Importance of Diversity in Clinical Trials

Expanding participation of racial and ethnic minorities in clinical trials is vital to ensure representation, achieve compliance, and accelerate drug development.
Importance of Diversity in Clinical Trials Blog Post Image

FDA Guidance to Improve Diversity in Clinical Trials

Ensuring meaningful representation of racial and ethnic minorities in clinical trials for regulated medical products is fundamental to public health.

Recently, the FDA has been paying more attention to the importance of clinical trial diversity in creating drugs and medical devices. Over the next decade, the FDA’s big-picture objectives include:

  • Delivering participation parity for racial and ethnic populations who are currently underrepresented.
  • Improving the generalizability of research conclusions to the population at large.

The 2022 draft industry guidance provided non-binding recommendations to create a race and ethnicity diversity plan. These included the types of participant data to share with the FDA and which research milestone(s) to submit.

Importance of Diversity and Inclusion in Clinical Trials

Patients and the FDA are paying increasing attention to equity and inclusion in medicine. Clinical trials operating without a robust diversity plan compromise the credibility of their results. It can also lead to negative patient outcomes that could have been discovered and addressed.

Changes in clinical trial design may soon become necessary if not a legal requirement. If you choose to wait, it could lead to bottlenecks down the road, ultimately impacting operational effectiveness and slowing the progress of your research.

Expressing a good-faith desire to conduct more broadly representative research will not be enough. To meaningfully address racial and ethnic diversity in clinical trials, consideration must be given to every stage, from trial design and exclusion criteria to patient recruitment and reporting results to the FDA.

Prioritizing inclusion in clinical trials can help build patient trust, leading to better insights and valuable trial data. It also positions you advantageously to secure clinical trial funding and result in more approvals.

Patients with Limited English Proficiency (LEP)

According to the FDA, clinical trials must expand participation for all racial and ethnic minorities, sex, gender, identity, age, socioeconomic status, disability, pregnancy and lactation status, and comorbidities.

Patients with limited English proficiency (LEP patients) account for many of the FDA’s expectations for clinical trial diversity, such as racial and ethnic minorities. Despite rights and protections, LEP patients are some of the least-served patients in the U.S. Delivering an equivalent standard of care necessitates careful foresight and planning.

This involves implementing effective communication strategies, ensuring accessibility to information, and addressing potential language barriers throughout the clinical trial process. By proactively anticipating and accommodating the linguistic challenges faced by LEP patients, researchers can enhance the inclusivity and overall effectiveness of clinical trials, ultimately contributing to more robust and meaningful results.

Representation Matters: Clinical Trial Participation Rates, Disease Rates, and Demographics

There is plenty of data that confirms the underrepresentation of LEP patients in clinical trials—so much so that the FDA has a division dedicated to Minority Health and Health Equity. Its Clinical Trial Diversity Fact Sheet acknowledges that research participation among racial and ethnic minorities lags behind the U.S. population.

Consider that the FDA’s Center for Drug Evaluation and Research (CDER) approved 53 novel drugs in 2020. According to the 2020 Drug Trials Snapshots Report, of these associated trials, 75% of participants self-reported their race as white.

FDA CDER 2020 Drug Trials Snapshots vs U.S. Population 2022, Race and Hispanic Origin

White White, not Hispanic or Latino Black or African-American Asian Hispanic
U.S. Population %
Clinical Trial Participation %

Sources: FDA CDER, 2020 Drug Trials Snapshots Report and United States Census Bureau Population Estimates, July 2022.
*NR: Not reported.
** This data does not distinguish Hispanic/Latino individuals who identify as white, which accounts for a significant proportion of LEP patients. And, while an indicator of racial and ethnic diversity, ‘language spoken at home’ is not a demographic data point collected at this time, making it difficult to benchmark your firm’s engagement with LEP patients to industry peers.

Individual and structural social determinants of health can play a significant role in drug efficacy, side effects, and outcomes. Clinical trials that better represent the population at large and/or the populations most likely to use this drug yield more accurate data. Diversity and inclusion in clinical trials could help reduce disparities in health outcomes experienced by racial and ethnic minorities.

Without improving representation in research, we can continue to expect:

  • Compromised generalizability of research findings to the broader population.
  • Lack of faith and trust in treatment options among vulnerable populations.
  • Hindered innovation.
  • Obscured safety or efficacy outcomes.
  • Uneven disease burdens.


Disease Burdens in Underrepresented Populations

Scholars of clinical trial diversity have estimated that eliminating life expectancy disparities for the three most common conditions has a total value to society of approximately $11 trillion. The diseases in question are diabetes, hypertension, and heart disease. In some instances, LEP populations experience these conditions at higher rates.

This is observed not only with common diseases but also rare autoimmune conditions, COVID-19, asthma, HIV, and tuberculosis. Racial and ethnic minorities receive life-altering diagnoses more frequently than white Americans for these diseases. Excluding these communities from research can greatly impact mortality rates.

For example, the prophylactic HIV medicine Descovy® (PrEP) Phase III study focused on the gay and bisexual male community. As a result, the on-label use for Descovy® includes cisgender men and transgender women considered at risk of contracting HIV by the CDC. Those assigned female at birth—even if they are also at risk of contracting HIV—must use Descovy® off-label.

While using Descovy® in this context is legal and allowed, these patients face additional barriers to obtaining HIV prevention medication. Plus, direct-to-consumer advertising cannot speak to off-label uses, further contributing to misinformation about who is eligible for this prophylactic medication.

The fact that Hispanic Americans made up nearly 30% of all HIV infection cases in 2019 underscores the life-or-death significance of health equity—determining who thrives and who faces a lifelong health battle. As more HIV drugs are being developed and a wider range of biological applications are being explored, embracing broader inclusion is translating hope into action.

By The Numbers: Disease Burdens Among LEP Patients

Uneven disease burdens in diverse populations stand as reason alone to advocate for more inclusive clinical trials. While not exhaustive, it emphasizes the diverse health risks by racial and ethnic populations, underscoring the importance of their participation in research for biomedical firms.

12% 7%
Percent of Latinos with Type 2 Diabetes
Percent of non-Hispanic white people with Type 2 Diabetes

Source CDC

Infant mortality rate per 1,000 live births, 2018

4.9% 4.6%
Non-Hispanic White

Source CDC

Puerto Rican Community: 20% Higher Infant Mortality Rate
Compared to non-Hispanic Whites in 2018

Source CDC

Men Liver and IBD Cancer Incidence Rates per 100,000 Stomach Cancer Rates per 100,000
Non-Hispanic White

Source: NCI 2021. Seer Cancer Statistics Review, 1975-2018

Women Liver and IBD Cancer Incidence Rates per 100,000 Stomach Cancer Rates per 100,000
Non-Hispanic White

Source: NCI 2021. Seer Cancer Statistics Review, 1975-2018.

Percentage of Reported Cases of Chronic Hepatitis B Virus (HBV) Infection, 2013-2016

30.1 13.5
Asian/Pacific Islander
Non-Hispanic White


More Common Among Asian-Americans

Source: CDC.


Health Insurance Coverage by Community

When seeking more diverse clinical trial candidates, health insurance coverage is a factor that must be considered. Those less likely to seek a doctor’s care may also be less likely to hear about a research trial that could help their condition or further their search for cures and treatments.

Hispanic Americans have the highest uninsured rates of any racial or ethnic group within the United States. In 2020, the Census Bureau reported that just 49.9% of Hispanics had private insurance coverage, compared to 73.9% for non-Hispanic whites. 

The uninsured rate of Asian Americans (6.6%) is nearly on par with non-Hispanic white Americans (6.3%), but rates vary among subgroups. 9.6% of Thai Americans, 8.3% of Vietnamese Americans, and 7.3% of Hmong Americans are uninsured. Despite higher rates of health plan coverage overall, Asian Americans are less likely to seek a doctor’s care than non-Hispanic whites.


PGLS’s Role in Advancing Language Access in Clinical Trials

The imperative for meaningful representation of racial and ethnic minorities in clinical trials is evident in the FDA’s commitment to health equity. It is further underscored by the negative impact on patient outcomes and the generalizability of trial results when diverse populations are excluded.

Addressing these issues is not just a matter of ethical and equitable practice; it has real-world implications. Improving diversity and inclusion in clinical trials can lead to more accurate data and reduce disparities in health outcomes, ultimately benefiting society as a whole.

PGLS offers high-quality translation services in over 200 languages, ensuring excellent experiences for Limited English Proficient (LEP) patients in clinical trials. Our highly qualified pool of linguists can facilitate sensitive patient interactions with both empathy and accuracy. We are dedicated to assisting you in navigating the intricacies of FDA and HIPAA requirements, utilizing our trusted in-country linguists, subject-matter experts, board-certified medical doctors, and sophisticated translation software to bridge language and culture for compassionate and effective communication.