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

Abstract

OBJECTIVE: To compare risks, subtypes, and hospitalization costs of stroke between cohorts with and without systemic lupus erythematosus (SLE). METHODS: 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. RESULTS: 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). CONCLUSION: 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.