[Rasch Model in the Validation of the Paediatric Quality of Life Inventory™ 4.0 (PedsQL 4.0™) in Colombian Children and Adolescents].

INTRODUCTION: The aim of this study was to validate the PedsQL 4.0™ in Colombian children and adolescents using the Rasch model. The Paediatric Quality of Life Inventory (PedsQL 4.0™) has demonstrated to be a reliable and sensitive measurement to changes in health status, as well as being quick and easy to use.

METHODS: Validation study of measurement tools. The PedsQL 4.0™ was applied to a convenience sample of 375 children and adolescents between 5 and 17 years old and 500 caregivers of children between 2 and 18 years old in five Colombian cities. The psychometric properties were analysed according to the Rasch model, including adjustment, separation, and differential item functioning (DIF).

RESULTS: The Rasch model provided adequate fits to data. The social dimension, for both versions, had greater difficulty than the physical health dimension. Internal consistency for the items was observed, while for individuals, the values of reliability and separation were lower than that established. The DIF occurred in very few variables, especially when comparing cities. The characteristic curves for the items presented disordered thresholds.

CONCLUSIONS: The items had adequate internal consistency. Analysis showed adequate individual separation, but disordered thresholds were found in the response categories. No DIF was observed by sex or disease, but it is noteworthy that the DIF occurred between cities.