Aligning Demographic Recruitment Data and the Goals of Diversity in Clinical Research in the U.S.

Clinical Researcher—February 2023 (Volume 37, Issue 1)


David J. Morin, MD, FACP, CPI, FACRP


Central to the discussion of assuring access to safe and effective therapeutics and devices is the recruitment of study participants who represent those destined to use these products. Historical gaps in the inclusion of women and racial minorities in clinical trials prompted policy as early as 1993, with the National Institutes of Health (NIH) Revitalization Act mandating the inclusion of these groups in trials conducted by those receiving NIH funding. However, requirements for reporting on racial and gender demographics in these trials are all too often still met with missing or incomplete data.

A study published last month (January 2023) in the open access journal Scientific Reports offers a detailed review and meta-analysis of gender, racial, and ethnic demographics in nearly 3,000 studies conducted in the U.S. between 2008 and 2019. The authors compared study demographics with U.S. Census data, and while there were some differences in the demographic percentages from year to year and for various subcategories, the results show that women remain slightly underrepresented in Phase II but accurately represented in Phase III trials.

Demographic representation according to race showed “underrepresentation” compared to their population percentage estimates for Hispanics, American Indians and Alaskan Natives, Asians, Whites, and multiracial study participants. At the same time, Native Hawaiians, Pacific Islanders, and Blacks were “overrepresented.” Black or African Americans represented 17% overall for all trials reviewed but 12.3% of the U.S. population based on the 2010 U.S. Census data.

The authors report that their findings “should be considered in the context of several limitations,” given the challenges with reporting race/ethnicity in trial databases. Nevertheless, the results show a mixed picture of successes and the need for continued efforts. This retrospective review comparing U.S. demographic data on race and gender to actual enrollment is helpful; still, the purpose of including a diverse study population is to ensure the results regarding safety and efficacy apply to all user groups.

U.S. Food and Drug Administration draft guidance on diversity plans issued in April 2022 encourages sponsors to submit a plan “as soon as is practicable during medical product development.” Sponsors should identify the influence of gender, race, and ethnicity on the safety and effectiveness of those most likely to be affected by the disease under study. As noted in the draft guidance, diversity in study enrollment goes beyond race and ethnicity since other demographic populations are underrepresented in trials. These include “gender identity, age, socioeconomic status, disability, pregnancy status, lactation status, and co-morbidity.”

Sponsor challenges to creating a plan to identify groups may include the rapidly changing demographics of race in the U.S. Compared to 2010, the 2020 U.S. Census revealed that the population is much more diverse, with a decline in the white population by 8.6% and a 276% increase in those who identify as multiracial (two or more races) from 9 million to 33.8 million. During the lifecycle of a drug, significant demographic changes will reinforce the need for continued safety monitoring but may require additional information on therapeutic benefits.

There are many scholarly articles on how to increase diversity in clinical trials. Approaches to increasing participation will likely be as diverse as the groups identified. Efforts to understand and define the most effective methods should begin with accurate and complete reporting of our study population group and sub-group characteristics. Lastly, central to any diversity initiative’s success is the public’s trust in the research process itself.

David Morin
David J. Morin, MD, FACP, CPI, FACRP,
is Immediate-Past Chair of the Association Board of Trustees for ACRP. In addition to his volunteer duties with ACRP, he provides patient care and serves as the Director of Research at Holston Medical Group, a multispecialty practice in Tennessee and Virginia, and is Director of the High-Risk Disease Prevention program for a Fortune 100 company.