Stroke Recurrence Following 28 Days After First Stroke in Men and Women 2012 to 2020: Observations From the Swedish Stroke Register.

Background Stroke incidence, care, and survival show continuous improvements in Sweden, including no or decreasing disparities between men and women. In this study, we aimed to estimate and compare the risk of stroke recurrence in men and women over time, accounting for the competing risk of death. Methods and Results We included adult patients with first-time stroke (ischemic or intracerebral hemorrhage) registered in Riksstroke (the Swedish Stroke Register), 2012 to 2020, and followed until December 2020. Stroke recurrences included new events registered in Riksstroke from 28 days after stroke. To account for the competing risk of death, we used the cumulative incidence function to estimate crude incidences, and multivariable Cox regression to estimate cause-specific hazard ratios (HRs) adjusting for differences in patients' risk factor profiles. The study included 72 148 (53.5%) men and 62 689 (46.5%) women. We observed 10 925 stroke recurrences and 81 811 deaths following the initial 28 days after the first stroke. The cumulative incidence of stroke recurrence was 3.7% (95% CI, 3.6-3.8) after 1 year, 7.0 (95% CI, 6.8-7.1) after 3 years, and 9.1% (95% CI, 8.9-9.3) after 5 years. The incidence decreased substantially during the study period (HR, 2019-2020 versus 2012, 0.824 [95% CI, 0.759-0.894]). Overall, men had a lower risk of stroke recurrence. After adjustments for differences in patient characteristics, men had a slightly higher risk of recurrence (of any type) after an ischemic stroke (HR, 1.090 [95% CI, 1.045-1.138]) and a lower risk after hemorrhagic stroke (HR, 0.880 [95% CI, 0.781-0.991]) compared with women. Conclusions The risk of stroke recurrence has decreased in both men and women. Women's higher age and other differences in risk factors partly explain their higher risk of stroke recurrence compared with men.