CROSS-CULTURAL ADAPTATION AND VALIDATION OF LEICESTER COUGH QUESTIONNAIRE IN SARCOIDOSIS: THE PERSIAN VERSION

Background and aim: Cough is a common symptom among patients with sarcoidosis, and the Leicester Cough Questionnaire, a cough -specific quality -of -life measure, evaluates the impact of cough across physical, psychological, and social domains in patients with chronic cough. The aim of this study was cross-cultural adaptation and validation of Persian version of Leicester Cough Questionnaire (LCQ) in pulmonary sarcoidosis in Iran. Methods: Psychometric analyses included translation and back translation of the questionnaire, face validity, content validity, construct validity, criterion -related validity, internal consistency, and test -retest reliability were performed. Results: Twenty-five participants demonstrated no major language barriers or difficulties in completing the questionnaire and adequate face validity of >= 1.5. Twelve experts confirmed the content validity was good (CVR>0.56, I-CVI <= 0.79, S-CVI/Ave>0.80). Totally, 190 patients were included in the study. The Pearson's coefficients and their significance's (P<0.05) showed an acceptable agreement between the LCQ and the SF -36 questionnaire. The goodness -of -fit of the conceptual model including psychological, physical, and social domains, obtained from EFA, was confirmed throughout the RMSEA of 0.09 (<0.1), NFI of 0.9, NNFI of 0.91, and CFI of 0.92 which all were >= 0.9. The Persian LCQ showed an excellent internal consistency regarding Cronbach's alpha of 0.974 and ICC (95%CI) value of 0.983 (0.977, 0.987). Conclusions: The psychometric properties showed that the Persian version of LCQ is a valid and reliable measure to evaluate cough -specific quality of life and is a fit -for -purpose measure for use in patients with pulmonary sarcoidosis and the results can guide clinicians in treatment decisions.