To compare the clinical effectiveness of different strategies (CTPs) for using biologic medications in achieving clinically inactive disease (CID) at 12 months in new-onset pJIA. Three common strategies that differ in the timing of biologic medication introduction will be compared: 1) Step-Up: disease modifying anti-rheumatic drug (DMARD) monotherapy stepping up by addition of a biologic medication if needed; 2) Early Combination: DMARD plus biologic medication at treatment onset; and 3) Biologic First: biologic medication monotherapy at treatment onset.