Extra-articular rheumatoid arthritis: prevalence and mortality.

Abstract

The prevalence and distribution of extra-articular manifestations of rheumatoid arthritis (ExRA) and associated mortality were studied retrospectively in a cohort of RA patients admitted to University Hospital, Malmö, Sweden, during the period 1990-94. Of 489 patients who fulfilled the 1987 ACR criteria for RA, 37 manifested onset of ExRA, predominantly serositis and cutaneous vasculitis, during the period, corresponding to a cumulative incidence of 7.9%. The occurrence of ExRA was independent of disease stage. Among patients with ExRA, 1 death/4.3 person-years at risk (pyr) occurred, as compared with 1 death/11.4 pyr in the non-ExRA subgroup. The age- and sex-adjusted mortality rate ratio was 2.49 (95% confidence interval 1.43-4.03). The major cause of death among ExRA cases was heart disease, which occurred in 9/13 cases (69%) in comparison to the expected 2.4 cases. In this series, serositis and cutaneous vasculitis were predominant extra-articular manifestations of RA; and mortality was greater in the ExRA than in the non-ExRA subgroup, perhaps due to a high frequency of associated heart disease.