title: Which unruptured cerebral aneurysms should be treated? A cost-utility analysis.
abstract: OBJECTIVE
  To determine which unruptured cerebral aneurysms should be treated considering the risks. benefits, and costs.
  
  
  BACKGROUND
  Asymptomatic unruptured cerebral aneurysms are commonly treated by surgical clipping or endovascular coil embolization to prevent subarachnoid hemorrhage (SAH).
  
  
  METHODS
  We performed a cost-utility analysis comparing surgical clipping and endovascular coil embolization with no treatment for unruptured aneurysms. Eight clinical scenarios were defined based on aneurysm size, symptoms, and history of SAH from a different aneurysm. Health outcomes of a hypothetical cohort of 50-year-old women were modeled over the projected lifetime of the cohort. Costs were assessed from the societal perspective. We compared net quality-adjusted life years (QALYs) and cost per QALY of each therapy to no treatment.
  
  
  RESULTS
  For an asymptomatic unruptured aneurysm less than 10 mm in diameter in patients with no history of SAH from a different aneurysm, both procedures resulted in a net loss in QALYs, and confidence intervals (CI) were not compatible with a benefit from treatment (clipping, loss of 1.6 QALY [95% CI 1.1 to 2.1]; coiling, loss of 0.6 QALY [95% CI 0.2 to 0.8]). For larger aneurysms (> or = 10 mm), those producing symptoms by compressing neighboring nerves and brain structures, or in patients with a history of SAH from a different aneurysm, treatment was cost-effective. Coiling appeared more effective and cost-effective than clipping but these differences depended on relatively uncertain model parameters.
  
  
  CONCLUSIONS
  Treatment of small, asymptomatic, unruptured cerebral aneurysms in patients without a history of SAH worsens clinical outcomes, and thus is neither effective nor cost-effective. For aneurysms that are > or = 10 mm or symptomatic, or in patients with a history of SAH, treatment appears to be cost-effective.
authors.affiliation: Department of Neurology, University of California, San Francisco 94143-0114, USA. clayj@itsa.ucsf.edu
authors.forename: S C
authors.initials: SC
authors.lastname: Johnston
authors.forename: D R
authors.initials: DR
authors.lastname: Gress
authors.forename: J G
authors.initials: JG
authors.lastname: Kahn
mesh_terms: D003362:Cost-Benefit Analysis; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000191:economics*; D008297:Male; D008875:Middle Aged; D008959:Models, Neurological; D011788:Quality of Life; D012307:Risk Factors