To determine the effectiveness of exercise therapy in patients with osteoarthritis (OA) of the hip or knee.
A randomized single blind, clinical trial was conducted in a primary care setting. Patients with hip or knee OA by American College of Rheumatology criteria were selected. Two intervention groups were compared. Both groups received treatment from the patients' general practitioner, including patient education and medication if necessary. The experimental group also received exercise therapy from a physiotherapist in primary care. The treatment period was 12 weeks. The main outcome measures were pain, medication use (nonsteroidal antiinflammatory drugs, NSAID) and observed disability.
A total of 201 patients were randomized. Exercise therapy was associated with a reduction of pain in the past week (difference in change -17.0; 95% CI -23.6, -10.4) and observed disability (-0.19; 95% CI -0.38; -0.01). Effect sizes were medium (0.58) and small (0.28), respectively. No effect of exercise therapy was found for the use of NSAID. Additional beneficial effects (p = 0.05) were found for the use of paracetamol (effect size 0.33), global effect as perceived by the patient (effect size 0.68), and muscle strength of the hip (effect size 0.34).
After 12 weeks, exercise therapy is effective in reducing pain and disability. The size of the effects is medium and small, respectively.