Breakthrough Patient Recruitment

: Redefining Barriers to Minority Participation in Clinical Trials

Redefining Barriers to Minority Participation in Clinical Trials

Content Specialist

April is Minority Health Month, a month-long effort to raise awareness about health disparities that continue to affect racial and ethnic minorities. In this series, titled "Recognizing Unseen Opportunities: Increasing Recruitment and Retention of Ethnic and Racial Minority Populations in U.S. Clinical Trials," the Healthyist explores barriers to minority participation in clinical trials and discusses the importance of addressing the issue.

As the ethnic and racial diversity of the United States continues to grow, increasing the representation of minority groups in clinical trials is vital. Currently, the proportion of racial and ethnic minorities enrolled in and reported on in clinical trials falls short of the amount needed to represent the actual proportion of minorities living in the United States.

Although the research community has long acknowledged the need to increase enrollment of minorities in clinical trials, the NIH Revitalization Act of 1993 and the Department of Health and Human Services' Healthcare Research and Quality Act of 1999 reinforced this goal. 

Why is increasing representation of minorities in clinical trials important?

The underrepresentation of ethnic and racial minorities compromises scientists' ability to apply study results and raises ethical questions about the standard of care for minority populations. Certain medications have a different effect among some racial and ethnic minority groups. Thus, without a proportional presence of minorities in clinical trials, it may not be possible to accurately predict how a medication will affect certain minority groups until it has been marketed.

Meanwhile, although there is a higher prevalence of some diseases among minorities, there is not increased enrollment of those groups in clinical trials for those diseases. Understanding any diverging effects of treatment in minority groups is imperative for diseases that disproportionately affect minorities.  

Why are minorities underrepresented in clinical trials?

More research is needed to accurately assess minorities' underrepresentation in clinical trials. Data on minorities who do participate in clinical trials is typically underreported. As a result, it has not been possible to evaluate the effectiveness of different recruitment and retention strategies on various minority groups. Thus, the answer to this question is not an easy one, and there is a lot we have yet to learn. But we do know that barriers to minority enrollment in clinical trials can be grouped into two categories:

Institutional barriers:

Interpersonal and logistical barriers:

  • Lack of trust in researchers or research institutions
  • Ineffective communication stemming from differences in language, culture, or health literacy  
  • Length of study visits, lack of child care, or lack of transportation support

It may be possible to address interpersonal or logistical barriers within a clinical trial. But long-term solutions to address underrepresentation of minorities in clinical trials will require large-scale, institutional reforms.

Addressing barriers effectively

Many studies identify lack of trust and cultural differences as primary barriers to enrollment in clinical trials. However, other studies have shown that once given the opportunity, racial and ethnic minorities are not less likely to enroll in a clinical trial than Caucasians, suggesting that recruitment efforts should focus more on access to clinical trials and less on minorities' pre-conceived notions about research.

Factors to consider in recruitment and retention

Challenges to recruitment and retention are unique to each racial and ethnic minority group. Additionally, factors such as education, socioeconomic status, acculturation, age, gender, and geography may affect how receptive individuals are to a study's messaging and media choices.

It is also noteworthy that these same factors overlap with general participation in clinical trials. Being male, well educated, middle class, and living in an area of higher population density are often characteristics of those most likely to participate in clinical trials. These characteristics cut across racial and ethnic lines, suggesting that enrolling members of minority groups who fit these characteristics may represent an underutilized opportunity.

Finally, large-scale strategies such as social marketing and health care provider referrals remain among the most effective recruitment tools across the board. Yet, nuanced differences in how different minority groups most effectively receive information about clinical trials suggest that selectively tailored approaches would also be effective.

This is part 1 of the Healthyist's series "Recognizing Unseen Opportunities: Increasing Recruitment and Retention of Ethnic and Racial Minority Populations in U.S. Clinical Trials." Part 2: Addressing the Underrepresentation of African Americans in Clinical Trials. Future posts will discuss underrepresentation of various minority populations.

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