title: Reliability, validity and responsiveness of the EQ-5D in assessing and valuing health status in patients with social phobia.
abstract: OBJECTIVE
  The aim of the study was to analyse the psychometric properties of the EQ-5D in patients with social phobia.
  
  
  METHODS
  We used a sample of 445 patients with social phobia with five measurement points over a 30 month period. The discriminative ability of the EQ-5D was analysed by comparing the patients' responses with the general population and between different disease severity levels. For test-retest reliability we assessed the level of agreement in patients' responses over time, when there was no change in the Liebowitz Social Anxiety Scale (LSAS). Construct validity was analysed by identifying correlations of the EQ-5D with more specific instruments. For responsiveness we compared the means of EQ VAS/EQ-5D index anchored on improved (deteriorated) health status and computed effect sizes as well as a receiver operating characteristic (ROC) curve.
  
  
  RESULTS
  Compared to the general population, patients with social phobia reported more problems in the dimensions "usual activities", "pain/discomfort", and "anxiety/depression" and less problems in "mobility" and "self-care". The EQ-5D was able to distinguish between different disease severity levels. The test-retest reliability was moderate (intraclass correlation coefficient > 0.6). Correlations between the EQ-5D and other instruments were mostly small except for correlations with Beck Depression Inventory. The EQ-5D index seemed to be more responsive than the EQ VAS, but with only medium effect sizes (0.5 < effect size < 0.8) in the British EQ-5D index and only significant in patients with improved health status. The ROC analysis revealed no significant results.
  
  
  CONCLUSIONS
  The EQ-5D was moderately reliable and responsive in patients with improved health status. Construct validity was limited.
  
  
  BACKGROUND
  Current controlled trials ISRCTN53517394.
authors.affiliation: Department of Health Economics and Health Services Research, Hamburg Center for Health Economics, University Medical Center Hamburg-Eppendorf, Martinistr, 52, 20246 Hamburg, Germany. mi.sonntag@uke.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Sonntag
authors.forename: Alexander
authors.initials: A
authors.lastname: Konnopka
authors.forename: Falk
authors.initials: F
authors.lastname: Leichsenring
authors.forename: Simone
authors.initials: S
authors.lastname: Salzer
authors.forename: Manfred E
authors.initials: ME
authors.lastname: Beutel
authors.forename: Stephan
authors.initials: S
authors.lastname: Herpertz
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Hiller
authors.forename: Jürgen
authors.initials: J
authors.lastname: Hoyer
authors.forename: Peter
authors.initials: P
authors.lastname: Joraschky
authors.forename: Björn
authors.initials: B
authors.lastname: Nolting
authors.forename: Karin
authors.initials: K
authors.lastname: Pöhlmann
authors.forename: Ulrich
authors.initials: U
authors.lastname: Stangier
authors.forename: Bernhard
authors.initials: B
authors.lastname: Strauss
authors.forename: Ulrike
authors.initials: U
authors.lastname: Willutzki
authors.forename: Jörg
authors.initials: J
authors.lastname: Wiltink
authors.forename: Eric
authors.initials: E
authors.lastname: Leibing
authors.forename: Hans-Helmut
authors.initials: HH
authors.lastname: König
mesh_terms: D000328:Adult; D005260:Female; D005858:Germany; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D010698:Phobic Disorders / Q000523:psychology*; D011788:Quality of Life / Q000523:psychology*; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires / Q000592:standards*; D055815:Young Adult