The Childhood Arthritis Prospective Study (CAPS) is a longitudinal study of children with a new JIA diagnosis. CAPS data includes demographics and core outcome variables at baseline, 6 months and yearly thereafter. Prevalence and transition rates from baseline to 5 years were obtained for active and limited joint counts at the hip, knee, ankle, and foot joints; and walking disability, measured using the Childhood Health Assessment Questionnaire walking subscale. Missing data were accounted for using multiple imputation.
A total of 1,041 children (64% female), with a median age of 7.7 years at first visit were included. Baseline knee and ankle synovitis prevalence was 71% and 34% respectively, decreasing to between 8-20% and 6-12% respectively after 1 year. Baseline hip and foot synovitis prevalence was less than 11%, decreasing to less than 5% after 6 months. At least mild walking disability was present in 52% at baseline, stabilising at 25-30% after 1 year.
Lower limb synovitis and walking disability are relatively common around the time of initial presentation in children and young people with JIA. Mild to moderate walking disability persisted in approximately 25% of patients for the duration of the study, despite a significant reduction in frequency of lower limb synovitis. This suggests that there is an unmet need for non-medical strategies designed to prevent and/or resolve persistent walking disability in JIA.
- juvenile idiopathic arthritis
- lower limb
- walking disability