Associations of Social, Behavioral, and Clinical Factors With Sex Differences in Stroke Recurrence and Poststroke Mortality

Background: Few population-based studies have assessed sex differences in stroke recurrence. In addition, contributors to sex differences in recurrence and poststroke mortality, including social factors, are unclear. We investigated sex differences in these outcomes and the contribution of social, clinical, and behavioral factors to the sex differences.

Methods: First-ever ischemic stroke cases identified from 2008 to 2019 from the population-based Brain Attack Surveillance in Corpus Christi Project in Texas were included and followed for recurrence and all-cause mortality through 2020. Sex differences in outcomes with and without adjustment for potential confounding factors, including social, behavioral, and clinical factors, were examined using Cox proportional hazard models. Factors that changed the log hazard ratio (HR) for sex by at least 10% after adjustment were identified as confounders/contributors. Final models were adjusted for all identified confounders.

Results: Of 2326 participants (mean age, 68 years; 48% women; 57% Mexican American), over median follow-ups of 5.4 years for recurrence and 3.7 years for mortality, 274 recurrences and 965 deaths occurred. No significant sex differences in recurrence were noted in unadjusted (HR, 0.89 [95% CI, 0.70-1.13]), age-adjusted (HR, 0.92 [95% CI, 0.72-1.18]), or fully adjusted models (HR, 0.88 [95% CI, 0.67-1.16]). Although women had a higher crude mortality rate than men (HR, 1.22 [95% CI, 1.08-1.38]), this sex difference disappeared after age adjustment (HR, 0.91 [95% CI, 0.80-1.03]). Other factors contributing to the sex difference included education, marital status, prestroke depression, health behaviors, initial stroke severity, prestroke disability, comorbidities, atrial fibrillation, and coronary artery disease. After simultaneously adjusting for all identified confounders, women had lower poststroke mortality (HR, 0.79 [95% CI, 0.68-0.91]).

Conclusions: Sex differences in stroke recurrence were not apparent. Women had a higher unadjusted poststroke mortality rate but lower adjusted mortality than men. Social and psychosocial factors, alongside clinical factors, primarily explained the sex disparity in poststroke mortality.