title: Feasibility, validity and reliability of the Welsh version of the EQ-5D health status questionnaire.
abstract: The feasibility, reliability and validity of a Welsh version of the EQ-5D health-related quality of life questionnaire were evaluated by means of a postal questionnaire administered on two occasions to a sample of adults across Welsh-speaking areas of Wales. The absolute response rate was 126 (out of 1,000), though after considering language and expected response to Welsh language questionnaires, the adjusted response rate was 50%. Respondents' mean age was 56.8 +/- 18 years and 38.7% reported having chronic illness. The number of missing items from the descriptive EQ-5D (aggregated for both administrations) was 4, representing 0.33% of all responses. Five EQ-VAS responses were returned incomplete. 97 (85.8%) respondents reported no change in health in the fortnight between the first and second administration. The Spearman rank coefficients for these respondents were 0.828 for EQ-5D scores, and 0.815 for EQ-VAS, respectively (both P < 0.000). Construct validity was confirmed by the power of the EQ-5D to discriminate between those expected to be healthy or otherwise, as assessed by self-reported health, presence of chronic illness, receipt of treatment, and age (all P < 0.0001). It is concluded that the Welsh version of the EQ-5D is both valid and reliable for measuring health status in subjects across Wales.
authors.affiliation: Centre for Economics and Policy in Health, Institute of Medical and Social Care Research, University of Wales, Bangor, Dean Street, Gwynedd, North Wales, LL57 1UT, UK. d.a.hughes@bangor.ac.uk
authors.forename: Dyfrig A
authors.initials: DA
authors.lastname: Hughes
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005240:Feasibility Studies; D005260:Female; D006304:Health Status; D006305:Health Status Indicators; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D011581:Psychological Tests; D011594:Psychometrics; D011788:Quality of Life / Q000523:psychology*; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D014852:Wales