Longitudinal analysis of a pediatric rheumatology clinic population.

OBJECTIVE: To analyze a prospectively maintained pediatric rheumatology clinic disease registry.
METHODS: A total of 3269 consecutive referrals to the Pediatric Rheumatology Clinic, University of Saskatchewan, during the period 1981-2004 were analyzed.
RESULTS: Among 3269 patients, a diagnosis was established in 2098 (64.2%). Within this group, 72 subjects (3.4%) were determined to be healthy. Of the remaining 2026 diagnosed patients (62.0% of the total population), 1032 (50.9%) had a rheumatic disease and 994 (49.1%) a nonrheumatic disease. A diagnosis was not established in 1171 patients (35.8%). Among the 1032 patients with a rheumatic disease, 326 (31.6%) had juvenile rheumatoid arthritis (JRA), 360 (34.9%) a spondyloarthropathy (SpA), and 225 (21.8%) a collagen vascular/connective tissue rheumatic disease. The remaining 121 patients with a rheumatic disease (11.7%) had a variety of other conditions. Of the 994 nonrheumatic disease patients, 37 (3.7%) with ocular inflammatory conditions had been referred to exclude an associated rheumatic disease. The remaining group of 957 patients comprised 345 (36.1%) with an orthopedic, mechanical or traumatic condition, 231 (24.1%) had an infection, 45 (4.7%) a hematologic or neoplastic disease, and 336 (35.1%) a variety of other conditions. Current clinic point prevalences for JRA, SpA, and collagen vascular diseases are 35.0, 16.9 and 17.7/100,000, respectively. The mean annual clinic referral incidences of JRA, SpA, and collagen vascular/connective tissue diseases were, respectively, 4.7, 5.2, and 1.7/100,000 children.
CONCLUSION: Disease registries help establish the frequencies and spectrum of childhood rheumatic diseases and the role of pediatric rheumatology programs in evaluating and caring for children with a wide variety of conditions. Longitudinal disease registries aid in characterizing clinical, epidemiologic, and demographic features of childhood rheumatic diseases.