Blog | Promoting Diversity in Clinical Trials

Promoting Diversity in Clinical Trials

Diseases can impact different population groups unequally. The recent coronavirus proved to be no exception. In the U.S., COVID-19 had a devastating impact in particular on BIPOC (Black, Indigenous, and people of color) communities.[1]  The race to develop vaccines for COVID-19 renewed conversations about clinical research and the importance of diversity in trial participation.

Recent studies highlight the lack of diversity and inclusion in vaccine clinical trials.[2] Some populations who are excluded, due to various factors, are also the populations who will most benefit from the study drug once is it approved by the FDA for use. 

The FDA actively works to address the lack of diversity and inclusion in clinical trials. In 2020, the FDA issued guidance on increasing the participation of medically complex patients and those who need reasonable accommodations, including non-English speakers.[3] The purpose of inclusion and exclusion criteria in clinical research was examined with emphasis on revisiting the original ethical considerations that contributed to exclusion of a wider segment of the population from clinical trials. 

Groups from academia, drug research, health care, and patient advocacy also examine general diversity and inclusion issues in clinical trials.[4] 

One such group found that barriers to participation in clinical trials can include:

  • Geographical – Trial sites may be too far from participants’ homes
  • Financial Burden – Increases with lengthy travel and when frequent visits are required
  • Transportation – Significant for children, older adults, or nondrivers
  • Healthcare Fatigue – The additional burden on those already suffering from chronic illnesses
  • Historical Mistrust by Minority Populations – Past misinformation and abuse, creating a generalized mistrust of clinical research, e.g., Tuskegee Syphilis study conducted on the African American community

The findings on minority population participation are confirmed by those involved in the day-to-day conduct of clinical trials. Harish Dave, MD, Chief Medical Officer at AUM Biosciences, observes:

  • 10-15% of his company’s current U.S. study participants are from minority populations
  • Participation rates are gradually increasing, driven partly by large institution trials with a greater awareness about minority inclusion
  • A number of practices that have sizeable minority populations do not participate in research
  • The number of investigators who serve primarily minority populations is small

Idania Machado, CCRP, CCRA, Site and Resource Manager at IQVIA also shares her observations:

  • Attracting minority populations requires a knowledge of their likes and dislikes, where they work, how they commute, places of worship. Success in reaching minority populations has been achieved through targeted advertising.
  • Translation of patient-facing materials may be a challenge if site staff do not speak a particular language, despite having a large minority population in the area who do speak the language.
  • Immigrants who enroll in clinical trials may do so to get the much-needed medical care they wouldn’t otherwise be able to access due to their legal status, and other factors.

FDA guidance recommends diversifying trial populations by incorporating a number of practices into future trial design, including:

  • Broadening of eligibility criteria – As more is learned about the physiologic effects of a study drug eligibility should be expanded to include more medically complex participants
  • Inclusive trial practices – When developing protocols, ensure that the population for whom the drug has been developed are included as trial participants
  • Utilizing adaptive trial design – Allow for pre-specified trial design changes when data become available, including altering or expanding the trial population
  • Lessening travel and financial burdens for trial participants – Consider recruitment challenges that may be posed by the visit schedule, frequency of visits, visits windows. Consider use of electronic communications and remote monitoring to supplement in-person visits.
  • Adopting inclusive enrollment and retention practices – Implement strategies for public outreach and education, including patient-focused research in trial design, utilizing patient advocacy groups, and fostering community engagement to meet the needs of desired participants more effectively. Ensure trial sites in geographic locations where racial and ethnic population groups are highly represented.
  • Expanded access – Explore the potential in expanded access regulations to provide a pathway to patients with serious or life-threatening diseases or conditions for whom trial participation is not possible.

Strategies to Improve Accessibility. A 2021 workgroup of leaders in the clinical research industry explored how to improve the participation of diverse and underserved/underrepresented populations.[5] Their research revealed the following statistics related to trial demographics: 

  • African Americans
    • 4% of the overall population in America
    • 5% of the overall clinical trial population
  • Hispanics
  • 15% of the overall population in America
  • 1% of the overall clinical trial population

The work group also addressed these identified barriers to clinical trial participation with the following strategies:

Patient Centric Protocol Optimization

  • Establish goals for more diverse accrual ad outreach
  • Evaluate eligibility criteria
  • Implement participant feedback into future studies
  • Consider decentralized or hybrid trial design

Community Building

  • Invite participants through trusted local physicians
  • Leveraging community leaders
  • Meet potential participants in their own communities

Investment and Advocacy

  • Outline institutional strategies to increase trial accessibility
  • Reduce burden on participants and caregivers
  • Explore site mentorship opportunities to develop new investigators

The recommended actions set forth are still in the early stages of implementation. However, the research community is mobilizing in the direction of expanding trial design to better reflect population demographics. The actions and recommendations, when successfully incorporated into trial design and conduct, will capture data from a more diverse and inclusive patient population. In turn, this data will better reflect the needs of the population for whom the study drugs will one day become beneficial prescribed medications.



[3] The FDA Reauthorization Act of 2017; “Enhancing the Diversity of Clinical Trial Populations – Eligibility Criteria, Enrollment Practices and Trial Designs Guidance for Industry”

[4] Duke University Center for Health Policy workshop “Evaluating Inclusion and Exclusion Criteria in Clinical Trials”

[5] Advarra Research and Consulting Services