Black Americans are more willing to participate in medical studies led by Black doctors and researchers, perceiving them as more trustworthy, finds a new study co-authored by a Cornell economist.
The findings suggest diversifying the leadership of clinical trials could improve enrollment by underrepresented groups including Black Americans, who comprise 13% of the U.S. population but just 5% of clinical trial participants, while suffering disproportionately from disease and premature death.
More proportional racial representation in clinical trials would help ensure that the benefits and risks of new treatments are understood across populations, and encourage broader adoption of preventive or potentially life-saving treatments, the researchers said.
"If clinical trials don't adequately represent all the populations that are going to use a drug, this may threaten the generalizability you would hope to have," said Romaine Campbell, a postdoctoral researcher and incoming faculty member in the Cornell Jeb E. Brooks School of Public Policy and in the Department of Economics. "You don't fully understand whether sub-populations will benefit in the same way as those involved in the trials do."
Campbell is an author of "Investigator Racial Diversity and Clinical Trial Participation," published in the March issue of the Journal of Health Economics. Co-authors are Dr. Marcella Alsan, a physician and professor of public policy at Harvard University's Kennedy School of Government; Lukas Leister, a doctoral student in economics at the Universitat Pompeu Fabra in Barcelona, Spain; and Dr. Ayotomiwa Ojo, a resident at Northwestern Memorial Hospital in Chicago.
Black Americans' underrepresentation in clinical trials has been well documented. A recent review of cancer trials found Black patients accounted for 5% of the samples in trials for novel checkpoint inhibitors. Relatively high-profile COVID vaccine trials were more representative, at nearly 9%. But in a recent trial for a drug to treat Alzheimer's disease - for which Black Americans are at higher risk - only 19 of more than 1,700 participants were Black.
A 2022 report by the National Academies of Sciences, Engineering and Medicine, whose authors included Alsan, offered more than a dozen recommendations for improving representation in clinical trials and research. Along with issues such as compensation and schedule flexibility, the recommendations included diversifying the principal investigators who run clinical trials, recognizing that less than 4% of investigators funded by the National Institutes of Health (NIH) are Black, according to the researchers.
To test that idea's potential effectiveness, the research team ran an online survey with a nationally representative sample of more than 320 Black Americans. Study participants viewed a randomly selected head shot of a principal investigator - white or Black, male or female - sourced from the website of the NIH's Intramural Research Program, the world's largest biomedical research institution. Machine learning tools rated the photos to ensure consistency in quality, investigator age and emotions conveyed.
Informed that the person in the photograph led NIH research studies, study participants were asked how interested they would be in participating if that person were leading a medical study to prevent a disease relevant to their community.
The results showed a significant increase - 12.6% - in study participants' willingness to participate in clinical trials run by people of the same race. The medical researcher's gender, however, was not a factor.
Further analysis revealed that trust was the most important factor influencing the increased willingness to participate. Impressions of investigators' attractiveness and education also mattered, but to a lesser extent.
Distrust of medical professionals and institutions is a known contributor to underrepresentation in clinical trials by Black Americans, who historically were excluded or in some cases unknowingly subjected to medical experimentation, as in the U.S. Public Health Service's infamous Tuskegee syphilis study, conducted from 1932 to 1972. Strategies to build trust therefore are critical, the researchers said.
While increasing the numbers of Black clinical trial leaders may be a longer-term goal, Campbell said the survey findings suggest diversity could be leveraged more broadly to improve patient representation in trials. One recent example, he said, is outreach that sought to build trust in COVID vaccines by highlighting Black scientists' involvement in their development.
"We should be more deliberate about diversifying the pool of medical professionals, and in the interim, there are benefits to being strategic about diversity within the existing pool of principal investigators," Campbell said. "Particularly for clinical trials, we want to make sure we have representative samples so we can best extract the benefits of medical innovation."
The research was supported by the National Science Foundation.
