title: A time-tradeoff method for cost-effectiveness models applied to radiology.
abstract: OBJECTIVE
  The wait tradeoff (WTO) is a simple time-tradeoff method designed for temporary health states that uses a realistic and intuitive interface for the patient/subject. This method was tested by assessing patients' preferences for magnetic resonance angiography (MRA) versus x-ray angiography (XRA).
  
  
  METHODS
  The WTO was tested by telephone interview in 38 patients with atherosclerotic peripheral vascular disease, all having previously undergone both MRA and XRA. At indifference point, patients were ambivalent about having MRA or XRA and immediate treatment, versus having a waiting period for test results and treatment after a hypothetical "ideal test" that entailed no pain or risk.
  
  
  RESULTS
  The patients were willing to wait a mean of 42.1 days after the ideal test for results and treatment, as opposed to XRA. They were willing to wait only 16.1 days as opposed to MRA. This difference in waiting times was significant (p = 0.0001) and indicates a clear preference for MRA, in agreement with known literature.
  
  
  CONCLUSIONS
  The WTO method assesses preferences for these radiologic tests in an intuitive fashion that does not invoke artificial or irrelevant health states. This approach may also prove useful for other testing situations or short-term treatments being evaluated for cost-effectiveness.
authors.affiliation: Department of Radiology, Indiana University, Indianapolis 46202, USA. jsswan@iupui.edu
authors.forename: J S
authors.initials: JS
authors.lastname: Swan
authors.forename: D G
authors.initials: DG
authors.lastname: Fryback
authors.forename: W F
authors.initials: WF
authors.lastname: Lawrence
authors.forename: F
authors.initials: F
authors.lastname: Sainfort
authors.forename: M E
authors.initials: ME
authors.lastname: Hagenauer
authors.forename: D M
authors.initials: DM
authors.lastname: Heisey
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000191:economics; D003362:Cost-Benefit Analysis; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000191:economics; D008297:Male; D008875:Middle Aged; D017059:Models, Econometric; D017060:Patient Satisfaction; D016491:Peripheral Vascular Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D019057:Quality-Adjusted Life Years; D013997:Time Factors; D014850:Waiting Lists