Diagnostic accuracy of nasal cannula versus microphone for detection of snoring

Objective Snoring is a common reason for referral to a sleep unit. Although there are several instruments to measure snoring, there is no gold standard for this purpose. In this study, we determine the diagnostic accuracy of the cannula as compared with the microphone, which are the two most commonly used tools. Study Design We performed a cross-sectional study of 75 patients who underwent baseline home sleep apnea testing for any reason. Methods Snore intensity and percentage were assessed during Home sleep-apnea testing via nasal cannula and microphone in all patients. We performed a complete diagnostic accuracy analysis, assuming the microphone to be the reference instrument use in order to compare it with the cannula. Results The intra-class correlation coefficient between the cannula and microphone for the percentage of snoring was 0.25. The Bland Bland-Altman analysis to determine the agreement regarding the percentage of snoring showed a lower limit of −57.73 and an upper limit of 20.30. A linear regression analysis of the differences produced a negative slope of −0.86. The receiver operating characteristic curve for severe snoring using the cannula produced an area under the curve of 0.67 (P = 0.019). The cannula showed a sensitivity of 57.89 and a specificity of 73.21. Conclusion The nasal cannula showed poor reliability and accuracy for measuring snoring. Level of Evidence 2b. Laryngoscope, 2017