The influence of age at disease onset on disease activity and disability: results from the Ontario Best Practices Research Initiative

This study aims to compare characteristics between late-onset rheumatoid arthritis (RA) and young-onset RA and determine the association between age at disease onset and disease severity. We cross-sectionally studied 971 patients at the time of entry into the Ontario Best Practices Research Initiative, a registry of RA patients followed up in routine care. We restricted patients to ≤5 years of disease duration. Late-onset RA was defined as an onset ≥60 years of age and young-onset RA