the effect of ageism on depression ( β = −.01, p > 0.05) was no more statistically significant after adding emotional reactions.

Sabik (2013) tested the mediating effect of body esteem on the relationship between ageism and the psychological well-being of older adults. Sabik assumed that a high level of body esteem might mediate the association between ageism and psychological well-being. The results suggested that body esteem partially mediated the association (indirect effect: β = −0.047, p < .05); that is, the effect of ageism on psychological well-being was decreased from −.29 ( β , p < .001) to −.24 ( β , p < .001).

Lastly, Zhang et al. (2018) examined a moderating role of flexible goal adjustment (FGA) between age stereotypes and the well-being of older adults. FGA implies that individuals pursue their own personal goals, disengaging from goals that are incompatible with their preferences and altering their goals in response to unique conditions. Zhang et al. (2018) found that the interaction term, including FGA, was significant in predicting well-being ( β = .19, p < .01). Negative age stereotypes decreased the positive effect of positive age stereotypes on well-being for older adults with low FGA conditions, but the effect remained the same for individuals with high FGA.

Methodological Quality

Methodological quality was assessed using the JBI’s checklists. Table 6 presents a summary of the methodological qualities of the articles we reviewed. A total of eight methodological qualities were examined to assess the possibility of bias in the design, conduct, and analysis of reviewed studies. An inter-rater review process was implemented between two co-authors to assess the methodological quality of the reviewed studies. The total score of the Methodological qualities ranged from 0 to 8. Our reviewed articles ( N = 13) scored between 3 and 8, with mean scores of 6.1 ( SD = 1.3) and a median score of 7. Kim et al.’s (2015) study received all eight points, whereas Siguaw et al.’s (2017) study received three points. All studies met two of the criteria (b and h). All articles provided a clear explanation of how the study participants were selected or recruited. Additionally, the methods section was sufficiently detailed to enable us to identify the analytical techniques utilized. However, only 38% ( n = 5/13) successfully measured ageism in a valid and reliable manner.

Review of Methodological Quality.

a Were the criteria for inclusion in the sample clearly defined?

b Were the study subjects and the setting described in detail?

c Was the exposure measured in a valid and reliable way?

d Were objective, standard criteria used for measurement of the condition?

e Were confounding factors identified?

f Were strategies to deal with confounding factors stated?

g Were the outcomes measured in a valid and reliable way?

h Was appropriate statistical analysis used?

*Y: Yes; N: No; U: Unclear; N/A: Not applicable.

The first goal of this study was to locate studies that examined the relationship between ageism and older adults’ psychological well-being. A total of 13 studies were identified through a comprehensive search, and all of them empirically showed the negative effects of ageism on the psychological well-being of older adults. That is, older adults who perceived or experienced ageism were more likely to show lower levels of psychological well-being than those who did not perceive or experience ageism. Moreover, the psychological well-being of older people was adversely affected if they held internalized ageist thoughts.

The second goal of the study was to identify mediating or moderating factors between ageism and the psychological well-being of older adults. Five of the reviewed studies tested mediating or moderating effects of interventions between ageism and psychological well-being. Except for the coping responses, all mediating variables buffered the negative effects of ageism on psychological well-being in older adults. Age group identification ( Garstka et al., 2004 ), emotional reactions ( Kim et al., 2015 ), self-perception of aging and purpose in life ( Kim, 2015 ), body esteem ( Sabik, 2015 ), and flexible goal adjustment ( Zhang et al., 2018 ) were all identified as effective mediators to mitigate the negative effects of ageism on the psychological well-being.

To briefly synthesize the interventions, the psychological well-being of older adults (1) who were proud to be a member of their age group, (2) who experienced less negative emotions (i.e., feeling hurt, angry, sad, frustrated, humiliated, discouraged, terrified, foolish, or ashamed), (3) who considered aging process positively and held a positive view of their future, (4) who had greater body esteem, and (5) who had high levels of flexible goal adjustment were less negatively influenced by ageism. These mediators can inform intervention developments that will lessen the effects of ageism and improve older adults’ psychological well-being.

Scholars who investigate the extent of the detrimental impacts of ageism on older adults have focused on developing effective interventions in recent years ( Bujang, Sa’at, & Bakar, 2017 ). For instance, Burnes et al.’s (2019) systematic review of interventions to reduce ageism against older adults found that aging education toward young people and intergenerational contact were effective approaches for adolescents and young adults. However, it remains a question whether education and intergenerational contact can fully reduce the effects of ageism on older adults. In addition, during the COVID-19 pandemic, maintaining contact between generations has been an increasingly challenging endeavor. Thus, it is important to discuss how the negative effects of ageism among older adults during the pandemic. We believe that the intervention results of our study can be used as a basis for implementing innovative strategies to reduce ageism’s pernicious effects among older adults during periods of social distancing. These effects may result in a necessity for effective interventions in older adults, such as education for positive aging, emotional management, boosting body confidence, and flexible goal setting that may serve as downstream factors to mitigate or perhaps reverse negative effects of ageism on their psychological well-being. Our review also provides theoretical frameworks that enable a deeper understanding of the role of ageism in psychological well-being. One of these is the stress process model ( Kim, 2015 ). Recurrent experiences of ageism can be a stressor, and exposure to these stressful events could lead to depressive symptoms ( Kim, 2015 ). Unlike other stressors, ageism cannot be resolved only at the individual level. All age groups should be involved in addressing issues regarding ageism because it is one of the most socially condoned and institutionalized forms of prejudice that is reflected in many areas of society ( Nelson, 2005 ). The stereotype embodiment framework also helps us understand how ageism inhibits the psychological well-being of older adults. Stereotype embodiment refers to a person’s internalization of age stereotypes through life-long exposure ( Levy, 2009 ). This tends to adversely affect older adults psychologically, behaviorally, and physiologically. That is, when older adults endorse negative stereotypes, they are more likely to experience a broader range of adverse health outcomes.

Through the review process, we found that the research on the relationship between ageism and the psychological well-being of older adults is at an early stage with ample room for development. The number of identified quantitative studies was small, and most studies identified were conceptual. Considering that ageism is an immediate societal issue, more quantitative studies that provide generalizable empirical evidence are needed. Additionally, very few interventions regarding mediating or moderating factors between ageism and psychological well-being have been identified. That is, no definitive answer has been given for an effective method to deal with the negative effects of ageism. The need to develop an effective intervention as a buffer against the negative effects of ageism has increased due to the pervasive ageism in current society. Finding a way to mitigate or end the negative effects of ageism, especially on the psychological well-being of older adults, would provide additional insight into successful aging.

We also found the measurement of ageism to be insufficient. Among our identified studies, Kim et al. (2015) , Lee and Kim (2016) , and Lyons et al. (2018) used Palmore (2001) ’s ageism measure, and Zhang et al. (2018) and Zhang et al. (2019) used the Levy’s et al. (2004) Image of Aging Scale. Palmore’s (2001) measure and Levy’s et al. (2004) measure assess ageism from different perspectives. While Palmer examined discrimination experienced by older adults, the Images of Aging Scale by Levy et al. (2004) could be completed by respondents of any age and asked to rate the degree to which the words or phrases are representative of older adults. That is, Zhang et al. (2018) and Zhang et al. (2019) adopted and revised ageism scales that were specifically designed to measure the attitudes of younger people toward older people. Similarly, Bai et al. (2016) employed a measure of “perceptions of aging as a burden” to examine internalized ageism of older adults. Palmore’s (2001) scale was the only one to examine how older adults felt and responded to being perceived as a stereotype. However, Palmor’s (2001) scale is inadequate since it does not account for all aspects of ageism, and because of the ambiguous terminology, it is difficult to determine how the original meaning of the items was meant to be understood ( Kang, 2020 ). Except for the five studies, other studies in this review used not established scales such as uni-dimensional or simple measures. Ageism is a subjective concept, which requires considerable effort to measure accurately. Considering that ageism can be assessed using cognitive, behavioral, and informative components, a comprehensive set of constructs is necessary, as these constructs contain reliable and valid indicators.

Several limitations were identified in this systematic review. In our search, we identified a limited number of studies; whereas a comprehensive search was conducted, we found only thirteen studies that met the criteria for inclusion. Although we aimed to include all potentially relevant studies through a comprehensive search using a wide range of search strategies, some literature could not be included. For example, we were not able to include studies in languages other than English. Further, we found several articles that discussed the ageism of older adults aged 50+ or 55+. Our review also found many qualitative studies on ageism. Therefore, we suggest that future researchers might consider setting an age cutoff of 50 for the review, which would provide a larger number of studies to consider. In addition, research will be conducted to review more diverse forms of evidence, both quantitatively and qualitatively. Using qualitative research methods can also help to deepen the understanding of ageism, which is an extremely subjective concept.

From our review, we found that ageism can be a significant threat to the well-being of older adults. Ageism is negatively associated with older adults’ psychological health, causing mental health issues such as depression and anxiety and well-being in a negative way. Considering the growing mental health needs of older adults, future research needs to focus on establishing an effective preventive intervention against ageism. The importance of reducing or preventing ageism is often noted ( Nelson, 2005 ; Raposo & Carstensen, 2015 ), but few specific methods or variables have been presented that might help to reduce ageism, especially from the perspective of older adults. The results from the systematic review contribute to building a literature base that can be used to guide future research on developing interventions for older adults.

In light of the rapid growth of aging people, research on ageism should receive greater attention. While ageism, unlike sexism or racism, is a problem that all individuals may potentially face ( Nemmers, 2005 ), its importance has been neglected, and there is much less research on ageism than on sexism and racism ( Kim, 2009 ). Significant scholarly attention should be given to ageism, considering its importance and universality, as it encompasses every generation and the growth of the population of older adults. At this important moment, this systematic review lays the foundation for future work on ageism against older adults.

Appendix B. 

PRISMA 2020 Item Checklist

Note. The PRISMA 2020 item checklist is from Page et al. (2021) .

Declaration of Conflicting Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding: The author(s) received no financial support for the research, authorship, and/or publication of this article.

Hyun Kang https://orcid.org/0000-0003-3804-7165

• Aboderin I. (2004). Modernisation and ageing theory revisited: current explanations of recent developing world and historical Western shifts in material family support for older people . Ageing & Society , 24 ( 1 ), 29–50. 10.1017/S0144686X03001521 [ CrossRef ] [ Google Scholar ]
• Avidor S., Ayalon L., Palgi Y., Bodner E. (2017). Longitudinal associations between perceived age discrimination and subjective well-being: variations by age and subjective life expectancy . Aging & Mental Health , 21 ( 7 ), 761–765. 10.1080/13607863.2016.1156050 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Ayalon L., Dolberg P., Mikulionienė S., Perek-Białas J., Rapolienė G., Stypinska J., de la Fuente-Núñez V. (2019). A systematic review of existing ageism scales . Ageing Research Reviews , 54 ( 1 ), 1–9. 10.1016/j.arr.2019.100919 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Ayalon L., Tesch-römer C. (2017). Taking a closer look at ageism: Self- and other-directed ageist attitudes and discrimination . European Journal of Ageing , 14 ( 1 ), 1–4. 10.1007/s10433-016-0409-9 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Bai X., Lai D. W. L., Guo A. (2016). Ageism and depression: perceptions of older people as a burden in China . Journal of Social Issues , 72 ( 1 ), 26–46. 10.1111/josi.12154 [ CrossRef ] [ Google Scholar ]
• Baker L. A., Cahalin L. P., Gerst K., Burr J. A. (2005). Productive activities and subjective well-being among older adults: The influence of number of activities and time commitment . Social Indicators Research , 73 ( 3 ), 431–458. 10.1007/s11205-005-0805-6 [ CrossRef ] [ Google Scholar ]
• Bryant C., Bei B., Gilson K., Komiti A., Jackson H., Judd F. (2012). The relationship between attitudes to aging and physical and mental health in older adults . Int Psychogeriatr , 24 ( 10 ), 1674–1683. 10.1017/s1041610212000774 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Bujang M. A., Sa’at N., Bakar T. M (2017). Determination of minimum sample size requirement for multiple linear regression and analysis of covariance based on experimental and non-experimental studies . Epidemiology, Biostatistics and Public Health , 14 ( 3 ) 1–9. 10.2427/12117 [ CrossRef ] [ Google Scholar ]
• Centre for Reviews and Dissemination (2009). Systematic reviews: CRD’s guidance for undertaking reviews in health care . University of York. [ Google Scholar ]
• Diener E. D., Emmons R. A., Larsen R. J., Griffin S. (1985). The satisfaction with life scale . Journal of Personality Assessment , 49 ( 1 ), 71–75. 10.1207/s15327752jpa4901_13 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Diener E., Pressman S. D., Hunter J., Delgadillo‐Chase D. (2017). If, why, and when subjective well‐being influences health, and future needed research . Applied Psychology: Health and Well‐Being , 9 ( 2 ), 133–167. 10.1111/aphw.12090 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Dovidio J. F., Pagotto L., Hebl M. R. (2011). Implicit attitudes and discrimination against people with physical disabilities . In Wiener R., Willborn S. (Eds.), Disability and Aging Discrimination . Springer. 157–183. [ Google Scholar ]
• Eibach R. P., Mock S. E., Courtney E. A. (2010). Having a “senior moment”: Induced aging phenomenology, subjective age, and susceptibility to ageist stereotypes . Journal of Experimental Social Psychology , 46 ( 4 ), 643–649. 10.1016/j.jesp.2010.03.002 [ CrossRef ] [ Google Scholar ]
• Emile M., d’Arripe-Longueville F., Cheval B., Amato M., Chalabaev A. (2014). An ego depletion account of aging stereotypes’ effects on health-related variables . The Journals of Gerontology Series B: Psychological Sciences and Social Sciences , 70 ( 6 ), 876–885. 10.1093/geronb/gbu168 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Fernandez-Ballesteros R., Olmos R., Santacreu M., Bustillos A., Molina M. A. (2017). The role of perceived discrimination on active aging . Archives of Gerontology and Geriatrics , 71 ( 1 ), 14–20. 10.1016/j.archger.2017.02.004 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Forman J. B., Chen B. Y.-P., (2008). Optimal retirement age . New York University Review of Employee Benefits and Executive Compensation. http://ssrn.com/abstract=1148271 [ Google Scholar ]
• Garstka T. A., Schmitt M. T., Branscombe N. R., Mary Lee H. (2004). How young and older adults differ in their responses to perceived age discrimination . Psychology and Aging , 19 ( 2 ), 326–335. 10.1037/0882-7974.19.2.326 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Hudson R. B. (2012). Old age in the welfare state . The Gerontologist , 52 ( 3 ), 428–433. 10.1093/geront/gns056 [ CrossRef ] [ Google Scholar ]
• Iversen T. N., Larsen L., Solem P. E. (2009). A conceptual analysis of ageism . Nordic Psychology , 61 ( 3 ), 4–22. 10.1027/1901-2276.61.3.4 [ CrossRef ] [ Google Scholar ]
• Kang H. (2020). Ageism and productive engagement: The roles of self efficacy and intergenerational contact (Publication No. 28317888) [Doctoral dissertation, University of Kansas]. ProQuest Dissertations Publishing. [ Google Scholar ]
• Kim J. H. (2009). The change in the status of older people in Korea in terms of ageism . Society and History , 82 ( 8 ), 361–391. [ Google Scholar ]
• Kim H. (2015). The mechanism of ageism: The relationship between perceived ageism and depressive symptoms in later life . (Doctoral dissertation). Retrieved from ProQuest Dissertations & Theses Global Database. (Accession No. 3724288). [ Google Scholar ]
• Kim H. J., Kang H., Johnson-Motoyama M. (2017). The psychological well-being of grandparents who provide supplementary grandchild care: A systematic review . Journal of Family Studies , 23 ( 1 ), 118–141. 10.1080/13229400.2016.1194306 [ CrossRef ] [ Google Scholar ]
• Kim I.-H., Noh S., Chun H. (2015). Mediating and moderating effects in ageism and depression among the Korean elderly: the roles of emotional reactions and coping reponses . Osong Public Health and Research Perspectives , 7 ( 1 ), 3–11. 10.1016/j.phrp.2015.11.012 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Lamont R. A., Swift H. J., Abrams D. (2015). A review and meta-analysis of age-based stereotype threat: Negative stereotypes, not facts, do the damage . Psychology and Aging , 30 ( 1 ), 180–193. 10.1037/a0038586 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Lee H. S., Kim C. (2016). Structural equation modeling to assess discrimination, stress, social support, and depression among the elderly women in South Korea . Asian Nursing Research , 10 ( 3 ), 182–188. 10.1016/j.anr.2016.06.003 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Lee S.S., Lee K.J. (2002). The stress, social support and psychological well-being of the elderly . Journal of the Korea Gerontological Society , 22 ( 1 ), 1-20. [ Google Scholar ]
• Levin J. S., Chatters L. M. (1998). Religion, health, and psychological well-being in older adults: Findings from three national surveys . Journal of Aging and Health , 10 ( 4 ), 504–531. 10.1177/089826439801000406 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Levy B. (2009). Stereotype embodiment: A psychosocial approach to aging . Current Directions in Psychological Science , 18 ( 6 ), 332–336. 10.1111/j.1467-8721.2009.01662.x [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Levy B. R., Kasl S. V., Gill T. M. (2004). Image of aging scale . Perceptual and Motor Skills , 99 ( 1 ), 208–210. 10.2466/pms.99.1 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Littell J. H., Corcoran J., Pillai V. (2008). Systematic reviews and meta analysis . : Oxford University Press. [ Google Scholar ]
• Lyons A., Alba B., Heywood W., Fileborn B., Minichiello V., Barrett C., Hinchliff S., Malta S., Dow B. (2018). Experiences of ageism and the mental health of older adults . Aging & Mental Health , 22 ( 11 ), 1456–1464. 10.1080/13607863.2017.1364347 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Moola S, Munn Z, Tufanaru C, Aromataris E, Sears K, Sfetcu R, Currie M, Qureshi R, Mattis P, Lisy K, Mu P-F. (2020). Chapter 7: Systematic reviews of etiology and risk . In: Aromataris E., Munn Z Z. (Eds.), JBI Manual for Evidence Synthesis . JBI. https://synthesismanual.jbi.global [ Google Scholar ]
• Nelson T. D. (2005). Ageism: Prejudice against our feared future self . Journal of Social Issues , 61 ( 2 ), 207–221. 10.1111/j.1540-4560.2005.00402.x [ CrossRef ] [ Google Scholar ]
• Nemmers T. M. (2005). The influence of ageism and ageist stereotypes on the elderly . Physical & Occupational Therapy In Geriatrics , 22 ( 4 ), 11–20. 10.1080/J148v22n04_02 [ CrossRef ] [ Google Scholar ]
• North M. S., Fiske S. T. (2012). An inconvenienced youth? Ageism and its potential intergenerational roots . Psychological Bulletin , 138 ( 5 ), 982–997. 10.1037/a0027843 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Organisation for Economic Co-operation and Development . (2015). Ageing and employment policies - statistics on average effective age of retirement . [Average effective age of retirement versus the normal retirement age, 2009-2014] . http://www.oecd.org/els/emp/ageingandemploymentpolicies-statisticsonaverageeffectiveageofretirement.htm [ Google Scholar ]
• Orth U., Trzesniewski K. H., Robins R. W. (2010). Self-esteem development from young adulthood to old age: A cohort-sequential longitudinal study . Journal of Personality and Social Psychology , 98 ( 4 ), 645–658. 10.1037/a0018769 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Page M. J., McKenzie J. E., Bossuyt P. M., Boutron I., Hoffmann T. C., Mulrow C. D., Moher D. (2021). The PRISMA 2020 statement: an updated guideline for reporting systematic reviews . BMJ (Clinical Research ed.) , 372 , n71. 10.1136/bmj.n71 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Palmore E. (1999). Ageism : Negative and positive . : Springer Publishing Company. [ Google Scholar ]
• Palmore E. (2001). The ageism survey: First findings . The Gerontologist , 41 ( 5 ), 572–575. 10.1093/geront/41.5.572 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Pascoe E. A., Richman L. S. (2009). Perceived discrimination and health: A meta-analytic review . Psychological Bulletin , 135 ( 4 ), 531–554. 10.1037/a0016059 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Pleasant M., Molinari V., Dobbs D., Meng H., Hyer K. (2020). Effectiveness of online dementia caregivers training programs: A systematic review . Geriatric Nursing , 41 ( 6 ), 921–935. 10.1016/j.gerinurse.2020.07.004 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Raposo S., Carstensen L. L. (2015). Developing a research agenda to combat ageism . Generations , 39 ( 3 ), 79–85. [ Google Scholar ]
• Ryff C. D. (1989). Happiness is everything, or is it? Explorations on the meaning of psychological well-being . Journal of Personality and Social Psychology , 57 ( 6 ), 1069–1081. 10.1037/0022-3514.57.6.1069 [ CrossRef ] [ Google Scholar ]
• Sabik N. J. (2015). Ageism and body esteem: associations with psychological well-being among late middle-aged African American and European American women . J Gerontol B Psychol Sci Soc Sci , 70 ( 2 ), 191–201. 10.1093/geronb/gbt080 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Schafer M. H., Shippee T. P. (2009). Age identity, gender, and perceptions of decline: does feeling older lead to pessimistic dispositions about cognitive aging? The Journals of Gerontology Series B: Psychological Sciences and Social Sciences , 65B ( 1 ), 91–96. 10.1093/geronb/gbp046 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Scharlach A., Damron-Rodriguez J., Robinson B., Feldman R. (2000). Educating social workers for an aging society . Journal of Social Work Education , 36 ( 3 ), 521–538. 10.1080/10437797.2000.10779026 [ CrossRef ] [ Google Scholar ]
• Shin D. W., Park K., Jeong A., Yang H. K., Kim S. Y., Cho M., Park J. H. 2018. Experience with age discrimination and attitudes toward ageism in older patients with cancer and their caregivers: A nationwide Korean survey . Journal of Geriatric Oncology , 10 ( 3 ), 459–464. 10.1016/j.jgo.2018.09.006 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Siguaw J. A., Sheng X. J., Simpson P. M. (2017). Biopsychosocial and retirement factors influencing satisfaction with life: New perspectives . International Journal of Aging & Human Development , 85 ( 4 ), 332–353. 10.1177/0091415016685833 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Skirbekk V. (2004). Age and individual productivity: A literature survey . Vienna Yearbook of Population Research , 2 ( 1 ), 133–153. http://www.jstor.org/stable/23025440 [ Google Scholar ]
• Snape E., Redman T. (2003). Too old or too young? The impact of perceived age discrimination . Human Resource Management Journal , 13 ( 1 ), 78–89. 10.1111/j.1748-8583.2003.tb00085.x [ CrossRef ] [ Google Scholar ]
• Solem P. E. (2005). Ageism, ageing and social participation . Nordisk Psykologi , 57 ( 1 ), 47–63. 10.1080/00291463.2005.10637360 [ CrossRef ] [ Google Scholar ]
• Streb C. K., Voelpel S. C., Leibold M. (2008). Managing the aging workforce: Status quo and implications for the advancement of theory and practice . European Management Journal , 26 ( 1 ), 1–10. 10.1016/j.emj.2007.08.004 [ CrossRef ] [ Google Scholar ]
• Tougas F., Lagacé M., Sablonnière R. D. L., Kocum L. (2004). A new approach to the link between identity and relative deprivation in the perspective of ageism and retirement . The International Journal of Aging and Human Development , 59 ( 1 ), 1–23. 10.2190/3wtn-63qq-ejmg-bgya [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Tuomi K., Ilmarinen J., Seitsamo J., Huuhtanen P., Martikainen R., Nygård C-H., Klockars M. 1997. Summary of the Finnish research project (1981-1992) to promote the health and work ability of aging workers . Scandinavian Journal of Work, Environment & Health , 23 ( 1 ), 66–71. [ PubMed ] [ Google Scholar ]
• Whitley B., Jr., Kite M. E. (2006). The psychology of prejudice and discrimination . : Thomson Wadsworth. [ Google Scholar ]
• World Health Organization . (2021). Global report on ageism . https://www.un.org/development/desa/dspd/wp-content/uploads/sites/22/2021/03/9789240016866-eng.pdf [ Google Scholar ]
• Zhang J., Nancy Xiaonan Y., Zhang J., Zhou M. (2018). Age stereotypes, flexible goal adjustment, and well-being among Chinese older adults . Psychology, Health & Medicine , 23 ( 2 ), 210–215. 10.1080/13548506.2017.1344253 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Zhang J., Zhou M., Yu N. X., Zhang J. (2019). Future time perspective and well-being in Chinese older adults: Moderating role of age stereotypes . Research on Aging , 41 ( 7 ), 631–647. 10.1177/0164027519830081 [ PubMed ] [ CrossRef ] [ Google Scholar ]