Recruitment of Black Adults into Cardiovascular Disease Trials

Abstract

Background Although disproportionately affected by cardiovascular disease, Black adults remain underrepresented in clinical trials. The National Institutes of Health recommends that studies define goals for recruitment of underrepresented populations. However, the extent to which cardiovascular trials incorporate evidence-based recruitment strategies in their protocols is understudied. Methods and Results We systematically reviewed National Institutes of Health-funded cardiovascular clinical trials registered in ClinicalTrials.gov between 2000 and 2019. Based on publicly available or requested protocols, we focused on enrollment of Black adults as well as the following recruitment strategies: community-based, electronic medical record-based, and provider-based recruitment. A total of 100 clinical trials focused on cardiovascular disease were included in our analysis, of which 62% had published protocols, and 46% of trials had enrolled populations that were <25% Black. In our analysis of available trial protocols, 21% of trials defined a recruitment target for underrepresented groups; however, only one study reported achieving its enrollment goal. While 13% of trial protocols referenced community-based recruitment strategies, 5% explicitly mentioned involving community members in the trial design process. Defining recruitment targets was associated with higher enrollment of Black participants. Conclusions Black adults are underrepresented in National Institutes of Health-funded cardiovascular trials, and the majority of these trials did not specify a Black enrollment target, did not meet targets, and largely did not report specific plans to enroll Black adults in their studies. Future interventions should target trial design and planning phases before study initiation to address these enrollment disparities.

Keywords: cardiovascular disease; disparities; meta‐analysis; race and ethnicity; recruitment.

Figure 1. Preferred reporting items for systematic reviews and meta‐analyses diagram showing the flow of study selection.*

NIH indicates National Institutes of Health. *Small samples were trials enrolling <100 participants.

Figure 2. Trends in recruitment of black adults in trials from 2002 to 2017.*

A, Number of clinical trials population composed of Black participants, by timeframe. B, Number of studies that defined a recruitment target for Black participants, by timeframe. C, Number of studies that met recruitment target for Black participants, by timeframe. *“Missing” indicates not reported in available sources (eg, ClinicalTrials.gov or published results).