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

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.

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.

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.