Background Understanding of sex differences, especially in terms of the influence of sex on therapeutic interventions, can lead to improved treatment and management for all. Aim We examined temporal and regional trends in female participation and the reporting of sex differences in stroke randomized controlled trials. Methods Randomized controlled trials from 1990 to 2018 were identified from ClinicalTrials.gov, using keywords “stroke” and “cerebrovascular accidents.” Studies were selected if they enrolled ≥100 participants, included both sexes and were published trials (identified using PubMed, Google Scholar, and Scopus). Results Of 1700 stroke randomized controlled trials identified, 277 were published and eligible for analysis. Overall, these randomized controlled trials enrolled only 40% females, and in the past 10 years, this percentage barely changed, peaking at 41% in 2008–2009 and 2012–2013. North American randomized controlled trials recruited the most women, at 43%, and Asia the lowest, at 40%. Among the 277 randomized controlled trials, 101 (36%) reported results according to sex, of which 91 (33%) were pre-specified analyses. The increasing trend in the number of studies reporting sex-differentiated results from 2008 to 2018 merely paralleled the increase in the number of papers published during the same time period. North American randomized controlled trials most often reported sex-specific results (42%), and Australia and Europe least often (31%). Conclusion Little progress has been made in the inclusion of females and the reporting of sex in stroke randomized controlled trials. This highlights the need for key stakeholders, such as funders and journal editors, to provide clear guidance and effective implementation strategies to researchers in the scientific reporting of sex.

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 underrepresented 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.