Objective: Women have been under-represented in clinical trials areas of cardiovascular disease but there is less certainty over the level of disparity specifically in stroke. We examined the participation of women in trials according to stroke prevalence in the population.

Methods: Published randomized controlled trials with ≥100 participants enrolled between 1990 and 2020 were identified from ClinicalTrials.gov. To quantify sex disparites in enrolment we calculated the participation to prevalence ratio (PPR), defined as the percentage of women participating in a trial against the prevalence of women in the disease population.

Results: There were 281 stroke trials eligible for analyses with a total of 588,887 participants, of whom 37.4 % were women. Overall, women were represented at a lower proportion relative to their prevalence in the underlying population (mean PPR 0.84; 95% confidence interval [CI] (0.81 to 0.87)). The greatest differences were observed in trials of intracerebral hemorrhage (PPR 0.73; 95% CI 0.71 to 0.74), trials with a mean age of participants <70 years (PPR 0.81; 95% CI (0.78 to 0.84)), non-acute interventions (PPR 0.80; 95% CI (0.76 to 0.84)) and rehabilitation trials (PPR 0.77; 95% CI 0.71 to 0.83)). These findings did not significantly change over the period from 1990 to 2020 (p for trend = 0.201).

Conclusion: Women are disproportionately represented in stroke trials relative to the burden of disease in the population. Clear guidance and effective implementation strategies are required to improve the inclusion of women and thus broader knowledge of the impact of interventions in clinical trials.