A 5-year prospective population-based study of juvenile chronic arthritis: onset, disease process, and outcome

Abstract

Objectives: To investigate, in a population-based cohort of patients with juvenile chronic arthritis (JCA), onset characteristics, progression, outcome, and prognostic factors longitudinally for 5 years.

Methods: This cohort consisted of 132 incidence cases identified between 1984 and 1986 in southwestern Sweden followed for 5 years with annual reports of subgroup, joint assessment, disease activity, eye examinations, laboratory measurements, and medication. At the 5-year follow-up, the Childhood Health Assessment Questionnaire (Child-HAQ) was evaluated. European League Against Rheumatism (EULAR) criteria for diagnosis and disease activity were used.

Results: During the 5 years only four patients were lost to follow-up, 34% changed subgroup and 8% developed uveitis. At the 5-year follow-up the disease was active in 12% of the patients, stable in 28%, inactive in 25%, and in remission in 34%. Among those examined, 24% had radiological changes, of whom half had advanced changes. The Child-HAQ median score at the 5-year follow-up was 0.13 (range 0.0–1.9). The number of involved joints at inclusion correlated positively with active disease at the 5-year follow-up. Age at disease onset, the number of involved joints, and the number of joints with arthritis correlated positively with continuous disease and Child-HAQ score.

Conclusion. Our study shows a diverse disease course during the first 5 years of JCA where one-third changed subgroup and two-thirds did not reach remission. Age of disease onset, the number of involved joints, and the number of joints with arthritis at inclusion were associated with poor outcome at the 5-year follow-up.

Acknowledgements

This study was supported by grants from the Health and Medical Care Executive Board of the Region Västra Götaland, Rune and Ulla Amlövs Foundation for Rheumatology Research, the Swedish National Association Against Rheumatism, the Medical Society of Göteborg, and the Region Västra Götaland (agreement concerning research and education of doctors). We are very grateful to all the patients and their parents for participating in this study and to all the paediatricians for completing the annual reports.