Validation of the Korean Version of the “Empty Nose Syndrome 6-Item Questionnaire (ENS6Q)”

Background and Objectives Empty nose syndrome (ENS) is difficult to diagnose because objective findings often do not correlate with symptom severity.The Empty Nose Syndrome 6-item Questionnaire (ENS6Q) has been developed to assess ENS-specific symptoms, but there has not been sufficient verification research for a Korean version.Subjects and Method A Korean version of the ENS6Q (ENS6Q-KAV) was administered twice to patients with ENS, normal controls, and patients with chronic rhinosinusitis (CRS).Known-groups validity was evaluated using the Kruskal-Wallis test followed by the Bonferroni-corrected post-hoc analyses.Reliability was assessed using Cronbach's α and the intraclass correlation coefficient [ICC(3,1)].Diagnostic accuracy was evaluated using the receiver operating characteristic (ROC) analysis.Results ENS6Q-KAV total scores differed significantly among the three groups at both administrations (H=57.86 and 61.34, respectively; p<0.001), with the ENS group showing significantly higher scores than both the normal control and CRS groups.All item scores were also significantly higher in the ENS group (adjusted p<0.001).Internal consistency was high (Cronbach's α=0.861-0.884),and test-retest reliability was excellent (ICC=0.937;95% confidence interval, 0.914-0.955).ROC analysis demonstrated excellent discrimination between ENS and normal controls (area under the curve [AUC]=0.948-0.962)and robust discrimination between ENS and CRS (AUC=0.915-0.931),with an optimal cut-off score of 9. Conclusion The ENS6Q-KAV is a reliable and valid tool for assessing ENS-specific symptoms and effectively distinguishes ENS from normal controls and CRS in Korean-speaking patients.