Imagine your doctor gives you a medicine for a serious health problem. Then you learn that very few people like you were in the studies that tested it. Would you wonder if it would work as well for you? Would you worry the side effects might be different? Would you want to know why people from your community were left out?
These are fair questions. They are at the heart of the work I have done for much of my career: diversity and representation in clinical research.
Every year, research helps create new medicines, vaccines, medical devices, and other treatments. These save and improve lives. Before a new medicine can be approved, researchers must show it is safe. They must also show it works. So we should all ask one key question: Who takes part in the studies that give us this proof?
Suppose the people in a study are not like the people who will use the medicine. Then we may miss key facts about how it works for different groups. This is not just a research problem. It is a health equity issue. And it affects all of us.
What Are Clinical Research Studies, and Why Do They Matter?
Clinical research studies use human volunteers to test medical treatments. These include medicines, vaccines, and medical devices. The studies help researchers answer big questions. Does the treatment work? What side effects might happen? How much medicine is the right amount? How does it compare to treatments we already have?
Studies happen in phases. Each phase has its own goal. Early studies often look at safety and dose. The dose is how much medicine to give. Later studies check how well the treatment works. They also watch for harm in larger groups of people. What researchers learn helps doctors, government agencies, and patients make smart choices. But how strong that proof is depends partly on who was in the study.
Think about a study of a new medicine for high blood pressure. Say most of the people in it are middle-aged men. Then researchers may know less about how the medicine works for older adults, women, or other groups. These groups may respond in different ways. This does not mean the medicine is unsafe for them. It does not mean it fails to work. It means the proof may be less sure for those groups. Representation matters because health care choices should rest on proof that reflects the people getting care.
Why People Respond Differently to Medicines?
Treatments do not work the same way for everyone. This is one of the most important facts about medicine. Many things shape how medicines affect people differently. These include age, genes, and body differences linked to sex. They also include how well your organs work, your other health conditions, and any other medicines you take. For example, the body breaks down some medicines in different ways. This can depend on small changes in genes. These changes affect enzymes, which are proteins that help the body break things down.
Some treatments need extra care for pregnant people, older adults, or people with kidney or liver conditions. Race and ethnicity can sometimes be linked to differences in health outcomes. But they are not exact stand-ins for genetic ancestry. They also do not tell us about a person’s own body or what they are exposed to in their environment. This difference is important.
I speak up for diversity in clinical research. I am not saying that everyone from the same racial or ethnic group will respond to a medicine the same way. I am asking for research that reflects the full range of human experiences, health conditions, and biology.
Social and environmental factors matter too. Think about access to health care, food, workplace exposures, and long-term stress. These can change health outcomes and how people experience treatment. They are called social determinants of health. Researchers need to think about them when they plan studies and read results.
The goal is not just to sign up people who look different. The goal is to build proof that is scientifically sound and useful in real care. It should apply to the people who need treatment.
What Happens When Underrepresented Communities Are Left Out of Clinical Research?
In the past, some groups have been underrepresented in clinical research. This means they were not included enough. These groups include some racial and ethnic minority groups. They also include older adults, people with disabilities, and people in rural or medically underserved communities.
Being left out can cause several problems:
- We know less about how treatments work for different patients.
- It is harder to spot differences in treatment response or side effects among groups that were not well studied.
- It can feed a cycle. Communities that already face health gaps get fewer chances to join the research that shapes future care.
Being left out can also make people feel that medical progress is made for other people. They may feel it is not made with them or for their community. This is a big concern when a condition hits one community harder, but that community is not well represented in studies of treatments for it.
For example, say a condition affects one community more than others. We should check whether the research behind a new treatment includes enough people from that community. The point is not to hit a number just to hit it. The point is to make sure researchers have the proof they need to understand a treatment’s benefits and risks.
A Real-World Example: Differences in Medication Response
One example is warfarin. It is a blood thinner. Warfarin helps prevent and treat harmful blood clots. But finding the right dose can be hard. Small changes in genes, such as CYP2C9 and VKORC1, can change how a person responds to it. Some of these gene changes are more common in some groups than in others. Researchers have studied how genetic information can help guide the dose.
This shows why studying only a narrow group can leave key questions unanswered. It also shows why we should not guess based only on race or ethnicity. Instead, we should look at the biology and health factors that affect how treatment works.
Another example is zolpidem. It is a medicine often used for insomnia, which is trouble sleeping. Research found that men’s and women’s bodies clear this medicine at different speeds. Because of this, the FDA recommended lower starting doses for women for some forms of the medicine.
These examples teach a bigger lesson. Researchers can look at differences across the right patient groups. When they do, they can find facts that lead to safer treatment choices that fit each person better.
Why Some Communities Are Still Underrepresented in Clinical Research
Being underrepresented does not happen on its own. There are reasons from history, from how systems are built, from institutions, and from daily life. These reasons mean some groups have had fewer chances to take part.
Past harms in medical research have led to worry about research ethics and trust in medical institutions. One example is the U.S. Public Health Service Untreated Syphilis Study at Tuskegee. We should never brush these worries aside.
It is just as important not to assume that people from these communities do not want to take part. Many are interested. But they face barriers to clinical study participation that make joining hard. Many have never been told that a study is an option as part of their care. Common barriers can include:
- Lack of transportation
- Child care duties
- Little paid time off
- Language differences
- Money concerns
- Not knowing about studies that are available
Research that looked at the views of research staff and community members found that the two groups see barriers differently. This shows why we need to listen to communities directly.
Here are some examples: A mother works full time and cares for young children. She may want to join a study but she cannot go to many appointments during work hours. A patient in a rural area may qualify for a promising study, but the nearest research center may be hours away. Another patient may never hear about a study. Their provider may not know about the research options.
These people are not necessarily saying no to research. They may just lack fair access to it. That is why improving diversity means more than adding up recruitment numbers. We also have to fix the things that affect who can take part.
What You Should Know Before Joining a Clinical Study
If you are thinking about joining a clinical research study, know that your part is valuable. Clinical research depends on volunteers. They share their time, experiences, and health information to help medical knowledge grow.
You may be asking, “Should I join a clinical study?” That choice is always yours. It should be an informed choice that you make freely. Before you sign up, you should understand:
- The purpose of the study
- The possible benefits and risks
- The steps involved
- Your rights as a participant
You should also feel free to ask questions. You can ask about the research team and what the study needs from you. You can ask about pay or reimbursement. You can ask how your personal information will be kept private.
Joining a study does not promise that you will get a health benefit. Some studies test treatments that may not work. Taking part can also have risks. You have the right to say no. You can also leave a study at any time. You will not face a penalty or lose benefits you would otherwise get.
Want to learn more? ClinicalTrials.gov lists studies in the United States and around the world. You can also ask your health care provider if there are studies that fit your health condition.
Why Clinical Research Is Personal to Me
I am a public health researcher, teacher, and clinical research professional. For years, I have studied why some groups are not well represented in clinical research. I have published research on what principal investigators think about improving diversity among participants. Principal investigators are the lead researchers of a study.
One lesson keeps shaping my work. Increasing diversity takes more than asking people to join. We must look at the systems, rules, habits, and choices that decide who gets access to research in the first place.
Who decides who can join a study? Where are studies done? Which communities hear about research chances? Who is invited to take part? And maybe most important, whose voices are included when decisions about research are made? These questions matter. Clinical research can improve health for millions of people.
That promise cannot be fully met if the benefits of research are not open to everyone. Through SpringWell360, my mission is to advance health equity and research justice. I do this by promoting education, community engagement, and more inclusive research practices.
I want people to know that clinical research does not happen only in labs or big university medical centers. It shapes the medicines your doctor prescribes. It shapes the treatments your family can get. It shapes the health care choices you make throughout your life. Everyone deserves a chance to benefit from science. And everyone deserves to know that their health and experiences matter.
Why Representation Matters in Clinical Research
When I say it matters that medicines are tested on people who look like you, I mean something much bigger than looks. I mean making sure research reflects the variety of people who will depend on its results. I mean building reliable proof that helps providers understand how treatments work across different groups. I mean removing the barriers that keep communities from research. And I mean building a health care system where new discoveries and fairness are shared goals, not competing ones.
Representation does not mean every study must include the exact same share of every group. The right mix depends on the condition being studied. It depends on the patients the treatment is meant for. It also depends on the questions researchers need to answer. But it does mean we should think about diversity on purpose, using science and ethics.
When medical research includes the people it is meant to serve, we build a stronger base. Health care can be safer, more effective, and fairer. That is why representation matters. And that is why I will keep working toward a future where everyone has a real chance to be part of clinical research.
References
- U.S. Food and Drug Administration. (2025, December 15). Enhancing Participation in Clinical Trials—Eligibility Criteria, Enrollment Practices, and Trial Designs: Guidance for Industry. Retrieved from U.S. Food and Drug Administration: https://www.fda.gov/regulatory-information/search-fda-guidance-documents/enhancing-participation-clinical-trials-eligibility-criteria-enrollment-practices-and-trial-designs
- U.S. Food and Drug Administration. (2013). Questions and Answers: Risk of Next-Morning Impairment After Use of Insomnia Drugs; FDA Requires Lower Recommended Doses for Certain Drugs Containing Zolpidem (Ambien, Ambien CR, Edluar, and Zolpimist). Retrieved from U.S. Food and Drug Administration: https://www.fda.gov/drugs/drug-safety-and-availability/questions-and-answers-risk-next-morning-impairment-after-use-insomnia-drugs-fda-requires-lower
- National Institute of Mental Health. (2005). Points to Consider About Recruitment and Retention While Preparing a Clinical Research Study. Retrieved from National Institute of Mental Health, Clinical Research Toolbox: https://www.nimh.nih.gov/funding/clinical-research/clinical-research-toolbox/nimh-clinical-research-toolbox
- National Academies of Sciences, Engineering, and Medicine. (2025). Toward a Framework to Improve Diversity and Inclusion in Clinical Trials: Proceedings of a Workshop. Washington, DC: The National Academies Press. Retrieved from National Academies Press: https://nap.nationalacademies.org/catalog/28587/toward-a-framework-to-improve-diversity-and-inclusion-in-clinical-trials (DOI: https://doi.org/10.17226/28587)
