Outcomes and predictors of juvenile idiopathic arthritis in Southeast Asia: a Singapore longitudinal study over a decade

Objective: To assess short- and long-term outcomes and predictors of juvenile idiopathic arthritis (JIA) children treated with contemporary therapy and compare those with reports elsewhere.

Methods: Children with JIA were recruited from our web-based REgistry for Childhood Onset Rheumatic Diseases (RECORD) from 1997 to 2015. Disease status was defined using modified Wallace criteria. Nonparametric statistics described the data. Kaplan-Meier survival and logistic regression analyses were used to estimate probabilities and to determine predictors of outcomes.

Results: A total of 251 children with JIA (62% males, 71% Chinese) were included. Median follow-up duration was 2.9 years (range 0.1-17.5). Short-term clinical inactive disease (CID) was attained in 37% with 62% systemic JIA (sJIA) and 47% persistent oligoarthritis (oJIA). Methotrexate (OR 0.34) decreased but sJIA (OR 3.25) increased chance of attaining CID at 6 months. Overall, 79% of patients achieved CID within 2 years (sJIA 92%, the highest, and RF+ polyarthritis 50%, the lowest probability). Biologics were associated with CID attainment (OR 2.73). One-half of patients flare after CID, median 1.2 years (IQR 0.71-1.97). Late CID achievement predicted flare (OR 2.15). Only 15% had clinical remission off medication (none RF+ polyarthritis and 7% ERA). Only 13% of patients had active arthritis as young adults and 22% had active arthritis at last visit.

Conclusion: Despite high proportion of JIA patients attaining CID, only one-fourth could stop all medications for at least 1 year. Persistent oJIA patients were less likely to achieve clinical remission on medication and ERA patients had the least chance stopping medications. One-tenth of patients had active arthritis as young adults. Key Points • Majority of Asian children with JIA attained inactive disease within 2 years after diagnosis. • Outcome predictors were different from reports from the West. • Despite high inactive disease numbers, only one-in-four JIA patients discontinued treatment within 5 years.