Objective 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. Methods 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). Results 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. Conclusion 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.