title: Estimating health utilities in patients with asthma and COPD: evidence on the performance of EQ-5D and SF-6D.
abstract: OBJECTIVE
  The objective of this study was to understand systematic differences in utility values derived from the EQ-5D and the SF-6D in two respiratory populations with heterogeneous disease severity.
  
  
  METHODS
  This study involved secondary analysis of data from two cross-sectional surveys of patients with asthma (N = 228; Hungary) and COPD (N = 176; Sweden). Disease severity was defined according to GINA and GOLD guidelines for asthma and COPD, respectively. EQ-5D and SF-6D scores and their distributional characteristics were compared across the two samples by disease severity level.
  
  
  RESULTS
  Within each patient population, mean EQ-5D and SF-6D scores were similar for the overall group and for those with moderate disease. Mean scores varied for patients with mild and severe disease. EQ-5D versus SF-6D scores in the asthma group by severity levels were 0.89 versus 0.80, 0.70 versus 0.73, 0.63 versus 0.64, and 0.51 versus 0.63, respectively. EQ-5D versus SF-6D scores in the COPD group by severity levels were 0.85 versus 0.80, 0.73 versus 0.73, 0.74 versus 0.73, and 0.53 versus 0.62, respectively.
  
  
  CONCLUSIONS
  Results suggest the EQ-5D and SF-6D do not yield consistent utility values in patients with asthma and COPD due to differences in underlying valuation techniques and the EQ-5D's limited response options relative to mild disease.
authors.affiliation: Covance Market Access Services Inc., Springfield House, Hyde Street, Leeds, LS2 9LH, UK. agota.szende@covance.com
authors.forename: A
authors.initials: A
authors.lastname: Szende
authors.forename: N K
authors.initials: NK
authors.lastname: Leidy
authors.forename: E
authors.initials: E
authors.lastname: Ståhl
authors.forename: K
authors.initials: K
authors.lastname: Svensson
mesh_terms: D001249:Asthma / Q000503:physiopathology* / Q000523:psychology*; D003430:Cross-Sectional Studies; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D008875:Middle Aged; D011594:Psychometrics / Q000379:methods*; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology* / Q000523:psychology*; D011795:Surveys and Questionnaires