Objective: To determine the effect of patient exercise adherence within the prescribed physical therapy treatment period and after physical therapy discharge on patient outcomes of pain, physical function, and patient self-perceived effect in individuals with osteoarthritis (OA) of the hip and/or knee.
Methods: We performed a prospective observational followup study in which 150 patients with OA of the hip and/or knee receiving exercise therapy were followed for 60 months. Data were obtained from a randomized controlled trial, with assessments at baseline and 3, 15, and 60 months of followup. The association between exercise adherence and patient outcomes of pain, physical function, and self-perceived effect was examined using generalized estimating equations analyses.
Results: Adherence to recommended home exercises and being more physically active were significantly associated with better treatment outcomes of pain, self-reported physical function, physical performance, and self-perceived effect. The association between adherence and outcome was consistent over time. Adherence to home activities was only associated with better self-perceived effect.
Conclusion: Better adherence to recommended home exercises as well as being more physically active improves the long-term effectiveness of exercise therapy in patients with OA of the hip and/or knee. Both within and after the treatment period, better adherence is associated with better patient outcomes of pain, physical function, and self-perceived effect. Since exercise adherence declines over time, future research should focus on how exercise behavior can be stimulated and maintained in the long term.