Reliability, Convergent and Discriminant Validity of the Persian Version of Cystic Fibrosis Questionnaire-Revised in Cystic Fibrosis Children

Abstract

Introduction: Cystic fibrosis is a genetic disease that affects the respiratory and gastrointestinal organs. CF has a chronic, progressive and debilitating nature, so it is important to examine the quality of life in these individuals. The CFQ-R, a universal tool for measuring these patients' quality of life, was the most validated and used in CF-related studies. The purpose of this study was to evaluate the convergent and discriminant validity, reliability (test-retest and internal consistency) and the ceiling-floor effect of the Persian version of CFQ-R child and parents’ version. Materials and Methods: In this study, CFQ-R child and parent was completed by fifty children with CF and their parents. Convergent and discriminant validity, reliability (test-retest and internal consistency) and ceiling-floor effect of these two versions were then evaluated. For convergent validity, questionnaire domains were compared with similar domains in the PedsQL questionnaire. For the test-retest, 30 study participants were asked to complete the questionnaire again. Results: The results showed acceptable convergent and discriminant validity in some areas of the two versions of the questionnaire. Also acceptable reliability was observed for both versions. The ceiling-floor effect was not seen in most areas of the two versions. Conclusion: The child and parent versions of the CFQ-R questionnaire have acceptable validity and reliability and can be used in future clinical trials and comparisons of results with those of other countries.