Remote Monitoring for Rheumatoid Arthritis Flare During Drug Tapering: Protocol for a Prospective Observational Cohort Study.

Background: Rheumatoid arthritis (RA) disease activity during disease-modifying antirheumatic drug (DMARD) tapering is commonly monitored using in-person clinical assessment and the 28-joint Disease Activity Score with C-reactive protein (DAS28-CRP). Although effective, this approach is resource intensive and may be inconvenient for patients. Remote monitoring with patient-reported outcomes and wearable sensors may enable earlier flare detection and support safer, more personalized tapering pathways. Prior pilot work suggests that accelerometry-derived physical activity, mobility, and sleep metrics correlate with RA disease activity and are acceptable to patients. Objective: This protocol aims to evaluate the feasibility and diagnostic accuracy of remote monitoring for detecting RA flare during DMARD tapering. The study will (1) continuously measure physical activity and quality metrics using wrist-worn accelerometers, (2) collect weekly Rheumatoid Arthritis Flare Questionnaire (RA-FQ) scores, (3) develop and evaluate dynamic risk prediction models using longitudinal accelerometry-derived measurements to estimate the risk of clinically confirmed flare, (4) retrospectively assess prediction accuracy against patient-reported flare, and (5) develop and evaluate a combined dynamic prediction model incorporating longitudinal accelerometry-derived measurements and total RA-FQ scores to assess whether the addition of the RA-FQ improves the prediction of clinically confirmed flare. Methods: This prospective, single-center observational cohort study is embedded within the Rheumatoid Arthritis DMARD Tapering (ROADMAP) clinic at Freeman Hospital, Newcastle upon Tyne, United Kingdom. Adults with clinician-confirmed RA in remission who are undergoing or are about to begin DMARD tapering will be recruited, with a target sample of 100 participants. Participants will be followed for 12 months, with clinical assessments aligned with routine ROADMAP visits at baseline and approximately months 3, 6, 9, and 12 together with ad hoc visits for suspected flare. Continuous wrist-worn accelerometry and weekly RA-FQ responses will be collected throughout follow-up. Clinical assessments will include tender and swollen joint counts, patient and physician visual analog scales, C-reactive protein, the DAS28-CRP, and Health Assessment Questionnaire Disability Index scores. The primary outcome is time to first clinically confirmed flare, defined as DAS28-CRP≥2.4 and/or at least 1 swollen joint attributable to inflammatory RA activity. Dynamic risk prediction methods, such as landmarking models, will use longitudinal accelerometry-derived physical activity, mobility, gait, and sleep measures to estimate flare risk over prespecified prediction horizons. Model performance will be assessed using time-dependent discrimination, calibration, predictive values, and lead time before clinically confirmed flare. Results: The first participant was recruited in October 2025. As of July 2026, 16 participants had been recruited. This protocol reports the study design and planned analyses; outcome analyses will be conducted after recruitment and 12-month follow-up are complete. Conclusions: This study will provide pilot evidence on the feasibility and accuracy of multimodal remote monitoring for RA flare detection during DMARD tapering in routine care. Findings will inform model refinement, external validation, and future larger multicenter studies evaluating clinical utility and service impact.