Aim: To study the psychometric performance of the Swedish version of the Pediatric Quality of Life Inventory (PedsQL) 4.0 generic core scales in a general child population in Sweden.
Methods: PedsQL forms were distributed to 2403 schoolchildren and 888 parents in two different school settings. Reliability and validity was studied for self-reports and proxy reports, full forms and short forms. Confirmatory factor analysis tested the factor structure and multigroup confirmatory factor analysis tested measurement invariance between boys and girls.
Results: Test-retest reliability was demonstrated for all scales and internal consistency reliability was shown with alpha value exceeding 0.70 for all scales but one (self-report short form: social functioning). Child-parent agreement was low to moderate. The four-factor structure of the PedsQL and factorial invariance across sex subgroups were confirmed for the self-report forms and for the proxy short form, while model fit indices suggested improvement of several proxy full-form scales.
Conclusion: The Swedish PedsQL 4.0 generic core scales are a reliable and valid tool for health-related quality of life (HRQoL) assessment in Swedish child populations. The proxy full form, however, should be used with caution. The study also support continued use of the PedsQL as a four-factor model, capable of revealing meaningful HRQoL differences between boys and girls.