Impact of Stroke Center Certification on Mortality After Ischemic Stroke: The Medicare Cohort From 2009 to 2013

Abstract

Background and purpose: An increasing number of hospitals have been certified as primary stroke centers (PSCs). It remains unknown whether the action toward PSC certification has improved the outcome of stroke care. This study aimed to understand whether PSC certification reduced stroke mortality.

Methods: We examined Medicare fee-for-service beneficiaries aged ≥65 years who were hospitalized between 2009 and 2013 for ischemic stroke. Hospitals were classified into 3 groups: new PSCs, the hospitals that received initial PSC certification between 2009 and 2013 (n=634); existing PSCs, the PSCs certified before 2009 (n=785); and non-SCs, the hospitals that have never been certified as PSCs (n=2640). Multivariate logistic regression and Cox proportional hazards model was used to compare the mortality among the 3 groups.

Results: Existing PSCs were significantly larger than new PSCs as reflected by total number of beds and annual stroke admission (P<0.0001). Compared with existing PSCs, new PSCs had lower in-hospital (odds ratio, 0.862; 95% confidence interval [CI], 0.817-0.910) and 30-day mortality (hazard ratio [HR], 0.981; 95% CI, 0.968-0.993), after adjusting for patient demographics and comorbidities. Compared with non-SCs, new PSCs had lower adjusted in-hospital (odds ratio, 0.894; 95% CI, 0.848-0.943), 30-day (HR, 0.904; 95% CI, 0.892-0.917), and 1-year mortality (HR, 0.907; 95% CI, 0.898-0.915). Existing PSCs had lower adjusted 30-day (HR, 0.922; 95% CI, 0.911-0.933) and 1-year mortality (HR, 0.900; 95% CI, 0.892-0.907) than non-SCs.

Conclusions: Obtaining stroke certification may reduce stroke mortality and overcome the disadvantage of being smaller hospitals. Further study of other outcome measures will be useful to improve stroke system of care.

Keywords: ischemic stroke; mortality; outcome; primary stroke center; stroke center certification.