The course of limitations in activities over 5 years in patients with knee and hip osteoarthritis with moderate functional limitations: risk factors for future functional decline.

OBJECTIVE: To describe the course of limitations in activities over 5 years follow-up and identify predictors of future limitations in activities in elderly patients with osteoarthritis (OA) of the hip or knee with moderate functional limitations.
METHOD: A longitudinal cohort study with 5 years follow-up was conducted. Patients (n=288) were recruited at rehabilitation centers and hospitals. The main outcome measures were self-reported and performance-based limitations in activities. Prognostic factors were demographic and clinical data, body functions, comorbidity, cognitive functioning, avoidance of activity and social support. Measurements were conducted at baseline, 1, 2, 3 and 5 years follow-up.
RESULTS: Both in patients with knee and hip OA, the course of limitations in activities remained fairly stable over a period of 5 years. Avoidance of activity, increased pain, more comorbidity, a higher age, a longer disease duration, a reduced muscle strength and range of joint motion at baseline predicted more future limitations in activities in patients with knee OA. In patients with hip OA, avoidance of activity, increased pain, more comorbidity, a higher age, a higher educational level and a reduced range of motion at baseline predicted more future limitations in activities.
CONCLUSIONS: The course of limitations in activities remains fairly stable over a period of 5 years in elderly patients with hip or knee OA. However, at individual level there is considerable variation. Predictors of more future limitations in activities include avoidance of activity, increased pain, higher morbidity count, reduced range of motion, and a higher age.