A report released Tuesday by the National Academies of Sciences, Engineering and Medicine highlighted a persistent lack of diversity among clinical trial participants, underscoring an "urgent" need to "include trials and studies that match the demographics of the disease burden under study," Usha Lee McFarling reports for STAT News.

A persistent lack of diversity in clinical trials

In the report, the authors noted that a lack of diversity among clinical trial participants has persisted despite decades of extensive reports, initiatives aimed at addressing the issue, and the creation of offices in multiple federal agencies to boost participation in clinical trials.

The authors cited several studies that demonstrate a lack of diversity in clinical trials—even for conditions that have a disproportionate impact on non-white populations.

For example, an FDA analysis of clinical trials conducted between 2015 and 2018 found that 78% of clinical trial participants were non-Hispanic white people. Notably, over 97% of participants in a Phase 2 trial of the Alzheimer's drug crenezumab were white, and only 2.8% were Hispanic, according to the report. However, Hispanic people are 1.2 times more likely to develop Alzheimer's.

In addition, a 2015 Government Accountability Office report revealed that there had been very little improvement in trial diversity since 2004. According to the new report, "research participants remain mostly white and male," in 2022.

"An equitable clinical research enterprise would include trials and studies that match the demographics of the disease burden under study," the report said. "However, we remain far from achieving this goal."

The importance of diversity in clinical trials

To illustrate why diversity in clinical trials is so important, the report's authors cited safety issues caused by a lack of diversity. In particular, the authors cited warfarin, a blood clot inhibitor that has been approved since 1951. In 2013, scientists discovered that genetic ancestry had an impact on the drug's dosing when they learned that many individuals with Asian ancestry needed lower doses and suffered excess bleeding when taking the suggested dose—a recommendation based on a trial conducted on mostly white men, the report said.

The authors cited other issues that resulted from a lack of diversity, including the inability to apply research to the entire U.S. population, difficulty recruiting an adequate number of participants, and a lack of trust in clinical research and medical establishments by members of historically excluded populations.

According to an economic analysis commissioned for the report, billions could be saved by reducing the harm of diabetes and heart disease if the U.S. experienced a 1% reduction in health disparities through more diverse clinical trials. "As the U.S. becomes more diverse every day, failing to reach these growing communities will only prove more harmful and costly over time," said report chair, Kirsten Bibbins-Domingo.

However, the cost of health disparities extends beyond dollars. "While it's easy to calculate the economic costs, it's impossible to fully calculate the emotional trauma associated with inequities in health care," said committee member Jason Resendez, who serves as president and CEO of the National Alliance for Caregiving.

How to boost diversity in clinical trials

Diversity targets for clinical trials are rarely enforced, according to the authors of the report. To address this, the authors suggested improved tracking of the diversity of trial participants, withholding funding for trials that do not meet diversity requirements, and offering financial incentives to those who increase representation.

Ultimately, the report's authors called for an "urgent" paradigm shift away from trials that focus largely on white male participants. They suggest limiting the power of the institutions that fund and conduct clinical research and increasing the power of the communities under study. The report encouraged additional funding to include and recruit more diverse clinical trial participants—an investment they said could eventually result in massive cost savings as the nation's health disparities decline.

While the committee said it found a significant amount of evidence that pointed to a lack of diversity in clinical trials, they noted that there was very little scholarly work that included recommendations to help combat the problem. The panel worked with 20 clinical trial researchers to form the following suggestions for those conducting clinical trials:

• Partner with community agencies to design studies that recruit diverse groups, while anticipating and removing barriers to participation
• Establish trust and provide them funding
• Identify stakeholders that have not historically played roles in clinical studies, including caregivers, religious leaders, or community advocates
• Prepare for the possibility that colleagues and funding agencies may not understand or appreciate the challenges associated with working to become inclusive in clinical trial research
• Recruit a diverse research team
• Grow budgets to recruit and retain diverse communities, while supporting partnerships with community organizations (McFarling, STAT News, 5/17)