Representation of Women in Stroke Clinical Trials Women account for less than half of all subjects enrolled in National Institutes of Health funded stroke prevention clini- cal drug trials of the past decade. It has also been recognized that women have been underrepresented in clinical trials in surgery, overall CVD, and cancer.400 403 Sex disparities in cerebrovascular disease clinical trial participation have been less well examined.404 The low proportion of women in clini- cal stroke prevention trials limits the generalization of results across the sexes. Conventional subgroup analyses in women are commonly flawed by type II error. As a result, it remains unclear whether current evidence-based practices apply to women, who represent half of all stroke victims. In response to recognition that overall, women were under- represented in National Institutes of Health sponsored trials, the National Institutes of Health Revitalization Act (public law 103-43), which required inclusion of women in clinical trials of diseases affecting women, was enacted in 1993.402,405 Unfortunately, to date, the legislation appears to have had little impact. A review of articles published in The New England Journal of Medicine after enactment of the legislation reported that there was no change in the overall rate of enrollment of females, which remained at roughly 25%.406 Neurological clinical trials were among the most successful in enrolling women, with a participation rate of 45%. A subsequent review of National Institutes of Health funded studies found that only 24% of enrolled drug study populations were women.400 This lack of recruitment continues in recent trials. 