The natural history of juvenile chronic arthritis: a population based cohort study. II. Outcome

To investigate the outcome in a population based cohort of patients with juvenile chronic arthritis (JCA) who were in the process of being transferred from pediatric to adult rheumatology care.

The cohort of patients born in 1968 through 1972, recruited from a population based epidemiological study in southwestern Sweden, were called to a followup after a median disease duration of 7.1 years. The study group consisted of 124 patients with a median age of 17.7 years. The disability and discomfort dimensions were evaluated using the Childhood Health Assessment Questionnaire (C-HAQ). The impact of the disease on social life was evaluated by patients and parents.

The median C-HAQ disability index was 0.19 with a range from 0 to 2.75 (maximum possible score = 3). Sixty percent of the patients indicated some difficulty in daily activities. Female sex and a polyarticular disease course were risk factors for disability. The strongest determinants for disability were continuing disease activity and a positive IgM rheumatoid factor. Social impact of the disease was strongly linked to a raised C-HAQ disability index.

Even in a population based study of JCA, which includes many mild cases, the majority of patients experienced some difficulty in daily activities when judged by themselves. This underlines the necessity to use the patient's own values in outcome studies, rather than the physician's. Further development of internationally accepted, standardized instruments to evaluate the handicap dimension of childhood arthritis is called for.