Risks, Subtypes, and Hospitalization Costs of Stroke Among Patients with Systemic Lupus Erythematosus: A Retrospective Cohort Study in Taiwan

Abstract

To compare risks, subtypes, and hospitalization costs of stroke between cohorts with and without systemic lupus erythematosus (SLE). From the catastrophic illnesses registry of Taiwan's universal health insurance claims data, we identified 13,689 patients with SLE diagnosed in 1997-2008 and selected 54,756 non-SLE controls, frequency-matched with age (every 5 years), sex, and index year. Age-specific and type-specific stroke incidence, hazard, and cost of stroke were compared between the 2 cohorts to the end of 2008. Compared with the non-SLE cohort, the risk of stroke was 3.2-fold higher in the SLE cohort (5.53 vs 1.74 per 1000 person-years) with an overall adjusted HR of 2.90 (95% CI 2.52-3.33). The age-specific risk was the highest in patients 1-17 years old (HR 163, 95% CI 22.2-1197) and decreased as age increased (p = 0.004). Hypertension and renal disease were the most important comorbidities in the SLE cohort predicting stroke risk (HR 1.75, 95% CI 1.28-2.39 and HR 1.66, 95% CI 1.32-2.10, respectively). There were more hemorrhagic strokes in the SLE cohort than in the non-SLE cohort, but not significantly (28.0% vs 23.4%; p = 0.10). The hospitalization cost for stroke patients was more than twice the cost for those with SLE than for those without (p < 0.0001). Stroke risk and hospital care costs are considerably greater for patients with SLE than without. The relative risk of stroke is the highest in young patients with SLE.