Evaluation of Sinonasal Outcome Test (SNOT-22) Domains in the Assessment of the Quality of Life

Background: Few instruments are available for assessing the otorhinologic-related quality of life (QOL) in nasopharyngeal carcinoma (NPC) patients. Therefore, we evaluated whether the 22-item Sinonasal Outcome Test (SNOT-22) could be applied to these patients.Methods: Patients diagnosed with NPC, who had been treated with standard protocol and followed up in our institute between 2019 and 2022, were invited to join the cross-sectional study during their clinic visits. All participants completed the SNOT-22 and Eustachian Tube Dysfunction Questionnaire-7 once they were recruited. Confirmatory factor analysis (CFA) was performed to decide the most suitable model for the underlying SNOT-22 subdomains, along with various validity and reliability tests.Results: We identified a total of 275 patients, with 84 (30.5%) women and 191 (69.5%) men. The mean age was 54.1 years (standard deviation: 11.2). Among these patients, 171 (62.1%) were in late stages, and 260 (94.5%) received chemoradiotherapy as treatment. The median interval between primary RT treatment and questionnaire completion was 50 months (interquartile range: 29-93). CFA supported a five-factor model for the SNOT-22 for NPC patients, including nasal, ear/facial, sleep, function, and emotion domains. The internal consistency and test-retest reliability of the SNOT-22 domain score were good. In addition, known-group validity was good for the SNOT-22 total score and domain scores according to the disease recurrence status.Conclusion: Psychometric analyses supported the reliability and validity of a five-domain SNOT-22 for assessing otorhinologicrelated QOL in NPC patients.