Trends in Hypertension Clinical Trials Focused on Interventions Specific for Black Adults: An Analysis of ClinicalTrials.gov

Key Words: blood pressure ■ disparities ■ race and ethnicity R epresentation of Black adults is important in the design and enrollment of hypertension trials.The SPRINT (Systolic Blood Pressure Intervention Trial), for example, enrolled 31% self-reported Black participants, which improved generalizability and race/ ethnicity treatment-effect estimation. 1 Representation alone does not replace the need for trials to be designed, and interventions tested, that consider hypertension specific to the context of the Black American experience. 2 Black adults in the United States face greater rates of cardiovascular disease, largely mediated through higher prevalence of hypertension compared with White counterparts.However, race is not a discrete biological category, but a social construct.This categorization impacts trial recruitment, retention, and environmental interactions, all of which impact clinical response to medical interventions.Interventions designed for, and tested in, Black American adults, such as BARBER-2 (Blood-Pressure Reduction in Black Barbershops) and FAITH (Faith-Based Approaches in the Treatment of Hypertension) randomized trials, are needed to address disparities in hypertension with consideration of the unique societal context of Black Americans.3,4 While there are key published trials enrolling only Black participants, the number of trials planned, running, or never published is unknown.The objective of this report was to determine the proportion of registered hypertension trials in Clini calTr ials.govdesigned for and tested in exclusively self-identified Black Americans from 2009 through 2018.All data used for this report are publicly available at Clini calTr ials.gov.Clini calTr ials.gov was queried to extract US-based interventional trials registered from January 1, 2009 to December 31, 2018. Trials were selected using the medical subject headings terms "hypertension" and "blood pressure" in the condition or disease field with characteristics abstracted by automated parsing of the Clini calTr ials.gov-generatedlist.Title, descriptive terms, and outcome measure fields were queried for "Black" and "African American" to identify candidate hypertension trials, which were then manually reviewed.Trials were deemed Black American-specific if only Black participants were enrolled or planned for enrollment based upon inclusion criteria, or explicitly noted in trial design when inclusion criterion was lacking.Trials that recruited specifically non-Black participants were excluded.Fisher exact test was used for between-group differences.This study did not require institutional review board approval because all data were acquired from the public domain.Among hypertension trials registered from 2009 to 2018 overall, 956 met inclusion criteria (Table ).The annual number of hypertension trials registered in Clini calTr ials.govincreased from 77 (2009) to 146 (2018).Fifty-two (5.4%) trials reported enrolling exclusively Black American adults.The percentage that