Quality of life in patients with chronic rhinosinusitis. Validation of the Sino-Nasal Outcome Test-20 German Adapted Version

Background. No validated German instrument for measuring health-related quality of life (QOL) in patients with chronic rhinosinusitis (CRS) has been available to date. Material and Methods. The Sino-Nasal Outcome Test-20 German Adapted Version (SNOT-20 GAV) is a translated and adapted version of SNOT-20. To validate this instrument, we evaluated its reliability, validity and sensitivity. SNOT-20 GAV was completed by 163, 123, and 82 patients at the initial visit and at 3 months and 1 year after treatment commencement, respectively. Results. Cronbach's alpha indicated good internal consistency. Test-retest scores in 38 patients were highly correlated. Discrimination validity was demonstrated by a comparison with healthy controls. Sensitivity to change showed medium to large effects. Conclusions. SNOT-20 GAV is the first reliable, validated and sensitive German instrument for measuring health-related QOL in patients with CRS.