Rheumatoid arthritis in Spain: occurrence of extra-articular manifestations and estimates of disease severity

To characterise RA in a sample of Spanish patients by estimating mean clinical activity, functional ability, and radiological damage, and current and cumulative prevalence of extra-articular manifestations.

Cross sectional analysis of a cohort of patients with RA randomly selected from the clinical databases of 34 centres. Standard definitions and measurements were used, and radiographs read centrally. Estimates and confidence intervals were adjusted to sampling.

Data were available for 788 patients. Extra-articular RA was present in 285 (36.2%) patients. Cumulative prevalence and 95% confidence intervals of extra-articular manifestations were estimated: nodules 24.5% (21.5 to 27.5), Sjögren's syndrome 17.0% (14.4 to 19.6), atlantoaxial subluxation 12.1% (9.8 to 14.4), carpal tunnel syndrome 10.7% (7.8 to 13.6), interstitial lung disease 3.7% (2.4 to 5.0), serositis 2.5% (1.4 to 3.5), eye disease 2.5% (1.1 to 3.9), vasculitis 1.3% (0.5 to 2.1), amyloidosis 0.6% (0.1 to 1.2), and Felty's syndrome 0.3% (<0.6). Mean (SD) activity/progression indexes were: DAS28-3 3.4 (1.2), HAQ 1.6 (0.4), Larsen score 54.7 (26.4). Less than 5% of the patients were in remission. 205 (72%) patients were receiving disease modifying antirheumatic drugs (DMARDs).

Spanish patients with RA ever seen by a rheumatologist have, on average, a moderate degree of activity, despite widespread use of DMARDs. Measures of the degree of progression do not show a benign disease. The proportion of extra-articular manifestations in Spanish patients with RA is similar to that found in other Mediterranean populations, and lower than that reported in Anglo Saxon countries.