Responsiveness of the EQ-5D-Y-5L Parent-Proxy Version Among Children with Juvenile Idiopathic Arthritis

Valid and reliable health-related quality of life (HRQoL) instruments are needed in clinical practice to quantify the burden of juvenile idiopathic arthritis (JIA) and capture changes in health over time. We examined the responsiveness of the parent-proxy EuroQol 5-Dimension Youth 5-Level (EQ-5D-Y-5L) instrument in children with JIA.

This multicenter international cohort study included consecutive children with JIA who were enrolled in the Understanding Childhood Arthritis Network Canadian-Dutch (UCAN CAN-DU) eHealth platform. Demographics, Clinical Juvenile Arthritis Disease Activity Score-10 (cJADAS10) disease activity, Childhood Health Assessment Questionnaire (CHAQ) disability index, and health status were assessed at baseline and at follow-up visits 3-12 months later. Patients were categorized as improved, stable, or deteriorated using cJADAS10 and CHAQ. Responsiveness was evaluated at both the dimension level (distributional change) and continuous score level (EQ-5D-Y-5L level summary score [LSS] and EuroQol Visual Analogue Scale [EQ VAS]) using effect size and standardized response mean (SRM).

A total of 246 patients were included (median age 12 years [interquartile range: 8-15]; 54% female). At the dimension level, children classified as improved showed clear shifts toward lower problem levels across all five EQ-5D-Y-5L dimensions, particularly in physical dimensions, while stable patients showed minimal distributional change. At the continuous score level, improvements were mostly associated with large effect size and SRM for both LSS and EQ VAS (0.8-1.6), whereas changes in stable groups were negligible to small.

The parent-proxy EQ-5D-Y-5L demonstrates responsiveness to clinically defined changes in children with JIA. Its ability to detect improvement while remaining stable in the absence of change supports its use in longitudinal clinical studies and economic evaluations.