Sex Differences in the Epidemiology of Intracerebral Hemorrhage Over 10 Years in a Population‐Based Stroke Registry

Background: We investigated incidence and outcome of spontaneous intracerebral hemorrhage (ICH) in a population-based stroke registry and provided data to inform on the figures of the disease in women and in men. Methods and results: Our prospective population-based registry included patients with first-ever ICH occurring from January 2011 to December 2020. Incidence rates were standardized to the 2011 Italian and European population, and incidence rate ratios were calculated. Multivariate hazard ratios for 30-day and 1-year fatality were estimated with Cox regression, including components of the ICH score and sex. We included 748 first-ever ICHs (41.3% women). Women were significantly older than men at ICH onset (78.9±12.6 versus 73.2±13.6 years; P<0.001) and showed higher clinical severity on presentation (median National Institutes of Health Stroke Scale score, 11 [interquartile range, 6-20] versus 9 [interquartile range, 4-15], respectively; P=0.016). The crude annual incidence rate was 20.2 (95% CI, 18.0-22.6) per 100 000 person-years in women and 30.2 (95% CI, 27.4-33.2) per 100 000 person-years in men); incidence was lower in women versus men (incidence rate ratio, 0.67 [95% CI, 0.58-0.78]; P<0.001) and did not change over time in both sexes (P for trend=0.073 and 0.904, respectively). Unadjusted comparison showed higher 1-year case-fatality rates in women versus men (48.5% versus 40.1%; P=0.026). After adjusting for components of the ICH score, female sex lost significance as a predictor of mortality. Conclusions: We found lower ICH incidence in women than in men. However, women showed a higher 1-year case-fatality rate versus men, which was likely related to older age at ICH onset and higher clinical severity. Identification of factors explaining the reported differences is important to develop targeted interventions.