Trajectories of disease activity in patients with JIA in the Childhood Arthritis and Rheumatology Research Alliance Registry

OBJECTIVE: To describe 2-year trajectories of the clinical Juvenile Arthritis Disease Activity Score, 10 joints (cJADAS10) and associated baseline characteristics in patients with juvenile idiopathic arthritis (JIA).

METHODS: JIA patients in the Childhood Arthritis and Rheumatology Research Alliance Registry enrolled within 3 months of diagnosis from June 15, 2015 to December 6, 2017 with at least 2 cJADAS10 scores and 24 months of follow-up were included. Latent growth curve models of cJADAS10 were analyzed; a combination of Bayesian information criterion, posterior probabilities, and clinical judgement were used to select model of best fit.

RESULTS: Five trajectories were identified among the 746 included patients: High, Rapidly Decreasing (HRD) (n = 199, 26.7%); High, Slowly Decreasing (HSD) (n = 154, 20.6%); High, Increasing (HI) (n = 39, 5.2%); Moderate, Persistent (MP) (n = 218, 29.2%); and Moderate, Decreasing (MD) (n = 136, 18.2%). Most patients spent a significant portion of time at moderate to high disease activity levels. At baseline, HSD patients were more likely to be older, have a lower physician global assessment, normal inflammatory markers, longer time to first biologic, and have taken systemic steroids compared with HRD. Those with a HI trajectory were more likely to be ANA negative, have a longer time to first biologic, and less likely to be taking a csDMARD compared with HRD. MP patients were more likely to be older with lower household income, longer time to diagnosis, and markers of higher disease activity than those with a MD trajectory.

CONCLUSIONS: Five trajectories of JIA disease activity, and associated baseline variables were identified.