Abstract 319: Hospital Variation in Carotid Artery Stenting Outcomes: An NCDR® Analysis

Abstract

Introduction: Given the increased use and dissemination of carotid artery stenting (CAS) throughout the United States, examining hospital-level variation in patient outcomes can form the foundation of quality improvement efforts. We examined hospital variation for in-hospital stroke and death (S/D) rates to examine the potential of such an outcome to serve as a performance measure of hospital quality. Methods: Hospitals participating in the CARE Registry ® contributing >5 CAS procedures from 2005-2012 were eligible for inclusion. We estimated risk-standardized rates of in-hospital S/D for each participating hospital using a previously validated prediction model and applying hospital-level random effects. Observed-expected (O/E) ratios were generated for each hospital by comparing rates of observed and expected S/D. Outliers were identified as facilities with O/E ratios whose confidence intervals excluded 1.0. Results: There were 173 hospitals contributing 15,683 CAS procedures during the period of interest. Risk-standardized rates of S/D ranged from 1.2% to 5.3%. Mean procedural volumes were low irrespective of hospital performance (procedures per quarter: 6.1 +/- 5.7 for hospitals with O/E >1.2, 9.4 +/- 9.1 for hospitals with O/E <0.8). Only 2 hospitals had risk-adjusted outcomes worse than expected, while 3 hospitals performed better than expected (Figure 1). Conclusions: Though substantial variation in CAS outcomes exists, wide confidence intervals resulting from low event rates and low hospital volumes prevent risk-adjusted outcomes from being a sensitive discriminator of performance for most hospitals. The development of additional performance measures may be needed to gauge CAS quality.