Black adults are disproportionately affected by cardiovascular disease but underrepresented in relevant clinical research trials in the United States. In a new paper published in the Journal of the American Heart Association, researchers from Beth Israel Deaconess Medical Center (BIDMC) systematically reviewed federally funded cardiovascular disease trials run between 2000 and 2019 to determine whether various recruitment strategies impacted the number of Black participants enrolled. Their research is the first such analysis of clinical trials to examine investigators’ planning documents with respect to accruing diverse research participant populations.
While the team found a link between defining recruitment targets for underrepresented populations and higher enrollment of Black participants, the majority of trials either did not specify a Black enrollment target or, if they did, they did not meet such targets. Ultimately, the researchers found that Black participants are still significantly underrepresented in cardiovascular disease trials, and enrollment rates have not improved over time.
“There’s a critical need to increase the enrollment of Black participants in clinical trials to ensure that the scientific literature guiding clinical practice better reflects the diversity of individuals in the United States—otherwise the care of Black Americans is informed by data predominantly from non-Black participants,” said corresponding author Stephen Juraschek, MD, PhD, a clinician researcher in the Division of General Medicine and Primary Care, Section for Research, at BIDMC and assistant professor of medicine at Harvard Medical School. “Previous efforts to address lower participation by Black adults have focused on individual or community characteristics, such as mistrust, transportation, and socioeconomic factors. However, investigators also play a critical role during the study design phase by defining recruitment goals and formulating recruitment strategy to meet those goals.”
The team looked at recruitment strategies, including active and passive recruitment, community-based recruitment, electronic medical record-based recruitment, and healthcare provider referrals, in 100 studies. Active recruitment included direct outreach to potential participants initiated by the research team as opposed to passive recruitment, in which participants had to initially express interest based on informational ads. Sixty-two of the studies had protocols outlining recruitment efforts available. Among the 90% of trials that reported active recruitment strategies, just 5% of trial protocols explicitly mentioned community members as being part of the trial design process, and 3% of trials had community members outside academic medical institutions as coauthors.
Nearly a quarter of the trials did not specify what percentage of enrollees identified as Black. Trials that did not define recruitment targets often had an inadequate representation of Black participants. While 21% of studies explicitly mentioned target goals for recruitment of historically underrepresented populations, just one trial met its goal for enrolling Black participants.
Perhaps most alarmingly, Juraschek and colleagues observed no significant changes in the recruitment of Black adults between 2002 and 2017, nor was there a significant change in the number of trials defining enrollment targets.
This work was supported by the National Heart, Lung, and Blood Institute.
Edited by Gary Cramer