Identifying Minimal and Meaningful Change in a Patient-Reported Outcomes Measurement Information System for Rheumatoid Arthritis: Use of Multiple Methods and Perspectives

Objective: Rheumatoid arthritis (RA) is chronic, painful, disabling condition resulting in significant impairments in physical, emotional, and social health. Our objective was to use different methods and perspectives to evaluate the responsiveness of Patient-Reported Outcomes Measurement Information System (PROMIS) short forms (SFs) and to identify minimal and meaningful score changes. Methods: Adults with RA who were enrolled in a multisite prospective observational cohort completed PROMIS physical function, pain interference, fatigue, and participation in social roles/activities SFs, the PROMIS 29-item form (PROMIS-29), and pain and patient global assessment, and rated change in specific symptoms and RA (a little versus lot better or worse) at the second visit. Physicians recorded joint counts, physician global assessment, and change in RA at visit 2. We compared mean score differences for minimal and meaningful improvement/worsening using patient and physician change ratings and distribution-based methods, and we visually inspected empirical cumulative distribution function curves by change categories. Results: The 348 adults were mostly female (81%) with longstanding RA. Using patient ratings, generally 1–3-point differences were observed for minimal change and 3–7 points for meaningful change. Larger differences were observed with patient versus physician ratings and for symptom-specific versus RA change. Mean differences were similar among SF versions. Prespecified hypotheses about change in PROMIS physical function, pain interference, fatigue, and participation and legacy scales were supported. Conclusion: PROMIS SFs and the PROMIS-29 profiles are responsive to change and generally distinguish between minimal and meaningful improvement and worsening in key RA domains. These data add to a growing body of evidence demonstrating the robust psychometric properties of PROMIS and supporting its use in RA care, research, and decision-making.