title: Cost-effectiveness of diagnostic strategies prior to carotid endarterectomy.
abstract: The main objective of this study was to assess the long-term cost-effectiveness of five alternative diagnostic strategies for identification of severe carotid stenosis in recently symptomatic patients. A decision-analytical model with Markov transition states was constructed. Data sources included a prospective study involving 167 patients who had screening Doppler ultrasound (DUS), confirmatory contrast-enhanced magnetic resonance angiography (CEMRA) and confirmatory digital subtraction angiography (DSA), individual patient data from the European Carotid Surgery Trial and other published clinical and cost data. A "selective" strategy, whereby all patients receive DUS and CEMRA (only proceeding to DSA if the CEMRA is positive and the DUS is negative), was most cost-effective. This was both the cheapest imaging and treatment strategy (35,205 dollars per patient) and yielded 6.1590 quality-adjusted life years (QALYs), higher than three alternative imaging strategies. Probabilistic sensitivity analysis demonstrated that there was less than a 10% probability that imaging with either DUS or DSA alone are cost-effective at the conventional 50,000 dollars/QALY threshold. In conclusion, DSA is not cost-effective in the routine diagnostic workup of most patients. DUS, with additional imaging in the form of CEMRA, is recommended, with a strategy of "CEMRA and selective DUS review" being shown to be the optimal imaging strategy.
authors.affiliation: Department of Radiology, Addenbrooke's Hospital and the University of Cambridge, Cambridge, United Kingdom.
authors.forename: Jean Marie
authors.initials: JM
authors.lastname: U-King-Im
authors.forename: William
authors.initials: W
authors.lastname: Hollingworth
authors.forename: Rikin A
authors.initials: RA
authors.lastname: Trivedi
authors.forename: Justin J
authors.initials: JJ
authors.lastname: Cross
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Higgins
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Graves
authors.forename: Sergei
authors.initials: S
authors.lastname: Gutnikov
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Kirkpatrick
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Warburton
authors.forename: Nagui M
authors.initials: NM
authors.lastname: Antoun
authors.forename: Peter M
authors.initials: PM
authors.lastname: Rothwell
authors.forename: Jonathan H
authors.initials: JH
authors.lastname: Gillard
mesh_terms: D000368:Aged; D016893:Carotid Stenosis / Q000175:diagnosis* / Q000191:economics* / Q000601:surgery; D016022:Case-Control Studies; D003362:Cost-Benefit Analysis; D016894:Endarterectomy, Carotid / Q000379:methods; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000191:economics / Q000379:methods; D008297:Male; D008390:Markov Chains; D015588:Observer Variation; D011237:Predictive Value of Tests; D011300:Preoperative Care / Q000191:economics*; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000191:economics / Q000379:methods; D018616:Ultrasonography, Doppler, Duplex / Q000191:economics / Q000379:methods