title: Validity and reliability of the EQ-5D self-report questionnaire in English-speaking Asian patients with rheumatic diseases in Singapore.
abstract: Validity and reliability of a Singaporean English EQ-5D self-report questionnaire (EQ-5D) were evaluated among consecutive outpatients with rheumatic diseases attending a tertiary referral hospital in Singapore (a multi-ethnic, urban Asian country). Subjects were interviewed twice within a 2-week period using a standardized questionnaire containing the EQ-5D, Short Form 36 Health Survey (SF-36) and assessing demographic and psychosocial characteristics. To assess validity of the EQ-5D, 13 hypotheses relating responses to EQ-5D dimension/Visual Analogue Scale (EQ-VAS) to SF-36 scores or other variables were examined using the Mann-Whitney test, Kruskal-Wallis test, or Spearman's correlation coefficient. Test-retest reliability was assessed using Cohen's kappa. Sixty-six subjects were studied (osteoarthritis: 9, rheumatoid arthritis: 26, systemic lupus erythematosus: 23, spondyloarthropathy: 8; female: 72.7%; mean age: 44.3 years). Ten of 13 a-priori hypotheses relating EQ-5D responses to external variables were fulfilled, supporting the validity of the EQ-SD. Cohen's kappa for test-retest reliability (n = 52) ranged from 0.29 to 0.61. The Singaporean English EQ-5D appears to be valid in measuring quality of life in Singaporeans with rheumatic diseases; however, its reliability requires further investigation. These data provide a basis for further studies assessing the validity of the EQ-5D in Singapore.
authors.affiliation: Department of Pharmacy, National University of Singapore, Singapore.
authors.forename: N
authors.initials: N
authors.lastname: Luo
authors.forename: L H
authors.initials: LH
authors.lastname: Chew
authors.forename: K Y
authors.initials: KY
authors.lastname: Fong
authors.forename: D R
authors.initials: DR
authors.lastname: Koh
authors.forename: S C
authors.initials: SC
authors.lastname: Ng
authors.forename: K H
authors.initials: KH
authors.lastname: Yoon
authors.forename: S
authors.initials: S
authors.lastname: Vasoo
authors.forename: S C
authors.initials: SC
authors.lastname: Li
authors.forename: J
authors.initials: J
authors.lastname: Thumboo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008875:Middle Aged; D011594:Psychometrics; D011788:Quality of Life; D012216:Rheumatic Diseases / Q000523:psychology*; D020377:Self Efficacy; D018434:Sickness Impact Profile; D012846:Singapore; D011795:Surveys and Questionnaires