Sex differences in mortality and functional outcomes across stroke subtype: A nationwide cohort study

BACKGROUND: Sex disparities in stroke outcomes are well-recognized, but it remains unclear whether these disparities vary across stroke subtypes and how they relate to differences in acute care delivery. AIM: The aim of the study was to examine sex differences in long-term mortality, functional outcomes, and acute stroke management across stroke subtypes using a nationwide population-based cohort. METHODS: This retrospective cohort study analyzed linked clinical audit and claims data from 58,429 patients with acute stroke admitted to 269 hospitals in South Korea between 2018 and 2021. Clinical data were derived from the national Acute Stroke Quality Assessment Program and linked to claims. The primary outcome was all-cause mortality. The secondary outcome was poor functional outcome at discharge. Multivariable Cox and logistic regression models were used to assess associations between sex and outcomes, stratified by stroke subtype and adjusted for age, stroke severity, and comorbidities. Differences in acute stroke care were also analyzed. RESULTS: Of 58,429 patients (mean [SD] age, 68.6 [13.8] years; 43.9% female), 76.1% had ischemic stroke (IS), 15.7% intracerebral hemorrhage (ICH), and 8.2% subarachnoid hemorrhage (SAH). Females were older than males across all subtypes and had different comorbidity profiles. After adjustment, females had significantly lower mortality in all subtypes (adjusted hazard ratios [95% CI]: IS, 0.77 [0.74-0.80]; ICH, 0.60 [0.56-0.64]; SAH, 0.60 [0.54-0.67]; all P < 0.001). Functional outcomes varied: females had worse outcomes in IS, better in ICH, and no difference in SAH. Males were more likely to receive reperfusion and surgical therapies; females were more likely to receive rehabilitation services. These care differences did not fully explain the observed disparities in outcomes. CONCLUSION: In this national cohort, sex disparities in stroke outcomes differed by subtype. Despite lower adjusted mortality in females, functional outcomes were not uniformly better. These findings underscore the importance of adopting sex- and subtype-specific approaches to stroke care, secondary prevention, and rehabilitation.