Outcomes Reported in Prospective Long-Term Observational Studies and Registries of Patients With Rheumatoid Arthritis Worldwide: An Outcome Measures in Rheumatology Systematic Review

Objective Prospective long-term observational studies (LOS) in rheumatoid arthritis (RA) lack a core set of universally collected outcome measures, particularly patient-centered outcomes, precluding accurate comparisons across studies. Our aim was to identify long-term outcome measures collected and reported in these studies. Methods We conducted a systematic review of registries and LOS of patients with RA, searching in ClinicalTrials.gov, the Agency for Healthcare Research and Quality Registry of Patient Registries, and Google Scholar. The names and acronyms of registries and LOS were further searched in the Medline and Embase databases to retrieve published articles. Two independent reviewers undertook data collection, quality appraisal, and data extraction. Results We identified 88 registries/LOS that met our eligibility criteria. These were divided into 2 groups: disease-based (52 [59%]) and therapy-based (36 [41%]). Methodologic and reporting standards varied across the eligible studies. For clinical outcomes, disease activity was recorded in 88 (100%) of all LOS/registries. The most commonly reported measure (86 [98%]) was the composite outcome Disease Activity Score using 28 joints. Of the patient-centered outcomes collected, physical functioning was most frequently reported (75 [85%]) with the Health Assessment Questionnaire (75 [85%]) as the most commonly used instrument within this domain. Other domains of patient-centered outcomes were comparatively infrequently recorded: mental (29 [33%]), social (20 [23%]), and health-related quality of life (37 [42%]). Conclusion Most registries/LOS collect measures of disease activity and physical function. However, there is substantial heterogeneity in the collection of relevant patient-centered outcomes that measure symptom burden and mental and social ramifications of RA.