Development of a scoring system to assist clinicians in the early referral of patients with suspected juvenile idiopathic arthritis: the EasyJIA score

ObjectiveJuvenile idiopathic arthritis (JIA) is the most common chronic pediatric rheumatic disease. Early referral to a specialized center is crucial for prompt diagnosis and treatment. This study aims to develop and validate a scoring system to assist clinicians in efficiently identifying and referring patients suspected of having non-systemic JIA.MethodsWe conducted a cohort study with a mixed design (retrospective and prospective), involving consecutive patients presenting with joint complaints who were referred for the first time to the Pediatric Rheumatology Unit at ASST G. Pini-CTO Hospital. The model was developed using multivariate logistic regression with bootstrap resampling and the Lasso (Least Absolute Shrinkage and Selection Operator) method for variable selection.ResultsA total of 342 patients were included, of whom 61 (18%) were diagnosed with JIA. The selected variables for the model were: type of joint (large), daily symptoms, joint swelling, activity as a precipitating factor, a positive squeeze test of the metatarsophalangeal/metacarpophalangeal (MTP/MCP) joints, normal bending of the interphalangeal (IF) joints of the hands, morning limping and/or stiffness, and sacroiliac tenderness. The ROC curve, based on the model's regression score, showed an AUC of 0.92 with an overall accuracy of 0.88 (95% CI: 0.84-0.91) using a cutoff of 3 points, yielding a sensitivity of 95% and a specificity of 71%. Initial internal validation of the model revealed an AUC of 0.92 (95% CI: 0.89-0.95).ConclusionThis study presents and initially validates a simple and efficient scoring system to aid clinicians in the early referral of patients suspected of having non-systemic JIA.Clinical trial numberNot applicable.