Objectives: To evaluate current (inter)national registers and observational cohorts in Europe, and to compare inclusion criteria, aims, collected data, and participation in the European League Against Rheumatism (EULAR) repository.
Method: We performed a systematic search strategy in six literature databases for rheumatoid arthritis (RA). Publications reporting European (inter)national prospective registers/cohorts including > 200 RA patients with at least half a year of follow-up were selected.
Results: In total, 417 articles and abstracts were included from four international databases and 39 national databases/cohorts. International databases were of similar design, frequency of data collection and selection criteria and are mostly initiated to monitor and compare clinical patient care among countries. National databases/cohorts vary in aims and inclusion criteria. Half of the national registers are connected to the EULAR repository of databases.
Conclusions: Our findings indicate that, among researchers, there is little awareness of guidelines to set up registers or cohorts and of the existence of the database collaboration network of EULAR.