Race/ethnicity reporting and representation in US clinical trials: A cohort study

Background Systemic progress in improving trial representation is uncertain, and previous analyses of minority trial participation have been limited to small cohorts with limited exploration of driving factors. Methods We analyzed detailed trial records from all US clinical trials registered in ClinicalTrials.gov from March 2000 to March 2020. Minority enrollment was compared to 2010 US Census demographic estimates using Wilcoxon test. We utilized logistic regression and generalized linear regression with a logit link to assess the association of possible drivers (including trials' funding source, size, phase, and design) with trials' disclosure of and amount of minority enrollment, respectively. Findings Among 20,692 US-based trials with reported results (representing similar to 4 center dot 76 million enrollees), only 43% (8,871/ 20,692) reported any race/ethnicity data. The majority of enrollees were White (median 79 center dot 7%; interquartile range [IQR] 61 center dot 9-90 center dot 0%), followed by Black (10 center dot 0%; IQR 2 center dot 5-23 center dot 5%), Hispanic/Latino (6 center dot 0%; IQR 0 center dot 43-15 center dot 4%), Asian (1 center dot 0%; IQR 0 center dot 0-4 center dot 1%), and American Indian ( 0 center dot 0%; IQR 0 center dot 0-0 center dot 2%). Median combined enrollment of minority race/ethnicity groups (Black, Hispanic/Latino, Asian, American Indian, Other/Multi) was below census estimates (27 center dot 6%) (p < 0 center dot 001) however increased at an annual rate of 1 center dot 7%. Industry and Academic funding were negatively associated with race/ethnicity reporting (Industry adjusted odds ratio [aOR]: 0 center dot 42, 95% confidence interval [CI]: 0 center dot 38 to 0 center dot 46, p < 0.0001; Academic aOR: 0 center dot 45, CI: 0 center dot 41 to 0 center dot 50, p < 0.0001). Industry also had a negative association with the proportion of minority ethnicity enrollees (aOR: 0 center dot 69, CI: 0 center dot 60 to 0 center dot 79) compared to US Government-funded trials. Interpretation Over the past two decades, the majority of US trials in ClinicalTrials.gov do not report race/ethnicity enrollment data, and minorities are underrepresented in trials with modest improvement over time.. Copyright (c) 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)