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.

Cost-utility and budget impact analysis of tocilizumab for the treatment of refractory systemic juvenile idiopathic arthritis in Thailand.

OBJECTIVES: This study aimed to analyse the cost-utility and budget impact of adding tocilizumab to the standard treatment for patients with refractory systemic juvenile idiopathic arthritis (sJIA) in Thailand. DESIGN: Economic evaluation using a decision-analytical model. SETTING: Thailand. PARTICIPANTS: Patients with refractory sJIA who were ≥2 years old. METHODS: The use of tocilizumab as an add-on therapy to standard treatment was compared with standard treatment alone. A simulated health state transition model was used to estimate the lifetime costs and health outcomes from a societal perspective. Direct medical costs were collected from tertiary hospital databases while direct non-medical costs were derived from interviews. Health-related quality of life (QoL) was measured using the proxy version of three-level EuroQol five-dimensional questionnaire (EQ-5D-3L). Future costs and outcomes were discounted at an annual rate of 3%. The base case population was patients aged 9.41 years old at refractory disease onset. The results were reported as incremental cost-effectiveness ratios (ICER) in US dollar (USD). One-way and probabilistic sensitivity analysis were conducted to investigate parameter uncertainty. The 5-year budget impact was estimated from a governmental perspective. RESULTS: The ICER of standard treatment plus tocilizumab was US$35 799 per quality-adjusted life-year (QALY) gained compared with standard treatment alone, which was not cost-effective at the threshold of US$5128 per QALY gained. The estimated 5 years budget impact was approximately US$4.8 million. CONCLUSIONS: The use of standard treatment plus tocilizumab was not cost-effective in the Thai context, which has limited data. However, there is currently no second-line treatment for refractory sJIA in the Thai National List of Essential Medicines; thus, patients must receive higher doses of standard treatment which can cause many side effects. In contrast, tocilizumab showed obvious efficacy in clinical trials in improving treatment response and QoL. Therefore, the price of tocilizumab should be negotiated to reduce the financial impact on the healthcare system.

Juvenile idiopathic arthritis in Southeast Asia: the Singapore experience over two decades.

OBJECTIVES: To examine the clinical characteristics, treatment and outcomes of juvenile idiopathic arthritis (JIA) patients evaluated in Singapore and compare those with reports elsewhere. METHODS: Patients with JIA were recruited from our Singapore pediatric rheumatology registry from January 1997 to December 2015. Demographic, clinical, treatment, and outcome data were retrospectively collected. Nonparametric statistics were used to describe the data. Chi-squared, Mann-Whitney U, or Kruskal-Wallis tests were applied to compare differences between groups where appropriate. Multivariate logistic regression analyses were used to identify predictors for clinical parameters. RESULTS: Two hundred eighty-seven JIA patients with 60.6% males of predominantly Chinese descent were included in the study. The median onset age was 9 years (IQR 5.3-12.6), and the median follow-up duration was 30.1 months (IQR 9.1-61.7). Enthesitis-related arthritis (ERA, 32.8%) followed by persistent oligoarthritis (31.0%) was the most common. Elbow or ankle involvement predicted oligoarthritis extension (OR 15.8 (95% CI: 2.3-108.3, p = 0.005), 8.1 (95% CI: 1.5-45.3, p = 0.017)). JIA-associated uveitis was rare (2.8%) which paralleled the less common positive-ANA rate. Majority of our ERA patients had HLA-B27 (79.8%), together with older age predicted sacroiliitis (OR 4.7 (95% CI: 2.0-11.1, p < 0.05), OR 1.2 (95% CI: 1.1-1.3, p = 0.002)). TMJ involvement was under-reported. Methotrexate remained the most common DMARD used, but 36% of patients required biologics for which ERA and polyarthritis were the majority. Joint damage was rare. CONCLUSION: This study highlights geographical and ethnic differences in JIA epidemiology. Compared with reports elsewhere, our JIA population had many unique findings and good functional outcomes requiring regional study validation. Key points • ERA is the most prominent JIA subtype in Singapore with high prevalence of HLA-B27. • JIA-associated uveitis is rare in SEA and is not associated with ANA or JIA-subtypes. • Elbow and/or ankle involvement at presentation is associated with oligoarthritis extension in our JIA cohort.