title: Cost-effectiveness of angiographic imaging in isolated perimesencephalic subarachnoid hemorrhage.
abstract: OBJECTIVE
  The purpose of this study is to perform a comprehensive cost-effectiveness analysis of all possible permutations of computed tomographic angiography (CTA) and digital subtraction angiography imaging strategies for both initial diagnosis and follow-up imaging in patients with perimesencephalic subarachnoid hemorrhage on noncontrast CT.
  
  
  METHODS
  Each possible imaging strategy was evaluated in a decision tree created with TreeAge Pro Suite 2014, with parameters derived from a meta-analysis of 40 studies and literature values. Base case and sensitivity analyses were performed to assess the cost-effectiveness of each strategy. A Monte Carlo simulation was conducted with distributional variables to evaluate the robustness of the optimal strategy.
  
  
  RESULTS
  The base case scenario showed performing initial CTA with no follow-up angiographic studies in patients with perimesencephalic subarachnoid hemorrhage to be the most cost-effective strategy ($5422/quality adjusted life year). Using a willingness-to-pay threshold of $50 000/quality adjusted life year, the most cost-effective strategy based on net monetary benefit is CTA with no follow-up when the sensitivity of initial CTA is >97.9%, and CTA with CTA follow-up otherwise. The Monte Carlo simulation reported CTA with no follow-up to be the optimal strategy at willingness-to-pay of $50 000 in 99.99% of the iterations. Digital subtraction angiography, whether at initial diagnosis or as part of follow-up imaging, is never the optimal strategy in our model.
  
  
  CONCLUSIONS
  CTA without follow-up imaging is the optimal strategy for evaluation of patients with perimesencephalic subarachnoid hemorrhage when modern CT scanners and a strict definition of perimesencephalic subarachnoid hemorrhage are used. Digital subtraction angiography and follow-up imaging are not optimal as they carry complications and associated costs.
authors.affiliation: From the Department of Diagnostic Radiology, Yale School of Medicine, New Haven, CT (V.B.K., H.P.F., A.M.); and Timothy Dwight College, Yale University, New Haven, CT (X.W.).
authors.forename: Vivek B
authors.initials: VB
authors.lastname: Kalra
authors.affiliation: From the Department of Diagnostic Radiology, Yale School of Medicine, New Haven, CT (V.B.K., H.P.F., A.M.); and Timothy Dwight College, Yale University, New Haven, CT (X.W.).
authors.forename: Xiao
authors.initials: X
authors.lastname: Wu
authors.affiliation: From the Department of Diagnostic Radiology, Yale School of Medicine, New Haven, CT (V.B.K., H.P.F., A.M.); and Timothy Dwight College, Yale University, New Haven, CT (X.W.).
authors.forename: Howard P
authors.initials: HP
authors.lastname: Forman
authors.affiliation: From the Department of Diagnostic Radiology, Yale School of Medicine, New Haven, CT (V.B.K., H.P.F., A.M.); and Timothy Dwight College, Yale University, New Haven, CT (X.W.). ajay.malhotra@yale.edu.
authors.forename: Ajay
authors.initials: A
authors.lastname: Malhotra
mesh_terms: D015901:Angiography, Digital Subtraction / Q000191:economics*; D002533:Cerebral Angiography / Q000191:economics*; D003362:Cost-Benefit Analysis; D003663:Decision Trees; D006801:Humans; D009010:Monte Carlo Method; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging*
keywords: angiography; digital subtraction