Background: Achieving the best possible health-related quality of life (HRQoL) for a patient is an important treatment goal in juvenile idiopathic arthritis (JIA). We investigated the 36-month trajectories of HRQoL in children with JIA compared with healthy peers and identified the predictors of an unfavorable HRQoL.
Methods: Patients with a recent JIA diagnosis were enrolled in the German inception cohort study ICON. As a peer group, friends of patients of the same age and sex were asked to cooperate. Children were prospectively followed and regularly questioned about their HRQoL using the Pediatric Quality of Life Inventory 4.0 (PedsQL). Disease activity was assessed by the clinical Juvenile Arthritis Disease Activity Score (cJADAS-10), and the burden of the child's chronic illness on their family was assessed by the Family Burden Questionnaire (FaBel). Linear mixed models were used to compare the HRQoL of the patients and their peers. Associations between the health status of a patient at enrollment and an unfavorable HRQoL (PedsQL total < 79.3) at their 3-year follow-up (FU) were analyzed by logistic regression.
Results: Data from 953 patients (median symptom duration 6 months, mean age 7.9 years) and 491 healthy peers (aged 8.4 years) were analyzed. During 3 years of FU, the disease activity and HRQoL of the patients improved significantly (cJADAS-10 from 9.8 (6.2) to 2.7 (3.6) and PedsQL total score from 71.7 (18.2) to 87.3 (13.9)). While the HRQoL of the patients varied among the several JIA categories at the time of enrollment, no significant differences were found at the 3-year FU. After 36 months, the HRQoL of the patients had largely converged with that of their healthy peers. JIA patients had a psychosocial health status comparable with their healthy peers, whereas a small significant mean difference remained in physical health (5.8, 95% confidence interval (CI) 4.1-7.6). Up to the 36-month FU, three-quarters of JIA patients attained a favorable HRQoL (PedsQL ≥ 79.3) which was achieved by 90% of the peers. A higher family burden, higher pain level, and lower well-being at enrollment were associated with an unfavorable HRQoL.
Conclusions: Under current therapeutic conditions, an HRQoL corresponding with that of healthy children is a realistic treatment goal in JIA.
Keywords: Inception cohort; Juvenile idiopathic arthritis; Outcome; Quality of life.