Abstract
Juvenile idiopathic arthritis (JIA) is a common chronic illness in childhood and comprises seven categories based on the International League of Associations for Rheumatology (ILAR) criteria. Accurate assessment and measurement of the clinical, functional, and quality of life outcomes of patients with JIA are paramount for understanding the disease course and formulating effective treatment strategies. Interest in the development and use of outcome measurements specifically focused on rheumatologic conditions has greatly expanded over the last two decades, adding to and improving upon the established disease measures. Furthermore, many of these measures have been validated using the widely accepted Outcome Measures in Rheumatology (OMERACT) core principles of instrument validation, allowing researchers and clinicians to gain confidence in these tools. This review summarizes the current validated disease outcome measures in JIA, including clinical, imaging, patient-reported, and functional outcome measurement tools, and highlights ongoing work that continues to refine and improve upon the available tools. The clinical disease outcome measures discussed in this review include physician global assessment (PhGA), American College of Rheumatology (ACR, Wallace) criteria for clinical inactive disease and clinical remission, juvenile arthritis disease activity scores (JADAS), juvenile spondyloarthritis disease activity index (JSPaDA), juvenile arthritis damage index (JADAI), and the ACR pediatric response scores. The imaging outcome measures discussed include the Dijkstra composite scores, childhood arthritis radiographic score of the hip (CARSH), and Poznanski Score. The patient-reported disease outcome measures discussed include patient global assessment (PtGA), patient-reported outcome measurement information system for JIA (PROMIS), juvenile arthritis parent/child centered disease assessment index (JAPAI, JACAI), juvenile arthritis multidimensional assessment report (JAMAR), and the Pediatric quality of life inventory rheumatology module (PedsQL). The functional outcome tools discussed include the Childhood Health Assessment Questionnaire (CHAQ), juvenile arthritis functionality scale and index (JAFS and JASI), and Juvenile Arthritis Functional Assessment Report and Scale (JAFAS and JAFAR).