Chinese adaptation and validation of the Knee Injury and Osteoarthritis Outcome Score (KOOS) in patients with knee osteoarthritis

Knee Injury and Osteoarthritis Outcome Score (KOOS) is a commonly used instrument to assess the symptoms and functional status in people with knee injuries, including knee osteoarthritis. While China ranked the top country in the absolute number of people aged 65 or above, yet there is no validated Chinese version of this outcome measurement. This study translated and validated the KOOS into Chinese version. Chinese KOOS was translated from the original English version following standard forward and backward translation procedures recommended by the International Society for Pharmacoeconomics and Outcomes Research. Survey was then conducted in clinical settings by a questionnaire comprised Chinese KOOS, WOMAC Osteoarthritis Index, and Short Form 36 health survey (SF-36). One hundred Chinese reading patients with knee osteoarthritis were recruited from the orthopaedic out-patient department in hospitals. Internal consistency of the instrument was measured by Cronbach alpha. Construct validity was examined by Spearman’s rank correlation coefficient (ρ) tests by comparing its score with the validated Chinese version of WOMAC Osteoarthritis Index and SF-36, while the test–retest reliability was evaluated by administering the questionnaires twice. Cronbach alpha values of individual questions and its overall value were above 0.70. Fairly strong association was found between the Chinese KOOS and the WOMAC Osteoarthritis Index (ρ = −0.37 to −0.86, p < 0.001). Diverse relationship was observed between Chinese KOOS and SF-36. Excellent test–retest reliability (ICC = 0.89–0.92) was demonstrated. The Chinese translated version of KOOS is a reliable and valid instrument for patients with knee osteoarthritis. The findings of current study might promote multinational investigations in this patient group.