Reliability and validity of the Chinese version of the Oxford Knee Score in patients with knee osteoarthritis before total knee arthroplasty / 中华骨科杂志

ABSTRACT

Objective To evaluate the psychometric properties and the clinical feasibility of Chinese version of the Oxford Knee Score in patients with knee osteoarthritis before total knee arthroplasty.Methods One hundred and fourteen (91 females,23 males) preoperative patients with knee osteoarthritis were recruited.Internal consistency was tested using Cronbach's alpha coefficient,and dimensionality was evaluated using exploratory factor analysis.The correlations between the scale,namely,WOMAC,SF-8 and EQ-5D were used to determine construct validity.The floor and ceiling effects were also examined.Results The scale showed acceptable internal consistency (Cronbach's alpha=0.885) and demonstrated good convergent and divergent validity with the moderate to strong correlations between the scale and WOMAC (r=-0.80),the SF-8 physical component summary (r=0.65),and the EQ-5D usual activities (r=-0.41) and mobility (r=-0.35).Moreover,the strong correlation between the scale and the SF-8 mental component summary (r=0.58),as well as the moderate correlation between the scale and the EQ-5D anxiety/depression (r=-0.35) were observed.Divergent construct validity was supported by weak correlation between the scale and EQ-5D VAS (r=0.30).The exploratory factor analysis yielded three factors with eigenvalues ＞ 1,accounting for 66.02％ of the variance.All items had factor loadings above 0.4.Factor 1 closely relates to physical function,while factor 2 depicts pain associated with knee osteoarthritis.Factor 3 had only one item (item 8),reflecting the patient's sleep problems.No sign of floor or ceiling effect was found.Conclusion Chinese version of the Oxford Knee Score is proven to be a reliable,valid scale for knee osteoarthritis patients before total knee arthroplasty.