Cross-cultural adaptation and validation of the 22-item sinonasal outcome test (SNOT-22) in German-speaking patients: a prospective, multicenter cohort study

PURPOSE: Chronic rhinosinusitis (CRS) is a common condition associated with a significant reduction of the health-related quality of life. One of the most widely used assessment tools in CRS is the disease-specific, health-related questionnaire SNOT-22. The aim of this study was to translate and validate the SNOT-22 into the German language.

METHODS: The questionnaire was translated using the forward-backward translation technique. After the translation its reliability, validity, and sensitivity were evaluated. For this purpose, the questionnaire was completed by patients diagnosed with CRS before, 3 months and 1 year after endoscopic sinus surgery and by healthy individuals as controls at three university hospitals in Germany. The individual scores of the questionnaire before surgery was correlated with the Lund-Mackay score as well as a global disease-specific question.

RESULTS: A total of 139 CRS patients and 31 healthy individuals participated in the study. Internal consistency at all timepoints was very good, with Cronbach's alpha scores of 0.897, 0.941, and 0.945. The questionnaire was able to discriminate between CRS patients and control subjects (p < 0.0001) and scores improved significantly 3 month and 1 year after sinus surgery (p < 0.0001), indicating a good test-retest reliability, validity, and responsiveness. A significant correlation to the single global disease-specific question could be found (p < 0.0001), but no correlation with the Lund-Mackay score.

CONCLUSION: The German Version of the SNOT-22 is a reliable, valid, and sensitive instrument for measuring health-related quality of life in patients with CRS. It can be recommended for clinical practice and outcome research for German-speaking patients.