Public reporting of black participation in anti-hypertensive drug clinical trials

Background: Non-Hispanic Black people in the United States have the highest prevalence of essential hypertension. Unfortunately, clinical trials often underrepresent Black patients. We aim to understand whether trial sponsorship type is associated with representation of Black participants in anti-hypertensive drug clinical trials. Then, we contextualize our findings amongst current efforts to improve diversity in clinical research populations.

Methods: We searched ClinicalTrials.gov in May 2022 for antihypertensive drug trials. Of n = 408 trials in our initial search, n = 97 (23.77%) met inclusion criteria and were stratified by sponsorship type (industry vs non-industry). Standardized tests of difference were employed to compare characteristics of these trials, and linear regression was used to model change over time.

Results: Of 97 trials reporting results from 2010 to 2020, there were minimal differences in the percent of Black patients enrolled in anti-hypertensive clinical trials by sponsorship type. Both industry and non-industry sponsored studies had high rates of non-reporting, with slightly more non-reporting for industry (73.2%) vs non-industry (66.67%) studies. Industry funded studies reported results to ClinicalTrials.gov within 23.3 ± 15.0 months from completing studies, while non-industry funded trials reported within 18.9 ± 10.8 months.

Conclusions: Despite Black Americans carrying the highest burden of disease for essential hypertension, they are underrepresented in anti-hypertension clinical trials and their overall participation has decreased between 2010 and 2020. In addition, there is major underreporting of trial participant race. We implore researchers and funders to establish clear, meaningful targets for anti-hypertensive drug trial diversity, and improve transparency in reporting of study characteristics.