Effects of a Self-directed Web-Based Strengthening Exercise and Physical Activity Program Supported by Automated Text Messages for People with Knee Osteoarthritis: A Randomized Clinical Trial

Abstract

Importance: Exercise therapies are advocated in osteoarthritis (OA) clinical guidelines. However, challenges to accessing exercise may be limiting widespread uptake. Objective: To evaluate the effects of a self-directed web-based strengthening exercise and physical activity program supported by automated behavior-change text messages on knee pain and function for people with knee OA. Design, Setting, and Participants: The participant-blinded and assessor-blinded randomized clinical trial enrolled 206 people who met clinical criteria for knee OA in communities across Australia from July 2018 to August 2019, with follow-up taking place at 24 weeks. Interventions: The control group was given access to a custom-built website with information on OA and the importance of exercise and physical activity. The intervention group was given access to the same information plus a prescription for a 24-week self-directed strengthening regimen and guidance to increase physical activity, supported by automated behavior-change text messages encouraging exercise adherence. Main Outcomes and Measures: Primary outcomes were change in overall knee pain (numeric rating scale, 0-10) and difficulty with physical function (Western Ontario and McMaster Universities Osteoarthritis Index, 0-68) over 24 weeks. Secondary outcomes were another knee pain measure, sport and recreation function, quality of life, physical activity, self-efficacy, overall improvement, and treatment satisfaction. Results: Of 206 participants, 180 (87%; mean [SD] age, 60 [8.4] years; 109 [61%] women) completed both 24-week primary outcomes. The intervention group showed greater improvements in overall knee pain (mean difference, 1.6 units; 95% CI, 0.9-2.2 units; P