Psychometric properties of the Mandarin Chinese self-reported Pediatric Quality of Life Inventory™ Version 4.0 Generic Core Scales in school adolescents: based on the Rasch and bifactor measurement methods

The Pediatric Quality of Life Inventory™ Version 4.0 Generic Core Scales (PedsQL™ 4.0 GCS) is widely used to assess health-related quality of life (HRQoL) in healthy children and adolescents, as well as those with acute and chronic health conditions. This study evaluates the psychometric properties of the Mandarin Chinese self-reported PedsQL™ 4.0 GCS. A comprehensive psychometric evaluation was conducted using Rasch and bifactor measurement methods. Data were drawn from a cross-sectional survey conducted in Weifang City, the Chinese Mainland, from October to November 2016, involving 4385 healthy school adolescents aged 11–17 years. Rasch analysis indicated acceptable item response validity, item and person reliability, and cross-gender measurement invariance in healthy school adolescents. However, mistargeting and cross-grade measurement non-invariance require further attention. Bifactor analysis further supported the construct validity and essential unidimensionality of both summary scores, especially the Psychosocial Health score. Additionally, bifactor model-based reliability confirmed the robustness of the scale when divided into Physical and Psychosocial Health subscales. The Mandarin Chinese self-reported PedsQL™ 4.0 GCS demonstrates generally sound psychometric properties in healthy school adolescents, though some psychometric issues remain. Further validation in other regions of the Chinese Mainland or in clinical samples is recommended.