Translation and linguistic validation of a disease-specific quality of life measure for cystic fibrosis

Objective: To develop a conceptually and semantically valid English version of a French disease-specific measure of quality of life for children, adol escents, and adults with cystic fibrosis (CF). Methods: Following a backward and forward translation of the measure, 60 pa rticipants, including 20 children, 20 parents, and 20 adolescents/young adu lts completed the Cystic Fibrosis Questionnaire (CFQ) and a series of cogni tive probes evaluating their understanding of the items and response choice s. Results: Semantic and conceptual problems with the items were identified an d modified for the second set of cognitive interviews. Response distributio ns across items and ages were adequate, and the predicted associations betw een disease severity and quality of life were obtained. Conclusions: The English version of the CFQ appears to be a linguistically valid measure of quality of life for patients with CF. A national validatio n study is now under way to test the psychometric properties of the measure .