Analysis of participant race and sex reporting and disparities in US epilepsy clinical trials

Objective: Studies have shown that a growing number of people with epilepsy belong to minority groups and experience health disparities. Inclusivity in clinical trial enrollment is essential for advancing health access but has not been well studied among epilepsy trials. The objective of this study was to analyze US epilepsy clinical trials to identify the prevalence and trends associated with race and sex enrollment disparities.

Methods: We queried the Clinicaltrials.gov registry to identify completed epilepsy clinical trials with results reported between 2006 and 2022. Studies were assessed for reporting of participant race and sex information, and measures of trial diversity including the participation to prevalence ratio (PPR), representation ratio (RR), and representation quotient (RQ) were calculated. Other data including funding source, intervention type, location, and trial dates were also extracted.

Results: Ninety trials met inclusion criteria, of which 89 (99%) and 53 (59%) reported participant sex and race, respectively. Three trials included only female participants and were excluded from further sex-specific analyses. Females were underrepresented in 10 of the remaining 86 trials reporting sex information (PPR < .8, 12%). We found that industry-funded trials were more likely to have equal female representation among participants (p = .0197). Of trials reporting participant race, 52 (98%) exhibited a lack of racial diversity (RQ < 1). Black participants were the most frequently underrepresented racial group (RR < 1, 42 of 53 trials, 79%).

Significance: Our findings highlight significant disparities in epilepsy clinical trial enrollment, particularly for Black participants. Lack of diversity and underrepresentation of historically marginalized populations may contribute to research biases and perpetuate health inequities. More inclusive research practices are needed to ensure all people with epilepsy have access to effective care.