title: Hospital variation in carotid stenting outcomes.
abstract: OBJECTIVE
  The aim of this study was to examine variation in outcomes for patients receiving carotid artery stenting (CAS) across a sample of U.S. hospitals and assess the extent to which this variation was attributable to differences in case mix and procedural volume.
  
  
  BACKGROUND
  As CAS is increasingly being used throughout the United States, assessing hospital variation in CAS outcomes is critical to understanding and improving the quality of care for patients with carotid artery disease.
  
  
  METHODS
  Hospitals participating in the National Cardiovascular Data Registry-Carotid Artery Endarterectomy and Revascularization Registry contributing more than 5 CAS procedures from 2005 through 2013 were eligible for inclusion. We estimated unadjusted and risk-standardized rates of in-hospital stroke or death for each participating hospital using a previously validated prediction model and applying hospital-level random effects.
  
  
  RESULTS
  There were 188 hospitals contributing 19,381 CAS procedures during the period of interest. Unadjusted and risk-standardized in-hospital stroke or death rates ranged from 0% to 18.8% and 1.2% to 4.7%, respectively. Operator and hospital volumes were not significant predictors of outcomes after adjustment for case mix (p = 0.15 and p = 0.09, respectively).
  
  
  CONCLUSIONS
  CAS outcomes vary 4-fold among hospitals, even after adjustment for differences in case mix. Future work is needed to identify the sources of this variation and develop initiatives to improve patient outcomes.
authors.affiliation: Cardiovascular Section, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
authors.forename: Beau M
authors.initials: BM
authors.lastname: Hawkins
authors.affiliation: Saint Luke's Mid-America Heart Institute/University of Missouri-Kansas City, Kansas City, Missouri.
authors.forename: Kevin F
authors.initials: KF
authors.lastname: Kennedy
authors.affiliation: St. Joseph Mercy Hospital-Michigan Heart Division, Ann Arbor, Michigan.
authors.forename: Herbert D
authors.initials: HD
authors.lastname: Aronow
authors.affiliation: Department of Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Louis L
authors.initials: LL
authors.lastname: Nguyen
authors.affiliation: John Ochsner Heart and Vascular Institute, Ochsner Medical Center, New Orleans, Louisiana.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: White
authors.affiliation: Division of Cardiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Rosenfield
authors.affiliation: Department of Health Care Policy (Biostatistics), Harvard Medical School, Boston, Massachusetts.
authors.forename: Sharon-Lise T
authors.initials: ST
authors.lastname: Normand
authors.affiliation: Saint Luke's Mid-America Heart Institute/University of Missouri-Kansas City, Kansas City, Missouri.
authors.forename: John A
authors.initials: JA
authors.lastname: Spertus
authors.affiliation: Division of Cardiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts. Electronic address: ryeh@mgh.harvard.edu.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Yeh
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017130:Angioplasty / Q000009:adverse effects / Q000295:instrumentation* / Q000401:mortality / Q000639:trends*; D002340:Carotid Artery Diseases / Q000150:complications / Q000175:diagnosis / Q000401:mortality / Q000628:therapy*; D005260:Female; D017052:Hospital Mortality; D061847:Hospitals, High-Volume / Q000639:trends*; D061846:Hospitals, Low-Volume / Q000639:trends*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010818:Practice Patterns, Physicians' / Q000639:trends*; D017064:Process Assessment, Health Care / Q000639:trends*; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D015607:Stents; D020521:Stroke / Q000209:etiology; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States
keywords: carotid stenosis; carotid stenting; hospital quality; stroke