BackgroundUnderrepresentation of racial and ethnic minorities in clinical trials could worsen disparities but reporting and enrollment practices in nephrology randomized clinical trials have not been described.MethodsPubMed was searched to capture randomized clinical trials for five kidney disease-related conditions published between 2000-2021 in ten high impact journals. We excluded trials with less than 50 participants and pilot trials. Outcomes of interest were the proportion of trials reporting race and ethnicity and the proportions of enrolled participants in each race and ethnicity category.ResultsAmong 380 trials worldwide, race was reported in just over half and ethnicity in 12%. Most enrolled participants were White, and Black individuals accounted for ≤10% of participants except in dialysis trials where they accounted for 26% of subjects. However, Black participants were enrolled at high proportions relative to disease and population prevalence in US CKD, dialysis, and transplant trials representing 19% of participants in acute kidney injury, 26% in chronic kidney disease, 44% in glomerulonephritis, 40% in dialysis, and 26% in transplant trials. Enrollment of Asian participants was low worldwide except in glomerulonephritis trials with marked underrepresentation in US CKD, dialysis, and transplant trials. Hispanic individuals represented only 13% of participants in US dialysis trials compared with 29% of US dialysis population.ConclusionMore complete reporting of race and ethnicity in nephrology trials is needed. Black and Hispanic patients are well-represented in kidney disease trials in the United States. Asian patients are poorly represented in kidney trials both globally and in the US.Copyright © 2023 by the American Society of Nephrology.