The clinical features of elderly-onset rheumatoid arthritis. A comparison with younger-onset disease of similar duration.

Patients with elderly-onset rheumatoid arthritis (EORA) may represent a clinical subset of individuals who differ prognostically and therapeutically from patients with younger-onset disease (YORA). In order to test this hypothesis, we reviewed the records of 212 patients with rheumatoid arthritis and grouped them according to age at onset above or below 60 years old. Seventy-eight EORA patients and 134 YORA patients with disease duration of less than or equal to 10 years were used for a comparison of presenting features and disease outcome. Abrupt onset occurred somewhat more frequently in EORA, but was not associated with a significantly different clinical course than was an insidious presentation in this older group. There were no differences between the EORA and YORA groups in terms of mean initial joint score, although the scores for the YORA group had wider variation. An initial clinical presentation resembling polymyalgia rheumatica (PMR) was 4 times as frequent in EORA. Elderly patients were less likely to have subcutaneous nodules or rheumatoid factor at disease onset. At the final examination, the EORA patients had lower joint scores and higher health assessments despite similar courses of treatment. These outcome differences persisted when patients with PMR-like presentations were excluded. Multivariate analyses indicated that joint scores and disease duration made important contributions to a better outcome of EORA, whereas PMR presentation and abrupt onset did not. After an adjustment was made for these 4 features, age at onset was an important contribution to joint score outcome. These results confirm the existence of important differences in onset, clinical features, and prognosis between patients with EORA and those with YORA.