Health-related quality of life in childhood arthritis: the impact of generic versus disease-specific instruments

Background Health-related quality of life (HRQoL) data provided by children with arthritis and their parents is critically important to enable co-design of care and shared decision making. However, there is significant heterogeneity in how HRQoL is captured, as both generic (EQ-5D-Y-5L) and disease-specific instruments (JAMAR) are available. This study aimed to examine the concordance of the JAMAR and EQ-5D-Y-5L questionnaires in childhood arthritis. Methods The international UCAN CAN-DU study prospectively enrolled consecutive children with arthritis across Canada and the Netherlands. This study included patients in whom corresponding JAMAR and EQ-5D-Y-5L questionnaires were completed on the same date by either the patients or their parents. The concordance of the questionnaire responses was measured by comparing the answers given to five specific JAMAR domains corresponding to the EQ-5D-Y-5L dimensions (anxiety/depression; mobility; pain/discomfort; self-care; usual activities). The impact of disease activity was assessed. Spearman’s correlation explored the association between global scales from the JAMAR and the EQ-5D-Y-5L. Results The study included 678 children with JIA; 63% were female; the median age at first questionnaire was 11.9 years (interquartile range: 6.2–15.1). Concordances between JAMAR and EQ-5D-Y-5L responses were found in 84% of the questions across all domains (84%, 82%, 85%, 87%, and 82% for anxiety/depression, mobility, pain/discomfort, self-care, and usual activities, respectively). In a state of inactive disease, generic and disease-specific instruments converged across all domains except for pain/discomfort. Comparison of global assessment scales revealed a high correlation between the EQ-5D-Y-5L and the JAMAR (Spearman’s correlation: R = -0.72, p < 0.001). Conclusions Patients and parents provided different responses to generic and disease-specific HRQoL instruments. The concordance was reduced in all domains except for pain/discomfort when children were experiencing high disease activity, highlighting the perceived conceptual differences and limitations of HRQoL instruments.