Study Reveals Racial and Demographic Disparities in Clinical Trials

Gloved hand of masked person using eye dropper under microscope

Key Takeaways

  • Studies suggest that there is an underrepresentation of marginalized communities within clinical trials, especially individuals from Black and Latinx communities.
  • Adults over the age of 65 are also underrepresented.
  • Contrary to the researchers' hypothesis, adult ciswomen are overrepresented in trials.
  • Equity within trials will lead to better outcomes for the general population.

The COVID-19 pandemic sparked a massive undertaking to develop a vaccine, which inevitably required massive amounts of data acquired from clinical trials.

While the presumed goal of the clinical trial criteria is accuracy, efficacy, and objectivity, there is a recurrent issue of marginalized populations making up low percentages of participants within clinical trials across the board.

A recent study published in JAMA Network Open reviewed 230 trials based in the United States, including over 219,000 participants, to answer the question: "Do vaccine clinical trials equitably represent individuals who identify as members of underrepresented racial/ethnic groups, are women, and are people aged 65 years or older?"

Their hypotheses surrounding the lackluster representation of communities of color—particularly the Latinx and Black communities—were spot on. Based on this research, experts conclude that “...diversity enrollment targets should be included for all vaccine trials targeting epidemiologically important infections.”

Health Equity and Clinical Trials

The numbers and percentages of racial/ethnic minority, female, and older individuals in the research studies were compared with US census data from 2011 and 2018. Racial groups included Black or African-American, Latinx, Asian, and Alaska Native or Native American. The older adult category included individuals over the age of 65.

White participants were overrepresented, accounting for almost 78% of the trial population. Black and Latinx participants made up less than 12%, Asian participants were less than 6% of the group, and Native participants made up less than 0.5%.

The results of the study showed that racial and ethnic groups, as well as adults over the age of 65, are underrepresented in clinical trials. The longstanding history of medical mistreatment and malpractice alongside gender parity in varying situations led the researchers to assume both women and marginalized ethnic groups would be underrepresented within the trials.

However, ciswomen ultimately accounted for a majority of trial participants, resulting in an overrepresentation.

Recent Examples

Consider this disparity with the fact that the Black American community accounts for 30% of the COVID-19 cases despite making up less than 14% of the total US population, and the dangers of underrepresentation within the testing become even more apparent. Again, the result is the marginalized communities receiving the short end of the stick.

There are many diseases and conditions that affect varied demographic groups differently or more frequently than others. Marginalized communities are often left out of the conversation around testing and research, sometimes leading to misdiagnosis when an illness arises.

Because individuals with varied ethnic and racial backgrounds can present conditions differently, sometimes symptoms are dismissed or overlooked because they look different than what a doctor may have studied or experienced.

Krystal Jagoo, MSW

Medical racism in the US has contributed to vaccine hesitation from racialized folx, and these study results are particularly discouraging as they only serve to confirm the fears of BIPOC folx that there may be adverse outcomes.

— Krystal Jagoo, MSW

This is common with skin conditions, as textbooks, studies, and trial photos often present lighter-skinned individuals' symptoms, which are bound to vary from someone of color. For example, if a doctor was looking for the documented symptoms of eczema as "small, red bumps, which can be very itchy" accompanied by a photo of a white person, they could easily miss the appearance of the same condition on a person of color.

This too has shown up during the COVID-19 pandemic. University of California dermatologist Jenna Lester was shocked by the significant absence of examples of the dermatological effects that the virus can have on dark skin, saying, “I was frustrated because we know COVID-19 is disproportionately impacting communities of color...I felt like I was seeing a disparity being built right before my eyes.”

A Historical Issue

Unfortunately, skin conditions are just one example, and the disparity is not new. Medical malpractice is a likely contributor to the low numbers of Black and Brown participants in clinical trials.

Communities of color have had a sordid history with being able to trust medical advice, especially if it comes from someone who is not familiar. There are horror stories like that of Henrietta Lacks, The Tuskegee Experiment, and the horrific legacy of J. Marion Sims, known as the "Father of Gynecology."

The problem of varied racial groups being left out of these trials and subsequent treatment extends beyond inconvenience. Without the proper inclusion of varied backgrounds, medications and treatment cannot be accurately generalized for the public.

Jenna Lester, MD

I was frustrated because we know COVID-19 is disproportionately impacting communities of color...I felt like I was seeing a disparity being built right before my eyes.

— Jenna Lester, MD

The issue itself is not new, and neither is the acknowledgment that this problem exists. In 2000, the National Institutes for Health put forth a Revitalization Act to enforce race and gender diversity among clinical trials. Despite this, a study done in 2017 showed that less than 2% of participants were from marginalized communities.

Centuries of medical malpractice and dismissal of Black and Brown people contributes to the systemic racism within the U.S. Krystal Jagoo, MSW, RSW, says, “Unfortunately, it is difficult to imagine how progress can even be made regarding this health equity injustice as the very reality of the need for such inclusion of marginalized groups in research may contribute to their apprehension to participate in such trials.

Jagoo says, "With research like this, it is easy to understand why oppressed folx in the U.S. can often feel hopeless about their outcomes in this country. Especially given how medical racism in the U.S. has contributed to vaccine hesitation from racialized folx, and these study results are particularly discouraging as they only serve to confirm the fears of BIPOC folx that there may be adverse outcomes..”

What This Means For You

This study underscores the disparities within our medical and scientific community, ultimately serving as yet another reminder of the need for cultural awareness initiatives as well as diversity of age, race/ethnicity, gender expression/identity, ability, sexuality, and native language within the medical field in an effort to assess conditions as fully and equitably as possible.

This data supports the necessity of analyzing the effects of a White-dominant and elder-exclusive culture and the ways in which it affects our collective health. Clinical and vaccine trials are vital to medical innovation, and without addressing the gaps that they so often have, marginalized communities will continue to get left behind and misdiagnosed.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

5 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Lester JC, Jia JL, Zhang L, Okoye GA, Linos E. Absence of images of skin of colour in publications of COVID-19 skin manifestations. Br J Dermatol. 2020;183(3):593-595. doi:10.1111/bjd.19258

  3. Encyclopedia Britannica. Henrietta Lacks.

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