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
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
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
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
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:
Interpersonal and logistical barriers:
- Lack of trust in researchers or research institutions
- Ineffective communication stemming from differences in
language, culture, or
- 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
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
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
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
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."
Addressing the Underrepresentation of African Americans in Clinical
Trials. Future posts will discuss underrepresentation of
various minority populations.