Demographic Reporting and Representation Among Neurosurgical Clinical Trials in the United States

The purpose of this study is to evaluate trends in the reporting and representation of sex, race, and ethnicity across neurosurgical clinical trials.

A comprehensive analysis of U.S. neurosurgical clinical trials registered on ClinicalTrials.gov was conducted in August 1, 2025. A total of 317 completed neurosurgical clinical trials with posted results were included. Trials were categorized by neurosurgical subspecialty, sponsorship, phase, sample size, study period, and age eligibility. The primary outcomes were reporting and representation of sex, race, and ethnicity. Wilcoxon signed-rank tests and paired t-tests were conducted to assess representation compared to the annual state census demographic data. Linear and multivariate regressions were conducted to assess temporal trends and trial characteristics' influence over representation and reporting.

Among 317 neurosurgical clinical trials, the mean participant age was 50 years. Sex, race, and ethnicity were reported in 99%, 38%, and 26%, respectively. White and non-Hispanic participants were consistently overrepresented compared with the state-level census, while minority races and ethnicities tended to be underrepresented across nearly all neurosurgical subspecialties. Reporting of race and ethnicity increased significantly over time, but overall reporting rates remained low.

Despite improvements in reporting over time, neurosurgical clinical trials demonstrate persistently low reporting of race/ethnicity and tend to have underrepresentation of racial and ethnic minority populations over all clinical trials and certain subspecialties. These findings highlight ongoing gaps in demographic transparency and inclusivity, supporting efforts toward more standardized reporting and broader participant representation in neurosurgical research.