The usability and preliminary effectiveness of a web-based physical activity intervention in patients with knee and/or hip osteoarthritis

Background: A large proportion of patients with knee and/or hip osteoarthritis (OA) do not meet the recommended levels of physical activity (PA). Therefore, we developed a web-based intervention that provides a tailored PA program for patients with knee and/or hip OA, entitled Join2move. The intervention incorporates core principles of the behaviour graded activity theory (BGA). The aim of this study was to investigate the preliminary effectiveness, feasibility and acceptability of Join2move in patients with knee and/or hip OA. Methods: A non-randomized pilot study was performed among patients with knee and/or hip OA. Primary outcomes were PA (SQUASH Questionnaire), physical function (HOOS and KOOS questionnaires) and self-perceived effect (7-point Likert scale). Baseline, 6 and 12 week follow-up data were collected via online questionnaires. To assess feasibility and acceptability, program usage (modules completed) and user satisfaction (SUS questionnaire) were measured as secondary outcomes. Participants from the pilot study were invited to be interviewed. The interviews focused on users' experiences with Join2move. Besides the pilot study we performed two usability tests to determine the feasibility and acceptability of Join2move. In the first usability test, software experts evaluated the website from a list of usability concepts. In the second test, users were asked to verbalize thoughts during the execution of multiple tasks. Results: Twenty OA patients with knee and/or hip OA between 50 and 80 years of age participated in the pilot study. After six weeks, pain scores increased from 5.3 to 6.6 (p=0.04). After 12 weeks this difference disappeared (p=0.5). Overall, users were enthusiastic about Join2move. In particular, performing exercise at one's own pace without time or travel restrictions was cited as convenient. However, some minor flaws were observed. Users perceived some difficulties in completing the entire introduction module and rated the inability to edit and undo actions as annoying. Conclusions: This paper outlines the preliminary effectiveness, feasibility and acceptability of a web-based PA intervention. Preliminary results from the pilot study revealed that PA scores increased, although differences were not statistically significant. Interviews and usability tests suggest that the intervention is feasible and acceptable in promoting PA in patients with knee and/or hip OA. The intervention was easy to use and the satisfaction with the program was high.