title: Comparison of direct and indirect methods of estimating health state utilities for resource allocation: review and empirical analysis.
abstract: OBJECTIVE
  Utilities (values representing preferences) for healthcare priority setting are typically obtained indirectly by asking patients to fill in a quality of life questionnaire and then converting the results to a utility using population values. We compared such utilities with those obtained directly from patients or the public.
  
  
  METHODS
  Review of studies providing both a direct and indirect utility estimate.
  
  
  METHODS
  Papers reporting comparisons of utilities obtained directly (standard gamble or time tradeoff) or indirectly (European quality of life 5D [EQ-5D], short form 6D [SF-6D], or health utilities index [HUI]) from the same patient.
  
  
  METHODS
  PubMed and Tufts database of utilities.
  
  
  METHODS
  Sign test for paired comparisons between direct and indirect utilities; least squares regression to describe average relations between the different methods.
  
  
  METHODS
  Mean utility scores (or median if means unavailable) for each method, and differences in mean (median) scores between direct and indirect methods.
  
  
  RESULTS
  We found 32 studies yielding 83 instances where direct and indirect methods could be compared for health states experienced by adults. The direct methods used were standard gamble in 57 cases and time trade off in 60(34 used both); the indirect methods were EQ-5D (67 cases), SF-6D (13), HUI-2 (5), and HUI-3 (37). Mean utility values were 0.81 (standard gamble) and 0.77 (time tradeoff) for the direct methods; for the indirect methods: 0.59(EQ-5D), 0.63 (SF-6D), 0.75 (HUI-2) and 0.68 (HUI-3).
  
  
  CONCLUSIONS
  Direct methods of estimating utilities tend to result in higher health ratings than the more widely used indirect methods, and the difference can be substantial.Use of indirect methods could have important implications for decisions about resource allocation: for example, non-lifesaving treatments are relatively more favoured in comparison with lifesaving interventions than when using direct methods.
authors: Cardiff University Medical School,Cardiff.
authors: David
authors: D
authors: Arnold
authors: Alan
authors: A
authors: Girling
authors: Andrew
authors: A
authors: Stevens
authors: Richard
authors: R
authors: Lilford
mesh_terms: D000328:Adult; D003362:Cost-Benefit Analysis; D003625:Data Collection / Q000379:methods; D003627:Data Interpretation, Statistical; D017048:Health Care Costs / Q000706:statistics & numerical data; D006305:Health Status Indicators; D006801:Humans; D011788:Quality of Life; D040841:Resource Allocation; D012306:Risk