Black representation in critical care randomized controlled trials: a meta-epidemiological study

PURPOSE: The under-representation of Black people within critical care research limits the generalizability of randomized controlled trials (RCTs). This meta-epidemiologic study investigated the proportionate representation of Black people enrolled at USA and Canadian study sites from high impact critical care RCTs. SOURCE: We searched for critical care RCTs published in general medicine and intensive care unit (ICU) journals between 1 January 2016 and 31 December 2020. We included RCTs that enrolled critically ill adults at USA or Canadian sites and provided race-based demographic data by study site. We compared study-based racial demographics with site-level city-based demographics and pooled representation of Black people across studies, cities, and centres using a random effects model. We used meta-regression to explore the impact of the following variables on Black representation in critical care RCTs: country, drug intervention, consent model, number of centres, funding, study site city, and year of publication. PRINCIPAL FINDINGS: We included 21 eligible RCTs. Of these, 17 enrolled at only USA sites, two at only Canadian sites, and two at both USA and Canadian sites. Black people were under-represented in critical care RCTs by 6% compared with population-based city demographics (95% confidence interval, 1 to 11). Using meta-regression, after controlling for pertinent variables, the country of the study site was the only significant source of heterogeneity (P = 0.02). CONCLUSION: Black people are under-represented in critical care RCTs compared with site-level city-based demographics. Interventions are required to ensure adequate Black representation in critical care RCTs at both USA and Canadian study sites. Further research is needed to investigate the factors contributing to Black under-representation in critical care RCTs. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12630-023-02462-x.