Reliability and validity assessments of a Japanese version of QOL 20-Item Sino-Nasal Outcome Test for chronic rhinosinusitis

Abstract

Objective: The objective of this study was to assess the reliability and validity of a Japanese version of the 20-Item Sino-Nasal Outcome Test SNOT-20, which is one of the quality-of-life (QOL) evaluation sheets for chronic rhinosinusitis (CRS), and assess its reliability and validity.

Methods: The SNOT-20 was conducted in patients with CRS and in healthy volunteers. The response rate was evaluated as the feasibility of this test, and reliability and internal consistency were assessed as reliability. In addition, concurrent validity and discriminant validity were assessed as validity.

Results: Regarding the feasibility of this test, the response rate for each question item in the SNOT-20 was nearly 100% for all 20 items. For reliability, test-retest reliability was r=0.890 and the internal consistency was alpha=0.903. For validity, the concurrent validity was r=0.162 when compared with objective findings in the nasal cavity, and was r=0.431 when compared with the score for general physical condition, which evaluate the patient's general condition. Discriminant validity was significantly higher in patients with CRS than in healthy volunteers (p<0.001). Moreover, when the discriminant validity was assessed using an ROC (receiver operating characteristic) curve, it was found that ROC-AUC (the area under the curve)=0.775.

Conclusion: The reliability and validity of a Japanese version of the SNOT-20 were assessed in this study. It is thought that the SNOT-20 serves as a useful QOL evaluation sheet for CRS.