Psychometric Evaluation of the Proxy-Reported Pediatric Quality of Life Inventory Generic Core Scales Across the Childhood Lifespan in Australian Children and Adolescents With Specified Health Conditions

<h4>Objectives</h4>Current generic childhood health-related quality-of-life instruments lack comprehensive psychometric evidence across all ages. The Pediatric Quality-of-Life Inventory v4.0 Generic Core Scales (PedsQL GCS) covers ages 2 to 18 years old, but evidence on its psychometric properties is limited to restricted age groups. This study aimed to evaluate the proxy-reported PedsQL GCS across the entire childhood lifespan.<h4>Methods</h4>The study used data from the Longitudinal Study of Australian Children for children aged 2 to 17 years with 1 of 6 health conditions: high weight status, eczema, attention deficit hyperactivity disorder, vision problems, hearing problems, and learning difficulty. Psychometric properties of the proxy-reported PedsQL GCS were assessed in early childhood, middle childhood, and adolescence against established criteria.<h4>Results</h4>In analyses of 9317 children with 50 934 total observations, the PedsQL GCS demonstrated good acceptability across the childhood lifespan, except for high rates of missing data in 2 to 9 year olds (range = 12%-30%). Strong internal consistency was evident across health conditions and age (α range = 0.72-0.93; item-total correlations range = 0.28-0.80). Known group validity was strong with differentiation between children with/without the condition across all ages, except for eczema. Responsiveness was variable with inconsistencies mainly in early childhood.<h4>Conclusions</h4>This study adds to the PedsQL psychometric evidence base, finding that the proxy-reported PedsQL GCS demonstrated robust reliability and known group validity, good acceptability, and mixed responsiveness in Australian children with health conditions across age. We propose the PedsQL GCS as a robust instrument to take forward for valuation to directly generate utility values for use in economic evaluations.