Effects of adherence to treatment on short-term outcomes in children with juvenile idiopathic arthritis

Objective. To determine the impact of adherence to treatment (medication and prescribed exercise) on outcomes in children with juvenile idiopathic arthritis (JIA). Methods. In this longitudinal study, we studied parents of patients with JIA at the Montreal Children's Hospital and British Columbia Children's Hospital in Vancouver. Adherence was evaluated on a visual analog scale in the Parent Adherence Report Questionnaire. Outcomes of interest were active joint count, pain, child functional score on the Child Health Assessment Questionnaire, quality of life score on the juvenile Arthritis Quality of Life Questionnaire, and parental global impression of overall well-being. The association between adherence to treatment and subsequent outcomes was evaluated using generalized estimating equations and logistic regression. Results. Mean age and disease duration of our sample of 175 children were 10.2 and 4.1 years, respectively. Moderate adherence to medication was associated with lower active joint count (odds ratio [OR] 0.47, 95% confidence interval [95% CI] 0.22-0.99). Moderate adherence to exercise was associated with better functional score (OR 0.13, 95% Cl 0.03-0.54), and lower pain during the last week (OR 0.14, 95% CI 0.04-0.50). Both high and moderate adherence to exercise were associated with parental perception of global improvement. Conclusion. Improved outcomes in patients who adhered to treatment underscores the need for clinicians to address adherence issues with their patients. Sustaining adherence, particularly to the more time-consuming treatment of exercise, is a challenge.