RÉSUMÉ
OBJECTIVE: The objective of this study was to examine the psychometric properties of the EQ-5D-Y-3 L, Patient Reported Outcomes Measurement System 25-item version profile v2.0 (PROMIS-25), and Pediatric Quality of Life Inventory™ version 4.0 Generic Core Scale (PedsQL 4.0) in Chinese pediatric patients with spinal muscular atrophy (SMA). METHODS: The data used in this study were obtained via a web-based cross-sectional survey. Parents of pediatric patients with SMA completed the proxy-reported EQ-5D-Y-3 L, PedsQL 4.0, and PROMIS-25 measures. Information about socioeconomic and health status was also obtained. The ceiling and floor effects, factorial structure, convergent validity, and known-group validity of the three measures were assessed. RESULTS: Three hundred and sixty-three parents of children aged from 5 to 12 completed the questionnaires. Strong floor effects were observed for the physical function components of the PROMIS-25 (41.3%) and PedsQL 4.0 (67.8%). For EQ-5D-Y-3 L, 84.6% of the respondents reported having "a lot of" problems with the dimensions "walking" and "looking after myself." Minimal ceiling or floor effects were observed for the EQ-5D-Y-3 L index value. The confirmatory factor analysis supported a six-factor structure for the PROMIS-25, but did not support a four-factor structure for the PedsQL 4.0. All hypothesized correlations of the dimensions among the three measures were confirmed, with coefficients ranging from 0.28 to 0.68. Analysis of variance showed that EQ-5D-Y-3 L demonstrated better known-group validity than the other two measures in 14 out of 16 comparisons. CONCLUSIONS: The EQ-5D-Y-3 L showed better discriminant power than the other two measures. The physical health dimensions of all three measures showed the significant floor effects. These findings provide valuable insights into the effectiveness of these measures at capturing and quantifying the impact of SMA on patients' health-related quality of life.