Cross-Cultural Adaptation and Validation of SNOT-20 in Portuguese.

Introduction. Chronic rhinosinusitis is a highly prevalent disease, so it is necessary to create valid instruments to assess the quality of life of these patients. The SNOT-20 questionnaire was developed for this purpose as a specific test to evaluate the quality of life related to chronic rhinosinusitis. It was validated in the English language, and it has been used in most studies on this subject. Currently, there is no validated instrument for assessing this disease in Portuguese. Objective. Cross-cultural adaptation and validation of SNOT-20 in Portuguese. Patients and Methods. The SNOT-20 questionnaire underwent a meticulous process of cross-cultural adaptation and was evaluated by assessing its sensitivity, reliability, and validity. Results. The process resulted in an intelligible version of the questionnaire, the SNOT-20p. Internal consistency (Cronbach's alpha = 0.91, P < .001), reliability testing-retesting (r = 0.994, P < .001), content validity, validity of discrimination of patients without chronic rhinosinusitis (U = 44, P < .0001) and assessment of sensitivity to change (SRM = 1.53 and 1.09) were evaluated. Conclusion. We conducted a successful process of cross-cultural adaptation and validation of the SNOT-20 questionnaire into Portuguese.