Racial and ethnic diversity in global neuroscience clinical trials.

Background: Despite efforts to increase diversity in neuroscience trials, racial and ethnic minority groups remain underrepresented. Disparities in clinical trial participation could reflect unequal opportunities to participate and may contribute to decreased generalizability of findings and failure to identify important differences in efficacy and safety outcomes. Methods: We retrospectively reviewed the F. Hoffmann-La Roche database for global, multicenter, neuroscience clinical trials from February 2016 to February 2021 and summarized and stratified race and ethnicity distributions by clinical trial therapeutic area and by country. These data were then compared to national population data for each study's targeted age group (available for studies conducted in the US, Canada, and the UK). The underrepresentation or overrepresentation of each racial and ethnic group was summarized. Results: The analysis population included 8015 participants from 47 countries. Globally, 85.6 % of participants were White, 7.1 % were Asian, 1.6 % were Black, 1.3 % were American Indian or Alaska Native, less than 0.1 % were Native Hawaiian or other Pacific Islander, 0.7 % were of multiple races, and 3.6 % were of other/unknown race. White individuals predominated in all but one trial. Black individuals were underrepresented in all trials but one. Asian individuals were overrepresented in approximately 20 % of trials. In the US, 7.3 % of participants were of Hispanic or Latino ethnicity vs 16.4 % of the US population. Conclusion: The findings and learnings from this summary and analysis demonstrate the need for continued awareness and new approaches in designing studies that reflect population diversity.