Critical Outcomes in Longitudinal Observational Studies and Registries in Patients with Rheumatoid Arthritis: An OMERACT Special Interest Group Report

Objective. Outcomes important to patients are those that are relevant to their well-being, including quality of life, morbid endpoints, and death. These outcomes often occur over the longterm and can be identified in prospective longitudinal observational studies (PLOS). There are no standards for which outcome domains should be considered. Our overarching goal is to identify critical longterm outcome domains for patients with rheumatic diseases, and to develop a conceptual framework to measure and classify them within the scope of OMERACT Filter 2.0. Methods. The steps of this initiative primarily concern rheumatoid arthritis (RA) and include (1) performing a systematic review of RA patient registries and cohorts to identify previously collected and reported outcome domains and measurement instruments; (2) developing a conceptual framework and taxonomy for identification and classification of outcome domains; (3) conducting focus groups to identify domains considered critical by patients with RA; and (4) surveying patients, providers, and researchers to identify critical outcomes that can be evaluated through the OMERACT filter. Results. In our initial evaluation of databases and registries across countries, we found both commonalities and differences, with no clear standardization. At the initial group meeting, participants agreed that additional work is needed to identify which critical outcomes should be collected in PLOS, and suggested several: death, independence, and participation, among others. An operational strategy for the next 2 years was proposed. Conclusion. Participants endorsed the need for an initiative to identify and evaluate critical outcome domains and measurement instruments for data collection in PLOS.