The purpose of this cross sectional study was to estimate the contributions of patient characteristics to variation in joint-specific and generic health status in knee osteoarthritis (OA) patients referred for physical therapy.
The Portuguese Knee injury and Osteoarthritis Outcome Score (KOOS) and Medical Outcomes Study - 36 item Short Form (SF-36) questionnaires, and a form for the patient characteristics (gender, age, body mass index, profession, professional situation, educational level, marital status, duration of knee OA, involved knee and walking aids) were self-administered to 377 subjects with symptomatic knee OA (282 females, 95 males; age: 67.8 ± 8.2 years).
Multiple stepwise regression analyses revealed that patient characteristics explained only 9.4% to 19.7% of the variance in KOOS subscales scores, and only 1.0% to 17.2% of the variance in SF-36 subscales scores.
Therefore, it can be concluded that the patient characteristics studied were limited predictors of joint-specific and generic health status in knee OA patients referred for physical therapy.