title: Has evidence changed practice?: appropriateness of carotid endarterectomy after the clinical trials.
abstract: OBJECTIVE
  To assess how appropriateness of and indications for carotid endarterectomy (CEA) have changed following the publication of several large international randomized controlled trials (RCTs) designed to rationalize use of CEA.
  
  
  METHODS
  The New York Carotid Artery Surgery Study (NYCAS) is a population-based cohort study of all CEAs performed on elderly patients from January 1998 through June 1999 in New York State. Detailed clinical data were abstracted from medical charts to assess indications for and appropriateness of surgery using a list of 1,557 indications for CEA developed by national experts using RAND appropriateness methods. Deaths and strokes within 30 days of surgery were ascertained and confirmed by two physicians.
  
  
  RESULTS
  Among the 9,588 patients, the mean age was 74.6 years and 93.6% had 70 to 99% carotid stenosis. Nearly three-quarters of patients (72.3%) underwent CEA for asymptomatic stenosis, 18.6% for TIA, and 9.1% for stroke. Overall, 87.1% of operations were done for appropriate reasons, 4.3% for uncertain reasons, and 8.6% for inappropriate reasons (vs 32% inappropriate before the RCTs, p < 0.0001). Among procedures judged inappropriate, the most common reasons were high comorbidity in asymptomatic patients (62.2%), operating after a major stroke (14.2%), or for minimal stenosis (10.5%). Among asymptomatic patients, those with high comorbidity had over twice the risk of death or stroke compared to those without high comorbidity (7.13% vs 2.69%, p < 0.0001).
  
  
  CONCLUSIONS
  Since publication of the randomized controlled trials, there has been a reduction in the proportion of patients undergoing carotid endarterectomy (CEA) for inappropriate reasons. The shift toward many asymptomatic patients undergoing CEA is concerning because the net benefit from surgery for these patients is low and is reduced further for patients with high comorbidity.
authors.affiliation: Division of General Internal Medicine, Department of Health Policy, Mount Sinai School of Medicine, New York, NY 10029, USA. ethan.halm@mountsinai.org
authors.forename: E A
authors.initials: EA
authors.lastname: Halm
authors.forename: S
authors.initials: S
authors.lastname: Tuhrim
authors.forename: J J
authors.initials: JJ
authors.lastname: Wang
authors.forename: M
authors.initials: M
authors.lastname: Rojas
authors.forename: E L
authors.initials: EL
authors.lastname: Hannan
authors.forename: M R
authors.initials: MR
authors.lastname: Chassin
mesh_terms: D000368:Aged; D002340:Carotid Artery Diseases / Q000401:mortality* / Q000601:surgery*; D002986:Clinical Trials as Topic / Q000706:statistics & numerical data*; D016894:Endarterectomy, Carotid / Q000401:mortality*; D019317:Evidence-Based Medicine / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D009518:New York / Q000453:epidemiology; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D015995:Prevalence; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data*; D018570:Risk Assessment; D020521:Stroke / Q000401:mortality* / Q000517:prevention & control*; D015996:Survival Rate; D016896:Treatment Outcome