Longitudinal factorial invariance of the PedsQL™ 4.0 Generic Core Scales Child Self-Report Version: One year prospective evidence from the California State Children’s Health Insurance Program (SCHIP)

Background  The measurement of health-related quality of life (HRQOL) in pediatric medicine and health services research has grown significantly over the past decade. The paradigm shift toward patient-reported outcomes (PROs) has provided the opportunity to emphasize the value and critical need for pediatric patient self-report. In order for changes in HRQOL/PRO outcomes to be meaningful over time, it is essential to demonstrate longitudinal factorial invariance. This study examined the longitudinal factor structure of the PedsQL™ 4.0 Generic Core Scales over a one-year period for child self-report ages 5–17 in 2,887 children from a statewide evaluation of the California State Children’s Health Insurance Program (SCHIP) utilizing a structural equation modeling framework. Methods  Specifying four- and five-factor measurement models, longitudinal structural equation modeling was used to compare factor structures over a one-year interval on the PedsQL™ 4.0 Generic Core Scales. Results  While the four-factor conceptually-derived measurement model for the PedsQL™ 4.0 Generic Core Scales produced an acceptable fit, the five-factor empirically-derived measurement model from the initial field test of the PedsQL™ 4.0 Generic Core Scales produced a marginally superior fit in comparison to the four-factor model. For the five-factor measurement model, the best fitting model, strict factorial invariance of the PedsQL™ 4.0 Generic Core Scales across the two measurement occasions was supported by the stability of the comparative fit index between the unconstrained and constrained models, and several additional indices of practical fit including the root mean squared error of approximation, the non-normed fit index, and the parsimony normed fit index. Conclusion  The findings support an equivalent factor structure on the PedsQL™ 4.0 Generic Core Scales over time. Based on these data, it can be concluded that over a one-year period children in our study interpreted items on the PedsQL™ 4.0 Generic Core Scales in a similar manner. The PedsQL™ is available at .     

Rasch Analysis of the Pediatric Quality of Life Inventory 4.0 Generic Core Scales Administered to Patients With Duchenne Muscular Dystrophy

ObjectivesThe objective of this study was to examine the psychometric properties of the Pediatric Quality of Life Inventory 4.0 Generic Core Scales (PedsQL 4.0 GCS) in Duchenne muscular dystrophy (DMD), a rare, severely debilitating, and ultimately fatal neuromuscular disease.MethodsPatients with DMD were recruited from 20 centers across 9 countries as part of the Cooperative International Neuromuscular Research Group Duchenne Natural History Study (NCT00468832). The psychometric properties of the PedsQL 4.0 GCS were examined using Rasch analysis.ResultsIn total, 329 patients with DMD (mean age 9 years, range 3–18 years, 75% ambulatory) completed the PedsQL 4.0 GCS. The most difficult instrument items, expressing the greatest loss in health-related quality of life, were those associated with emotional well-being (eg, being teased by other children, feeling sad, and not making friends), as opposed to somatic disability (eg, lifting heavy objects, participating in sports, and running). The mean item and person fit residuals were estimated at 0.301 (SD: 1.385) and −0.255 (1.504), respectively. In total, 87% (20 of 23) of items displayed disordered thresholds, and many exhibited nontrivial dependency. The overall item-trait interaction χ² value was 178 (115 degrees of freedom, P<.001). Our analysis also revealed significant issues with differential item functioning, and by investigating residual principal component loadings, the PedsQL 4.0 GCS total score was found to be multidimensional.ConclusionsThe PedsQL 4.0 GCS records information clinically relevant to patients with DMD, but the total scale score may not be fit for purpose as a measure health-related quality of life in this disease population.     

Measuring health-related quality of life in Greek children: psychometric properties of the Greek version of the Pediatric Quality of Life Inventory<Superscript>TM</Superscript> 4.0 Generic Core Scales

Objectives The aim of this study was to investigate the psychometric properties of the Greek version of the Pediatric Quality of Life Inventory^TM 4.0 (PedsQL^TM 4.0) as a population health outcome measure. Methods After cultural linguistic validation, a cross-sectional study with the participation of 645 children (8–12 years old) and their primary caregivers was conducted in a nation-wide representative school-based sample to evaluate the psychometric properties of the measure. Results All PedsQL 4.0 scales showed satisfactory reliability, with Cronbach’s α exceeding 0.70—except in self-reported Physical Functioning (α = 0.65). Test–retest stability intraclass correlation coefficients (ICCs) were above 0.60 in all subscales. No floor effects were detected in either the self-report or parent proxy versions. Ceiling effects ranged from 2.2% (self-report Total Score) to 31.1% (parent-report Social Functioning). Poor to moderate agreement between self report and proxy report was observed, especially for the younger age groups of children. Impact of gender, health status, and family affluence status were detected, as hypothesised from previous bibliography, with girls reporting lower health-related quality of life (HRQOL) than boys on the Emotional Functioning subscale, healthy children scoring significantly higher on all scales than those with chronic illnesses, and lower socioeconomic groups scoring significantly lower than higher socioeconomic groups. Factor analysis showed mainly comparable results with the original version. Conclusions Present results support the reliability and validity of the PedsQL 4.0 Greek version. The instrument could be a valuable tool in HRQOL measurement in school health care settings and population-based studies in Greek-speaking children, though it should be stressed that when possible, the child should be considered the first informant of his/her HRQOL.