Healthcare Commentary

Left Out of the Data: The Diversity Gap in Clinical Trials

By Lesandu Wickramasinghe, YouthCare Connect 7/27/2026

The use of a medication is usually based on the assumption that it has been tested on people similar to you, with the same biology, background risks, etc. Yet, for many Americans, this assumption is not valid, as the drugs available in pharmacies and the clinical treatments endorsed by guidelines have mostly been tested on white patients. This leaves others asking, “Does this work for me?” The lack of diversity in clinical trials is not just an insignificant mistake in administration. It is a deep-rooted failure of the medical system that exposes minority patients to health risks every time they take a prescription drug.

A Gap That Has Persisted for Decades

For a very long time, minority involvement in clinical trials has been absent. To correct this situation, Congress passed the NIH Revitalization Act in 1993. Yet, even after more than three decades, the statistics are very depressing. The FDA reported that in 2020, white individuals made up 75% of clinical trial participants. At the same time, Black, Hispanic, and Asian individuals taken together constituted very small percentages, even though almost 40% of the U.S. population is made up of different racial and ethnic minority groups (FDA, as cited in University of Minnesota Masonic Cancer Center, 2023). In an analysis by Lancet Regional Health, it was shown that while Black individuals faced 21% of the COVID-19 deaths during the pandemic, they only made up 3% of the major vaccine trial participants (Al-Khalil et al. 2022).

What Is Lost When Data Is Incomplete

This goes well beyond a matter of justice. It is also a matter of science. If a medicine is mainly tested on white patients, and then it is given to everyone, the scientists simply do not know if the medicine will work in the same way in different populations. Genetic differences, variations in metabolism, and even the symptoms of the disease can all differ per ancestry. One research focusing on neuroscience clinical trials found that apart from one trial, Black participants were absent in all other trials. Meanwhile, the authors stated that differences in enrollment might cause overlooked variations in how different treatments work (Acuña et al. 2024). If you are left out of the data, then the medicine has not really been developed for you.

The Human Cost

There is a truth behind this data that needs to be spoken. When a Black woman has breast cancer and receives a treatment protocol based almost entirely upon data from white patients, it is no longer evidence-based medicine. It is an educated guess. When a Hispanic man is told a new therapy has a strong success rate, that rate is based on data from a study that may have included populations that don’t even remotely look like him. The gap in diversity in research has a ripple effect that is not limited to academic papers but spans all clinical interactions. It is present in treatment choices, in dosages, in side-effect profiles. The difference in who gets studied and treated isn’t academic, it is as real as men and women, and it results in different outcomes, disparities, and ultimately lives.

Moving Toward Inclusion

The fixes are obvious. Scientists and public health campaigners have argued for loosening eligibility rules so that people with controllable comorbidities would not be automatically disqualified, increasing the number of trial locations to community health centers and federally qualified health centers where the most ethnic minority populations are treated, offering monetary help and navigation services to the patients, and making it mandatory that race and ethnicity data are collected and used in decision making of whether to approve a trial (ASCO, 2022; HHS OIG, 2024). The FDA is already taking steps in this direction by updating its diversity action plan requirements for drug manufacturers, but implementation and accountability are still being developed.

Medicine cannot call itself universal while it continues to test itself on only a fraction of humanity.