Endometriosis as a Risk Factor for Ischemic and Hemorrhagic Stroke: A Population-Based Cohort Study

We completed a retrospective population-based cohort study using administrative data from Ontario female patients from 1993 to 2015 to examine the association between a diagnosis of endometriosis and stroke. We identified 166 853 female patients with a diagnosis of endometriosis and 333 706 unexposed female patients. Although the absolute risk of stroke was low, during the study period, 680 patients had ischemic stroke in the endometriosis group (28.2 cases per 100 000 person-years; 95% CI 26.1-30.4) and 1119 in the unexposed group (23.8 cases per 100 000 person-years; 95% CI 22.5-25.3)-adjusted hazard ratio 1.13 (95% CI 1.03-1.24). Confirmation of this association and consideration for clinical implications is warranted.