Divergence and Convergence of Sex-Specific Time Trends in Ischemic Stroke: 10-Year Analysis of a State-Wide Registry in Germany

Background The incidence of ischemic stroke was previously expected to rise among countries with an aging population. Lately, several studies from developed countries have reported a decline in certain cohorts. Whether this applies to all sexes, however, is uncertain, with limited data on the temporal development in incidence, treatment, and recovery. Methods and Results We analyzed a prospective stroke inpatient quality-assurance registry of the federal state of Hesse, Germany. Recruitment of all patients with a final diagnosis of ischemic stroke at hospital discharge (International Classification of Diseases, Tenth Revision [ICD-10]: I63) is mandatory by law. Incidence rates were calculated based on census data of all inhabitants and stratified according to age. Between 2010 and 2019, there were 141 277 patients included, 73 770 (52.2%) male patients and 67 507 (47.8%) female patients. Overall, the incidence of ischemic stroke was 228 per 100 000 in 2010 and 226 per 100 000 in 2019 (-0.8%; odds ratio [OR], 0.99 [95% CI, 0.96-1.02]; P=0.50). For male patients, the incidence increased continuously from 236 per 100 000 to 245 per 100 000 (+3.8%); in female patients it decreased from 220 per 100 000 to 208 per 100 000 (-5.6%). After adjusting for age, the OR for ischemic stroke between male and female patients was 1.40 in 2010 (95% CI, 1.35-1.44; P<0.001) and 1.48 in 2019 (95% CI, 1.43-1.53; P<0.001). This development was most pronounced in male patients aged 45 to 59 years with an increase from 151 per 100 000 to 176 per 100 000. In this age group, male patients showed increasing rates of prior strokes and atrial fibrillation, surpassing the prevalence in female patients over time. After multivariable regression analysis, male patients had a lower modified Rankin Scale at discharge compared with female patients, but this difference has decreased since 2015 (common OR in 2010, 0.83 [95% CI, 0.78-0.88]; common OR in 2019, 0.90 [95% CI, 0.84-0.95]), which coincided with rising rates of endovascular treatment. Conclusions Over the past decade in the federal state of Hesse, the overall incidence of ischemic stroke has declined predominantly in the female population. In contrast, for male patients, the incidence has risen by about 4%, with a steeper increase of 16% in male patients aged 45 to 59 years, which might be related to increasing rates of recurrent strokes and atrial fibrillation in this cohort. This finding provides a cautionary tale for effective secondary prevention. Female patients were generally less likely to achieve a favorable outcome, but since the introduction of endovascular treatment, the outcome gap is decreasing.