Subjects and study design
In this study, we retrospectively reviewed patients diagnosed with LPR via 24hr MII-pH monitoring. Examiners advised to all patients to keep their common diet during 24hr MII-pH monitoring. Patients with typical reflux symptoms and ≥ 1 objective pharyngeal reflux episode were classified as LPR patients.11 LPR symptoms were assessed using the reflux symptom index (RSI).12 The objective pharyngeal reflux episode was assessed using 24hr MII-pH monitoring.13 Finally, we enrolled 69 LPR patients whose test time of 24-hour MII-pH monitoring could be estimated, and raw recording files could be accessible. Additionally, we recruited normal controls without reflux-related symptom. 24hr MII-pH monitoring was performed on the healthy controls. The time of pharyngeal reflux episodes in the healthy controls was analyzed and compared with the LPR patients. This study was approved by Institutional Review Board of OOO.