Investigating which variables from the core outcome variables in juvenile idiopathic arthritis (JIA) are the best predictors of classification as a responder to treatment with methotrexate (MTX)

Methods Using a dataset of 410 JIA patients treated with MTX, (provided by PRINTO) 3 sets of logistic regression analyses were conducted, one at each classification level, to determine the likelihood of a classification of improvement. For each level a series of univariate logistic analyses were conducted to identify, from the six COV, individually significant (p < 0.05) predictors of improvement. These variables were entered into a stepwise multivariate logistic analysis to identify independent predictors of classification (p < 0.01) at each level.