Examining variation in Medicare payments and drivers of cost for carotid endarterectomy.

BACKGROUND: There is a growing interest in providing high quality and low-cost care to Americans. A pursuit exists to measure not only how well hospitals are performing but also at what cost. We examined the variation in costs associated with carotid endarterectomy (CEA), to determine which components contribute to the variation and what drives increased payments.

MATERIALS AND METHODS: Patients undergoing CEA between 2009 and 2012 were identified in the Medicare provider and analysis review database. Hospital quintiles of cost were generated and variation examined. Multivariable logistic regression was performed to identify independent predictors of high-payment hospitals for both asymptomatic and symptomatic patients undergoing CEA.

RESULTS: A total of 264,018 CEAs were performed between 2009 and 2012; 250,317 were performed in asymptomatic patients in 2302 hospitals and 13,701 in symptomatic patients in 1851 hospitals. Higher payment hospitals had a higher percentage of nonwhite patients and comorbidity burden. The largest contributors to variation in overall payments were diagnosis-related groups, postdischarge, and readmission payments. After accounting for clustering at the hospital level, independent predictors of high-payment hospitals for all patients were postoperative stroke, length of stay, and readmission ,whereas in the symptomatic group, additional drivers included yearly volume and serious complications.

CONCLUSIONS: CEA Medicare payments vary nationwide with diagnosis-related group, readmission, and postdischarge payments being the largest contributors to overall payment variation. In addition, stroke, length of stay, and readmission were the only independent predictors of high payment for all patients undergoing CEA.