Measuring social participation in children with chronic health conditions : validation and reference values of the child and adolescent scale of participation (CASP) in the German context

Background: While ICF-CY-based models of care are promising avenues for improving participation of children with chronic health conditions, feasible and valid instruments to assess participation as an outcome in routine are still needed. We aimed to validate a German parent-report version of the Child and Adolescent Scale of Participation (CASP) in children with chronic health conditions of different severity. Methods: Cross-sectional data were collected in 327 children (mean age 7.8 years, 55% boys) from two paediatric centres (n = 112) and one population-based sample (n = 215). Cronbach’s alpha, factor analyses, face validity assessments, correlation analyses, receiver operating characteristics (ROC) curves, and parent-reported health-related quality of life (HRQoL: KINDL) were used to examine internal consistency, test-retest reliability, and capacity to differentiate between disease severity groups. Disease severity was operationalized according to ICD-diagnosis groups and/or parent-reports on health problems, medical and educational support, and medication. A newly developed item "overall perceived participation" was added to the CASP and evaluated. Results: We found good to excellent content validity, excellent internal consistency, and good-to-excellent test-retest reliability of the instrument. While children with mild disease had a significantly greater extent of participation (higher CASP scores) than children with severe disease, they did not differ from healthy children. Children with mild compared to severe disease much more differed in participation as measured by the CASP compared to the KINDL (area under the ROC curve: 0.92 vs. 0.75). In addition, the item "overall perceived participation" was highly correlated (r = 0.86) with the CASP total score, indicating the potential value of this specific single item. Finally, we provided preliminary reference values for the CASP obtained in a population-based sample of children without chronic health conditio