Racial and ethnic representation in systemic sclerosis clinical trials: a 25-year analysis of ClinicalTrials.gov...

This study aimed to quantify reporting of race and ethnicity in systemic sclerosis (SSc) clinical trials, characterise geographic distribution, and assess participant representation relative to US population benchmarks.

We conducted a cross-sectional analysis of registered SSc trials with enrolment data. Of 699 trials screened, 95 met initial criteria; after excluding 21 terminated and 4 non-SSc studies, 70 completed trials (n = 4956 participants) were analysed. We summarised the prevalence of race/ethnicity reporting and calculated race/ethnicity distributions among participants with available data. US Census estimates were used for contextual comparison. Trials were also grouped by recruiting continent.

Among 70 trials, 39 (55.7%) reported race and 26 (37.1%) reported ethnicity; 25 reported both, while 30 (42.9%) reported neither. Participant-level data were available for 3161 individuals for race (60.0% of all enrollees) and 2255 for ethnicity (47.1%). Among those with race reported, 78.5% were White (n = 2482), 12.7% Asian (n = 400), 4.9% Black or African American (n = 155), 1.4% multiracial (n = 45), 0.6% American Indian/Alaska Native (n = 18), and 0.3% Native Hawaiian/Other Pacific Islander (n = 8); 1.7% were unknown/unreported (n = 53). Of participants with ethnicity data (n = 2335), 10.9% were Hispanic/Latino, 86.6% not Hispanic/Latino, and 2.5% unknown/unreported. Trial activity was concentrated in North America (39.2%) and Europe (36.3%), with additional activity in Asia (16.6%); South America, Oceania, and Africa contributed smaller shares.

Race/ethnicity reporting in SSc trials is incomplete, and available data reveal disproportionate underenrolment of Black and Hispanic/Latino participants relative to US population benchmarks. Standardised reporting and intentional, equity-focused recruitment are needed to enhance representativeness and interpretability of SSc trial findings.