Recommendations for the treatment of juvenile idiopathic arthritis with oligoarthritis or polyarthritis from the 2024 update of the Japan College of Rheumatology Clinical Practice Guidelines for the management of rheumatoid arthritis including juvenile idiopathic arthritis with oligoarthritis or polyarthritis – secondary publication

OBJECTIVES: To conduct systematic reviews (SRs) and develop clinical practice guidelines (CPGs) for managing juvenile idiopathic arthritis (JIA) with oligoarthritis or polyarthritis. METHODS: The Grading of Recommendations, Assessment, Development, and Evaluation methodology was employed to carry out SRs and formulate the CPGs. An expert panel, including patients, paediatric and nonpaediatric rheumatologists, guideline specialists, and patient representatives, used the Delphi method to discuss and agree on the recommendations. RESULTS: Six clinical questions (CQs) on the efficacy and safety of medical treatments were evaluated. These included CQ1 on methotrexate (MTX), CQ2 on non-MTX conventional synthetic disease-modifying antirheumatic drugs, CQ3 on glucocorticoids, CQ4 on tumour necrosis factor inhibitors, CQ5 on interleukin-6 inhibitors, and CQ6 on Janus kinase inhibitors. Two randomized controlled trials were identified for CQ1, three for CQ2, two for CQ3, eight for CQ4, two for CQ5, and two for CQ6. Based on these evaluations, three strong and three conditional recommendations were established. The CPGs have been endorsed by the Japan College of Rheumatology and the Pediatric Rheumatology Association of Japan. CONCLUSIONS: The SRs provided the necessary evidence to develop the CPGs, which are intended to guide not only paediatric but also nonpaediatric rheumatologists, caregivers, patients, and their families in treatment decision-making.