Diverging Trends in Survival and Functional Outcome between Males and Females after Intracerebral Hemorrhage

Background: Compared to ischemic stroke, sex differences in patient outcomes following intracerebral hemorrhage (ICH) are underreported. We aimed to determine sex differences in mortality and functional outcomes in a large, unselected Swedish cohort. Methods: In this observational study, data on 22,789 patients with spontaneous ICH registered in the Swedish Stroke Register between 2012 and 2019 were used to compare sex differences in 90-day mortality and functional outcome using multivariable Cox and logistic regression analyses, adjusting for relevant confounders. Multiple imputation was used to impute missing data. Results: The crude 90-day mortality rate was 36.7% in females (3,820/10,405) and 31.7% in males (3,929/12,384) (female hazard ratio [HR] 1.20 95% confidence interval [CI]: 1.15-1.25). In multivariable analysis, the HR for 90-day mortality following ICH in females was 0.89 (95% CI: 0.85-0.94). Age was an important driving factor for the effect of sex on mortality. After adjustment for age, vascular risk factors, and stroke severity, the 90-day functional outcome in pre-stroke independent patients was worse in females compared to males (odds ratio: 1.27 95% CI: 1.16-1.40). Conclusion: In this large observational study, despite lower 90-day mortality, the female sex was independently associated with a worse functional outcome compared to males after ICH, even after adjusting for significant covariates. These diverging trends have not been previously reported for ICH. Given the observational design, our findings should be interpreted with caution, thus further external validation is warranted.