Chinese translation and validation of the Oxford Knee Scale for patients with knee osteoarthritis

BACKGROUND: Oxford Knee Scale (OKS) is a commonly used instrument to assess the symptoms and functional status in people with knee osteoarthritis. However, a Chinese version of this scale is not yet available. OBJECTIVE: The objective of this study was to translate the OKS into Chinese and validate the Chinese version of OKS. METHODS: The Chinese OKS was translated from the original English version following the recommendations of the International Society for Pharmacoeconomics and Outcomes Research. One hundred Chinese reading patients with knee osteoarthritis were recruited from local hospitals and physiotherapy clinics. Psychometric properties were evaluated in terms of test–retest reliability and internal consistency. Convergent validity was examined by Spearman rank correlation coefficient tests by comparing its score with the validated Chinese version of the Western Ontario and McMaster Universities Osteoarthritis Index and Health Outcome Survey Short Form-36. RESULTS: Chinese OKS demonstrated excellent reliability (intraclass correlation coefficient = 0.88). Cronbach α of individual questions was > 0.7. Strong correlation was found between the Chinese OKS and the Western Ontario and McMaster Universities Osteoarthritis Index (ρ > 0.553, p < 0.001). Fairly strong negative correlation was also found between Chinese OKS and Health Outcome Survey Short Form-36 (ρ = −0.273 to −0.666, p < 0.05). CONCLUSION: The Chinese translated version of OKS is a reliable and valid instrument for clinical evaluation in Chinese reading patients with knee osteoarthritis.