Sources of hospital-level variation in functional outcome after acute ischemic stroke: a multicenter retrospective cohort study

Background Functional recovery is an important clinical outcome for patients with stroke. Hospital-level variation occurs in functional outcome after stroke. However, the extent to which patient characteristics, hospital characteristics, process of care, and medication persistence contribute to the hospital variation in poor functional outcome after ischemic stroke is unknown in China. Methods We retrospectively analyzed patients enrolled in the Third China National Stroke Registry from 2015 to 2018. The outcome was poor functional outcome (modified Rankin Scale score of 3-6) at 3 months and 1 year. We used the median odds ratio to quantify the hospital-level variation in rates of poor functional outcome. A series of hierarchical logistic models were constructed to assess the extent to which patient characteristics, hospital characteristics, process of care, and medication persistence contributed to the hospital variation. Results A total of 13,218 patients with acute ischemic stroke from 159 hospitals were included. The riskadjusted rates of the poor functional outcome at 3 months and 1 year after ischemic stroke varied across hospitals, ranging from 6.0% to 26.0% and 6.8% to 24.0%, respectively. The median odds ratio was 1.78 at 3 months and 1.67 at 1 year. Hierarchical logistic models indicated that the patient characteristics, hospital characteristics, process of care, and the medication persistence explained 27.5%, 7.0%, 6.5%, and 5.0% of the variation at 1 year. Altogether, 36.8% and 46.1% of the hospital variation in 3-month and 1-year poor functional outcome, respectively, was explained. Conclusions There was a wide variation in rates of functional outcomes across hospitals. Approximately half of the variation at 1 year can be explained by patient characteristics, hospital characteristics, process of care, and medication persistence. Approximately 11.5% of the variation can be modified through improvements in the process of care and medication persistence. More studies are needed to explore the contribution of post-discharge care in the future.