How subjective is nasal endoscopy? A study of interrater agreement using the Lund and Mackay scoring system

Background: Scoring systems exist to standardize the recording of nasal endoscopy findings. The extent to which two surgeons will agree on the findings of nasal endoscopy in adults currently is unknown, although a study in children showed high rates of agreement between two observers. We studied the interobserver agreement of adult nasal endoscopy scored with the system proposed by Lund and Mackay. Method: A consecutive series of otolaryngology patients attending with a variety of nasal complaints were recruited. All were examined with a 0degrees 4-mm endoscope by two surgeons on the same clinic visit. Each independently recorded their findings using the Lund and Mackay scoring system. Neither surgeon was aware of the other's findings. Results: Thirty patients were studied (16 women and 14 men). Because the endoscopic findings were recorded separately for each side of the nose, each surgeon made 60 observations. Interrater agreement was calculated as Cohen's K, and suggested moderate agreement for edema (kappa = 0.45), good agreement for crusting (kappa = 0.62), and very good agreement for Polyp (kappa = 0.93) and discharge (kappa = 0.84). Conclusion: Two independent observers agree on the findings of nasal endoscopy in a high proportion of cases. Nasal endoscopy is a reliable tool, especially when a scoring system such as that of Lund and Mackay is used.