Examining participant representation by sex, race, ethnicity and age in United States blood donation and blood transfusion clinical trials.

Significant inequities based on sex, race, ethnicity, and age exist among participants in clinical trials dedicated to investigating medical disease states. While general demographic data regarding blood donors and blood transfusion recipients have been studied extensively, the demographics of participants involved in blood donation and blood transfusion clinical trials are unknown. We performed a cross-sectional analysis of United States (U.S.) -based interventional blood donation and blood transfusion clinical trials registered with Clinicaltrials.gov to ascertain the composition of participants' sex, race, ethnicity, and age, as well as diagnostic conditions and geographic trial locations.Eligible trials were undertaken between July 2003 and August 2020. Thirty-eight of the one hundred and fifty-two blood donation and blood transfusion clinical trials met inclusion criteria (seven blood donation and thirty-one blood transfusion trials). While the participant dataset from trial reports were incomplete, 100 % of blood donation trials reported sex and age, 71.4 % reported race, and 42.3 % reported ethnicity. 96.8 % of blood transfusion trials reported sex, 51.6 % reported race, 38.7 % reported ethnicity, and 100 % reported age. Among 2720 participants enrolled in the seven blood donation trials, females were underrepresented (28.5 %) compared to U.S. Census data. Conversely, female (50.8 %) and male participants (49.2 %) were equally represented in blood transfusion trials (9255 participants). White participants were overrepresented in blood donation trials (73.4 %), while Hispanic or Latinos were underrepresented in both blood donation (7.7 %) and blood transfusion (8.2 %) trials compared to 2019 U.S.Census data. Only 8.3 % of blood transfusion clinical trials open to adults reported including older adults (i.e., ≥ 65yo). Despite mandatory reporting requirements and an already established framework, researchers frequently failed to report complete demographics of blood donation and blood transfusion clinical trial participants. Furthermore, various demographic groups were underrepresented in blood donation and/or blood transfusion clinical trials, including females, Hispanic or Latino individuals, and older adults. These findings demonstrate the need for implementation of strategies to ensure equitable representation of individuals in blood donation and transfusion clinical trials.