Sino-Nasal Outcome Test-22: translation, cross-cultural adaptation, and validation in Polish-speaking patients

Abstract

Abstract Purpose There are many specific instruments for assessing the quality of life (QoL) in patients with chronic rhinosinusitis. Of all these tests, the Sino-Nasal Outcome Test–22 (SNOT-22) is the most widely used internationally. The purpose of the study was linguistic adaptation and validation of the SNOT-22 scale in the Polish language. Methods The SNOT-22 was adapted into Polish and was administered to 148 subjects (108 patients with chronic rhinosinusitis with nasal polyps (CRSwNP) and 40 asymptomatic controls. Seventy-one patients completed the SNOT-22 a second time to evaluate test-retest reliability. The Polish SNOT-22 was assessed for internal consistency, test-retest reliability, discriminant validity, criterion validity, and sensitivity and specificity. Results The Polish SNOT-22 exhibited satisfactory psychometric properties. A high Cronbach’s alpha coefficient (α = 0.89) was obtained. Significantly higher scores (p < 0.01) were revealed in the Study Group with a median score of 32 (range 15–53) points in comparison with controls: 5 (range 0–20). A moderate correlation was found between SNOT-22 and the Lund-Kennedy test score (r = 0.334; p < 0.001) and a strong correlation between SNOT-22 and the Lund–Macay test score (r = 0.469; p < 0.001). The best cut-off point was set at a 16 score with a sensitivity of 0.981 and a specificity of 0.995. The determined Area Under Curve (AUC = 0.997; p < 0.001) confirms the diagnostic accuracy of the Polish SNOT-22. Conclusions The Polish version of the SNOT-22 is a valid and reliable tool for measuring health-related quality of life in patients with CRSwNP in the Polish-speaking population.