CRS Questionnaire Validation Project

The 'CRS validation project' consists of a joint effort of 32 medical centers in Europe, the USA, and South Africa to carry out the validation of 2 novel questionnaires designated to measure self-perceived severity and control of Chronic Rhinosinusitis (with or without nasal polyps). This study will validate translated versions of the same set of questionnaires simultaneously in the centers involved after recruiting a total of 1000 patients, while data collection, statistical analysis, and creation of the study report will be carried out by the statistical department of the University of Leuven. Patients will be recruited from the regular ENT practice of their hospital to minimize the complexity of the study.

Inclusion Criteria: * Patient capable of giving informed consent * Diagnosis of chronic rhinosinusitis with or without nasal polyposis according to the EPOS guidelines * No recent sinus surgery (within the last three months) Exclusion Criteria: * Not capable of giving informed consent * No CRS * Recent sinus surgery (within the last three months)