title: CT angiography is cost-effective for confirmation of internal carotid artery occlusions.
abstract: OBJECTIVE
  While sensitive to internal carotid artery (ICA) occlusion, carotid ultrasound can produce false-positive results. CT angiography (CTA) has a high specificity for ICA occlusion and is safer and cheaper than catheter angiography, although less accurate. We determined the cost-effectiveness of CTA versus catheter angiography for confirming an ICA occlusion first suggested by carotid ultrasound.
  
  
  METHODS
  A Markov decision-analytic model was constructed to estimate the cost-effectiveness of CTA compared with catheter angiography in a hypothetical cohort of symptomatic patients with a screening examination consistent with an ICA occlusion. Costs in 2004 dollars were estimated from Medicare reimbursement. Effectiveness was measured in quality-adjusted life years.
  
  
  RESULTS
  The 2-year cost in the CTA scenario was $9,178, and for catheter angiography, $11,531, consistent with a $2,353 cost-savings per person for CTA. CTA resulted in accrual of 1.83 quality-adjusted life years while catheter angiography resulted in 1.82 quality-adjusted life years. CTA was less costly and marginally more effective than catheter angiography. In sensitivity analyses, when CTA sensitivity and specificity were allowed to vary across a plausible range, CTA remained cost-effective.
  
  
  CONCLUSIONS
  After screening examination has suggested an ICA occlusion, confirmatory testing with CTA provides similar effectiveness to catheter angiography and is less costly.
authors.affiliation: Stroke Program, University of Michigan, Ann Arbor, MI 48109-5855, USA. devinb@umich.edu
authors.forename: Devin L
authors.initials: DL
authors.lastname: Brown
authors.forename: Stuart N
authors.initials: SN
authors.lastname: Hoffman
authors.forename: Teresa L
authors.initials: TL
authors.lastname: Jacobs
authors.forename: Kirsten L
authors.initials: KL
authors.lastname: Gruis
authors.forename: Susan L
authors.initials: SL
authors.lastname: Johnson
authors.forename: Michael E
authors.initials: ME
authors.lastname: Chernew
mesh_terms: D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging* / Q000601:surgery; D016893:Carotid Stenosis / Q000000981:diagnostic imaging / Q000191:economics* / Q000401:mortality / Q000601:surgery; D002406:Catheterization, Peripheral / Q000191:economics*; D002533:Cerebral Angiography / Q000191:economics*; D002544:Cerebral Infarction / Q000000981:diagnostic imaging / Q000191:economics / Q000401:mortality; D003362:Cost-Benefit Analysis; D003661:Decision Support Techniques; D016894:Endarterectomy, Carotid; D017052:Hospital Mortality; D006760:Hospitalization / Q000191:economics; D006801:Humans; D008390:Markov Chains; D012306:Risk; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000191:economics*