Abstract
This study was designed to validate a grading scheme for lateral nasal wall insufficiency with interrater and intrarater reliability measures. Representative endoscopic videos depicting varied degrees of lateral nasal wall insufficiency were collated into a 30-clip video (15 clips in duplicate). This was rated by five reviewers for a total of 150 observations. Interrater and intrarater reliability were determined using Fleiss kappa and intraclass correlation coefficient (ICC) statistics, respectively. Good agreement was established between reviewers (interrater reliability), with a Fleiss kappa of 0.7733 (p < 0.01). Analysis of intrarater variability with the ICC revealed a very strong agreement (ICC = 0.88; p < 0.01). The proposed grading system is shown to have good interrater and intrarater reliability. It provides a reliable instrument for assessing lateral wall insufficiency.