title: Modelling the cost-effectiveness of carotid endarterectomy for asymptomatic stenosis.
abstract: BACKGROUND
  The aim of this study was to model the cost-effectiveness of carotid endarterectomy for asymptomatic stenosis versus medical therapy based on 10-year data from the Asymptomatic Carotid Surgery Trial (ACST).
  
  
  METHODS
  This was a cost-utility analysis based on clinical effectiveness data from the ACST with UK-specific costs and stroke outcomes. A Markov model was used to calculate the incremental cost-effectiveness ratio (ICER, or cost per additional quality-of-life year) for a strategy of early endarterectomy versus medical therapy for the average patient and published subgroups. An exploratory analysis considered contemporary event rates.
  
  
  RESULTS
  The ICER was £7584 per additional quality-adjusted life-year (QALY) for the average patient in the ACST. At thresholds of £20,000 and £30,000 there was a 74 and 84 per cent chance respectively of early endarterectomy being cost-effective. The ICER for men below 75 years of age was £3254, and that for men aged 75 years or above was £71,699. For women aged under 75 years endarterectomy was less costly and more effective than medical therapy; for women aged 75 years or more endarterectomy was less effective and more costly than medical therapy. At contemporary perioperative event rates of 2·7 per cent and background any-territory stroke rates of 1·6 per cent, early endarterectomy remained cost-effective.
  
  
  CONCLUSIONS
  In the ACST, early endarterectomy was predicted to be cost-effective in those below 75 years of age, using a threshold of £20,000 per QALY. If background any-territory stroke rates fell below 1 per cent per annum, early endarterectomy would cease to be cost-effective.
authors.affiliation: Academic Section of Vascular Surgery, Imperial College London, London, UK. a.thapar09@imperial.ac.uk
authors.forename: A
authors.initials: A
authors.lastname: Thapar
authors.forename: L
authors.initials: L
authors.lastname: Garcia Mochon
authors.forename: D
authors.initials: D
authors.lastname: Epstein
authors.forename: J
authors.initials: J
authors.lastname: Shalhoub
authors.forename: A H
authors.initials: AH
authors.lastname: Davies
mesh_terms: D000368:Aged; D058070:Asymptomatic Diseases / Q000191:economics* / Q000628:therapy; D016893:Carotid Stenosis / Q000191:economics* / Q000601:surgery; D003362:Cost-Benefit Analysis; D016894:Endarterectomy, Carotid / Q000191:economics*; D005260:Female; D006801:Humans; D008297:Male; D008390:Markov Chains; D018803:Models, Economic; D011788:Quality of Life; D019057:Quality-Adjusted Life Years; D018570:Risk Assessment / Q000379:methods; D020521:Stroke / Q000191:economics / Q000517:prevention & control