A preliminary validation of the Swedish version of the Pain Catastrophizing Scale for Children (PCS-C) for children and adolescents with cancer.

Objectives: Pain is reported as one of the most common and difficult symptoms for children and adolescents with cancer to cope with. Pain catastrophizing has been identified as a process clearly related to pain intensity and disability. The Pain Catastrophizing Scale for Children (PCS-C) has been validated in several languages and populations but remains to be validated in pediatric oncology. The aim of the study was to validate a Swedish version of the PCS-C for children and adolescents with cancer. Methods: All children, 7-18 years of age, being treated for cancer in Sweden at the time of the study were invited to participate. Study material was sent out to the registered address. Internal consistency, test-retest reliability and convergent validity were calculated. Factor structure was examined using principal component analysis (PCA). Descriptive statistics were used to investigate background data and norm values. Results: 61 children/adolescents were included in the analyses. The results did not support the original three-factor structure of the PCS-C, but rather suggested that a two-factor structure excluding item 8 best represented the data. The internal consistency of that solution was good (alpha=0.87), the test-rest reliability was excellent (ICC=0.75) and convergent validity was demonstrated (r=0.46). The mean (SD) for the PCS-C in the sample was 19.1 (9.2), without item 8. A statistically significant difference was shown between genders, where girls reported a higher level of pain catastrophizing than boys. No difference was found with regard to age. Discussion: The Swedish version of the PCS-C is now preliminarily validated for children and adolescents with cancer, for whom gender- and age-specific norm values are now available. Questions remain regarding the optimal factor structure of the PCS-C.