A Population-Based Study

Background: Ankylosing spondylitis (AS) is a chronic inflamma-tory arthritis affecting the spine in young adults. It is associated with excess cardiovascular and cerebrovascular morbidity. Objective: To determine whether patients with AS are at in-creased risk for cardiovascular and cerebrovascular mortality. Design: Population-based retrospective cohort study using ad-ministrative health data. Setting: Ontario, Canada. Patients: 21 473 patients with AS aged 15 years or older and 86 606 comparators without AS, matched for age, sex, and loca-tion of residence. Measurements: The primary outcome was a composite of car-diovascular and cerebrovascular death. Hazard ratios (HRs) for vascular death were calculated; adjusted for history of cancer, diabetes, dementia, inflammatory bowel disease, hypertension