The design and feasibility of a web-based physical activity program for patients with osteoarthritis in hip and/or knee.

Background: A large proportion of patients with osteoarthritis (OA) do not meet the recommended levels of physical activity (PA). Although inactivity may enhance in short-term pain reduction, prolonged inactivity may augment functional decline. Therefore, we developed a web-based intervention that provides a highly individualized behaviourally based physical activity program for patients with hip and/or knee OA. Objective: The aim of this study is to describe the systematic development process, a pilot study and the usability of a 9-week web-based intervention on PA behaviour change in individuals with hip and/or knee OA. Methods: An iterative design approach was used to develop, test and enhance various prototypes. End-users (i.e. patients with knee and/hip OA) were involved continuously throughout the development process. The intervention incorporates core principles of the behaviour graded activity theory. A pilot study prototype was tested through a non-randomized pilot study among 20 patients with hip and/or knee OA. PA levels, pain scores and physical function were measured through online questionnaires (week 0, 6 and 12). Subsequently, two usability methods (heuristic evaluation and a thinking aloud approach) were applied to determine the usability of the intervention. Results: After several iterations of testing and revising, we developed the final version, entitled as Artrose In Beweging (AIB). The program includes an introduction module (module 1) and 8 text based week assignments (module 2). OA patients, between 50 and 80 years of age, participated in the pilot study and received the intervention. After 12 weeks, there was a non-significant increase in PA (1697 to 2044 minutes per week). After six weeks, pain scores increased from 5.3 to 6.6 (p=0.04). After 12 weeks, however, this significant increase disappeared. Considering physical function, a non-significant small increase was observed. Although participants were enthusiastic about the web-based intervention, users perceived difficulties to login and completing the entire introduction module. Furthermore, users rated the rigid character of the intervention, i.e. the inability edit and undo executed actions, as annoying. Based on 16 the interviews after the pilot study, we adjusted the functions into a more flexible format. Conclusion: This paper outlines the preliminary effectiveness, development and usability of a web-based PA intervention. The results suggest that the intervention is feasible in promotion of PA among patients with hip and/or knee OA. The intervention was easy to use and the satisfaction with the program was high. Preliminary results from the pilot study revealed that PA scores increased, although differences were not statistical significant. Pain scores increased significantly after six week and decreased to baseline values after twelve weeks. Findings require validation in other studies. Therefore, the intervention will be further tested in a one year randomized controlled trial. (aut. ref.)