Sex Differences in the Participation in Secondary Prevention Stroke Studies

BACKGROUND: Women show higher age-standardized mortality rates for ischemic stroke. Nevertheless, women are underrepresented in secondary stroke prevention trials. Our analysis investigated contributors to reduced study participation among women in a comprehensive stroke center in Austria. METHODS: The population-based Tyrolean Stroke Pathway database was used to describe sex distribution in patients with ischemic stroke in the region and at the study site. Screening logs from 3 secondary stroke prevention studies at the Medical University of Innsbruck were analyzed containing information on age, self-reported sex, and causes for nonparticipation. Binary and multinomial logistic regression were performed to calculate odds ratios (ORs) and 95% CIs. RESULTS: Women constituted 45.6% of all patients with ischemic stroke in the federal region and 43.1% at the study site. Of 4511 patients screened, 68.1% were included in at least 1 stroke trial, 39.5% of whom were female. Screened women were older than screened men, median age (interquartile range) of 76 (66-83) versus 72 (61-80) years. Women showed higher odds than men of receiving comfort terminal care (OR, 1.53 95% CI, 1.14-2.05), being unable to provide informed consent (OR, 1.95 95% CI, 1.54-2.47) due to aphasia (OR, 2.79 95% CI, 1.91-4.06) or cognitive impairment (OR, 1.96 95% CI, 1.30-2.95), and being ineligible for study participation based on inclusion and exclusion criteria (OR, 1.28 95% CI, 1.04-1.58). When adjusting for age, women were not more likely than men to refuse study participation (OR, 1.09 95% CI, 0.84-1.43). CONCLUSIONS: Female sex was associated with higher odds of exclusion from studies due to comorbidities and more severe neurological deficits. However, in our analysis women were not more likely to refuse study participation.