title: Cross-cultural adaptation and validation of Singapore English and Chinese Versions of the Oxford Knee Score (OKS) in knee osteoarthritis patients undergoing total knee replacement.
abstract: OBJECTIVE
  To cross-culturally adapt and validate Singapore English and Chinese versions of the Oxford Knee Score (OKS) in patients with knee osteoarthritis (OA) undergoing total knee replacement (TKR) surgery.
  
  
  METHODS
  Singapore English and Chinese OKS versions were cross-culturally adapted from the source English version following standard guidelines (including cognitive debriefing), and validated by interviewing patients in English or Chinese using an identical, pretested questionnaire containing the OKS, Short Form 36, and EQ-5D. Reliability was assessed using Cronbach's alpha, dimensionality using principal component factor analysis and item-total correlations, convergent and divergent construct validity by assessing six and three a priori hypotheses, respectively.
  
  
  RESULTS
  The Singapore English and Chinese OKS were well accepted by patients in pilot testing. When administered to a consecutive sample of 127 English and 131 Chinese-speaking Singaporeans with knee OA (mean age 66 years, 83% female, mean duration of OA 6 years, Chinese:Malay:Indian:Others=78:7.9:11:3.1% for English version), Cronbach's alpha exceeded 0.8 and factor analysis yielded three factors for both versions. Hypothesized item-total correlations (Spearman's rho > or = 0.4) were observed for all items except limping, kneeling, and night knee pain in both versions. Convergent construct validity was supported by the presence of hypothesized moderate/strong correlations (rho=0.37-0.73) for six and five a priori hypotheses in English and Chinese versions, respectively. Divergent construct validity was supported by the presence of weak correlations (rho=0.09-0.30) for all three a priori hypotheses in both versions.
  
  
  CONCLUSIONS
  Singapore English and Chinese OKS demonstrated good patient acceptability and psychometric properties (including construct validity) among multiethnic Asian patients with knee OA undergoing TKR.
authors.affiliation: Centre for Health Services Research, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: F
authors.initials: F
authors.lastname: Xie
authors.forename: S-C
authors.initials: SC
authors.lastname: Li
authors.forename: N-N
authors.initials: NN
authors.lastname: Lo
authors.forename: S-J
authors.initials: SJ
authors.lastname: Yeo
authors.forename: K-Y
authors.initials: KY
authors.lastname: Yang
authors.forename: W
authors.initials: W
authors.lastname: Yeo
authors.forename: H-C
authors.initials: HC
authors.lastname: Chong
authors.forename: K-Y
authors.initials: KY
authors.lastname: Fong
authors.forename: J
authors.initials: J
authors.lastname: Thumboo
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000534:rehabilitation*; D001208:Asia / Q000208:ethnology; D003431:Cross-Cultural Comparison; D005260:Female; D006801:Humans; D008297:Male; D011594:Psychometrics; D011788:Quality of Life; D015203:Reproducibility of Results; D012846:Singapore / Q000453:epidemiology; D011795:Surveys and Questionnaires / Q000592:standards*; D016896:Treatment Outcome