Early disease course and predictors of disability in juvenile rheumatoid arthritis and juvenile spondyloarthropathy: A 3 year prospective study

Objective. To describe the 3 year disease course in early juvenile rheumatoid arthritis (JRA) and juvenile spondy-loarthropathy (JSpA), to compare the health status after 3 years of followup with that of normal controls, and to investigate the relationship between physical function at followup and disease characteristics recorded during the first 6 months. Methods: One hundred and ninety-seven children (median age 6.6 yrs) with JRA and JSpA and disease duration < 1.5 years were examined by a pediatric rheumatologist every 6 months for a median of 3.1 years. Controls were randomly selected from the National Population Register. Physical and psychosocial health was assessed by means of the Child Health Questionnaire and the Childhood Health Assessment Questionnaire (CHAQ). Disease course was analyzed by analysis of variance for repeated measurements. Results. Health status and disease activity improved over time. Treatment with disease modifying antirheumatic drugs was started in 58% of the patients at baseline. Patients with persistent oligoarthritis had the most favorable disease course. The patients with juvenile ankylosing spondylitis (JAS), syndrome of seronegative enthesopathy and arthropathy (SEA), and rheumatoid factor (RF) positive polyarthritis had the poorest health status. A significant improvement for the whole group was observed after 3 years in all measures of disease activity and health status, except pain. Patients had poorer physical function and general health and more pain than controls. Predictors of reduced physical function at followup were a high CHAQ disability index and a poor well-being assessed during the first 6 months. Conclusion. Health status and disease activity improved over time in patients under medical treatment. The patients with JAS/SEA and RF positive polyarthritis had poorer health than the patients in other subtypes. A high disability index and a poor well-being at baseline predicted reduced physical function after 3 years.