Validity and Reliability of Four Parent/Patient–Reported Outcome Measures for Juvenile Idiopathic Arthritis Remote Monitoring

The aim of this work was to provide evidence of validity and reliability for 4 parent/child–reported outcome measures included in the Outcome Measures in Rheumatology juvenile idiopathic arthritis core domain set: the evaluation of the child's pain and level of disease activity, the assessment of morning stiffness duration, and an active joint count for proxy/self‐assessment. Patients were included in the multinational study Epidemiology Treatment and Outcome of Childhood Arthritis. Criterion validity was assessed by examining the correlation of the 4 tested measures with physician measures and the clinical Juvenile Arthritis Disease Activity Score in 10 joints (cJADAS10) in the whole sample and after grouping patients by International League of Associations for Rheumatology (ILAR) category, geographic area, and education level. Reliability was assessed comparing 2 visits 7–14 days apart with intraclass correlation coefficients (ICCs). A total of 8,643 parents and 6,060 patients had all the evaluations available. Correlations of tested measures were moderate (0.4–0.7) with physician‐reported measures. The level of correlation with the cJADAS10 remained stable after grouping patients by ILAR category, geographic areas, and level of education of the parent filling the questionnaire. In 442 parents and 344 children, ICCs ranged between 0.79 and 0.87 for parents and 0.81 and 0.88 for children. The 4 tested parent/child–reported outcomes showed good criterion validity and excellent reliability. These tools can be considered for remote patient assessment, when in‐person evaluation might not be possible.