Just One Move: co-design and usability testing of a digital physical activity behavior change platform for people with rheumatoid arthritis

Introduction Rheumatoid Arthritis (RA) affects 18 million people worldwide, leading to debilitating symptoms and increased cardiovascular disease risk. Regular physical activity can address these challenges, yet people with RA face barriers to physical activity and lack tailored support. Digital interventions offer a resource-efficient strategy for increasing physical activity. To improve their effectiveness and implementation, stronger end-user engagement and behavioral science integration is needed. Alongside physical activity experts, rheumatology providers, and people with RA, we completed preparatory research to inform the co-design of an RA-specific digital physical activity intervention: JustOneMove.ca. The present study presents learnings from the co-design process, outlines the resultant intervention, and summarizes usability survey findings. Methods The study leveraged patient-oriented research, user-centered design, and behavioral science frameworks (behavior change wheel, theoretical domains framework). After mapping physical activity barriers to these frameworks, Just One Move was co-designed via a 4-step user-centered process (Phase 1). We collaborated with people with RA and web design experts to review, design, refine, and develop the intervention using design sprint methodology. Data on resources required and partner involvement during Phase 1 were summarized descriptively. A mixed methods survey (Phase 2) gathered perspectives on usability and usefulness. Data were analyzed using descriptive statistics and qualitative content analysis. Results Co-design was completed in 7 months by a team of 20 people with RA, 5 researchers (rheumatology, physiotherapy, behavioral science), and 2 experts in healthcare design and web development. Co-design blended research evidence and user preferences through design thinking. Challenges included balancing creativity with feasibility and defining clear expectations. The Just One Move intervention includes: a library of RA-friendly movements, a guided action planner, a collection of inspiring stories from people with RA, and an expert toolkit with tips for moving well with RA. Across 37 users (median age: 62.0), average usability was 4.0/5 and usefulness was 3.7/5. Just One Move was easy to use and inspired confidence to move more. However, users requested clearer instructions and more customizable content. Conclusion Evidence-informed co-design can produce high-quality digital physical activity interventions for people with RA. Future work will examine the effectiveness of JustOneMove.ca.