Real‐World Effectiveness of Common Treatment Strategies for Juvenile Idiopathic Arthritis: Results From a Canadian Cohort

OBJECTIVE: Undervaluing the effectiveness of conventional treatments may lead to overtreatment with biologic medications in children with juvenile idiopathic arthritis (JIA). Using data from a nationwide inception cohort and strict methods to control bias, the aim of our study was to estimate the real-world effectiveness of simple JIA treatment strategies recommended in current guidelines. METHODS: Children with JIA who were recruited at 16 Canadian centers from 2005 to 2010 were followed for up to 5 years. For each child, all observed treatment changes over time were assessed by independent physicians using prospectively collected data and published response criteria. Success was defined as attainment of inactive disease or maintenance of this state when stepping down treatment; minimally active disease was deemed acceptable for children with polyarticular JIA. Success rates were calculated for treatments tried ≥25 times, and logistic regression analysis identified features associated with success. RESULTS: A total of 4,429 treatment episodes were observed in 1,352 children. Nonsteroidal antiinflammatory drug (NSAID) monotherapy was attempted 697 times, mostly as initial treatment when <5 joints were involved, with a 54.4% success rate (95% confidence interval [95% CI] 50.3-58.6). NSAIDs plus joint injections had a 64.7% success rate (95% CI 59.8-69.7). Adding methotrexate to NSAIDs and/or joint injections (attempted 566 times) had a 60.5% success rate (95% CI 55.7-65.3). In adjusted analyses, each additional active joint reduced chances of success for treatment with NSAIDs (odds ratio [OR] 0.90 [95% CI 0.85-0.94]) and for methotrexate combinations (OR 0.96 [95% CI 0.94-0.99]). Each additional year after disease onset reduced chances of success for treatment with methotrexate combinations (OR 0.83 [95% CI 0.72-0.95]). CONCLUSION: These real-world effectiveness estimates show that conventional nonbiologic treatment strategies that are recommended in current guidelines are effective in achieving treatment targets in many children with JIA.