Objective: To examine the descriptive epidemiology of a regional cohort of children with rheumatic disease, and to document the variety and frequency of diseases encountered among pediatric rheumatology centers.
Methods: Pediatric rheumatology centers in southern New England participated in a prospective multicenter patient registry. All outpatients attending clinics at 8 pediatric rheumatology centers were enrolled as subjects during the 8-year period of study (n = 4585). Diagnostic criteria defined the rheumatic disease cases which were determined by clinical examination by a pediatric rheumatologist, and record linkage was achieved to avoid duplication of subjects.
Results: Rheumatic conditions were diagnosed in 1742 subjects. Juvenile rheumatoid arthritis (JRA) was the most frequently encountered rheumatic condition (53%), followed by spondyloarthropathy syndromes (13%), vasculitis (10%), systemic lupus erythematosus (SLE) (6%), isolated Raynaud's phenomenon (5%), dermatomyositis/polymyositis (DM/PM) (5%), and scleroderma (2%). The mean annual incidence of JRA, spondyloarthropathy syndromes, SLE and DM/PM among children referred to pediatric rheumatology centers in Massachusetts was 4.0, 2.0, 0.4 and 0.4 per 100,000 children at risk, respectively. Nonrheumatic conditions were diagnosed in 2843 subjects, among which musculoskeletal conditions were most frequent (56%) followed by infectious disorders (18%), psychogenic disorders (3%), fever of unknown origin (2%), and abnormal immune serology without a specific diagnosis (2%).
Conclusion: The use of a multicenter patient registry was successful in allowing the collection of descriptive epidemiologic data on a large and well defined sample of children with rare disorders.