Towards the Validation of the Persian Translation of the Revised Cystic Fibrosis Quality of Life Questionnaire in Adolescents and Adults (CFQ-R 14+)

Background: the present study aimed to translate the cystic fibrosis questionnaire for adolescents and adults (CFQR 14+) into Persian, and assess its validity and reliability.Methods: In total, 35 patients with cystic fibrosis (CF) completed the Persian version of CFQR 14+, and Forced Expiratory Volume in one second (FEV1) and body mass index (BMI) were measured. In addition, the Pediatric Quality of Life inventory (PedsQL) was completed by the subjects. The validity of the CFQR 14+ was assessed using the face validity, Content Validity Ratio (CVR), and Content Validity Index (CVI), along with concurrent and knowgroup validities for checking its construct validity. The scale’s reliability was also estimated by testretest and Cronbach s alpha coefficients.Results: After forwardbackward translation, the values of the total CVR and CVI and their subitems were higher than 0.8 and 0.49 respectively. Most of the scales had strong internal consistency (Cronbach s Alpha≥0.70), and the testretest correlations were within the range of 0.720.95, considered significant for all the scales. Moreover, strong correlations were observed between the total CFQR and PedsQL 4.0 (r=0.9; P lt;0.001), as well as moderatetostrong incomparable domains (r=0.40.8). A significant correlation was denoted between the total CFQR scale and FEV1 (r=0.42; P=0.01), while a reverse correlation was observed between the total CFQR scale and age group discrimination (r=0.35; P=0.03).Conclusion: According to the results, the Persian version of the CFQR 14+ is a reliable and valid instrument for measuring the healthrelated quality of life among Iranian adolescent and adult patients with CF.