Age- and Sex-Specific Analysis of Stroke Hospitalization Rates, Risk Factors, and Outcomes From German Nationwide Data

BACKGROUND: Significant age and sex differences have been reported at each stage of the stroke pathway, from risk factors to outcomes. However, there is some uncertainty in previous studies with regard to the role of potential confounders and selection bias. Therefore, using German nationwide administrative data, we aimed to determine the magnitude and direction of trends in age- or sex-specific differences with respect to admission rates, risk factors, and acute treatments of ischemic and hemorrhagic stroke. METHODS: We obtained and analyzed data from the Research Data Centres of the Federal Statistical Office for the years 2010 to 2020 with regard to all acute stroke hospitalizations, risk factors, treatments, and in-hospital mortality, stratified by sex and stroke subtype. This database provides a complete national-level census of stroke hospitalizations combined with population census counts. All hospitalized patients >= 15 years with an acute stroke (diagnosis code: I60-64) were included in the analysis. RESULTS: Over the 11-year study period, there were 3 375 157 stroke events; 51.2% (n=1 728 954) occurred in men. There were higher rates of stroke admissions in men compared with women for both ischemic (378.1 versus 346.7/100 000 population) and hemorrhagic subtypes (75.6 versus 65.5/100 000 population) across all age groups. The incidence of ischemic stroke admissions peaked in 2016 among women (354.0/100 000 population) and in 2017 among men (395.8/100 000 population), followed by a consistent decline from 2018 onward. There was a recent decline in hemorrhagic stroke admissions observed for both sexes, reaching its nadir in 2020 (68.9/100 000 for men; 59.5/100 000 for women). Female sex was associated with in-hospital mortality for both ischemic (adjusted odds ratio, 1.11 [1.09-1.12]; P<0.001) and hemorrhagic stroke (adjusted odds ratio, 1.18 [95% CI, 1.16-1.20]; P<0.001). CONCLUSIONS: Despite improvements in stroke prevention and treatment pathways in the past decade, sex-specific differences remain with regard to hospitalization rates, risk factors, and mortality. Better understanding the mechanisms for these differences may allow us to develop a sex-stratified approach to stroke care.