Results: Totally, we surveyed 19,360 patients, 17,228 patients (Male 43.9%, Female 56.1%) were included, the response rate is 89.0%. Among them, 2 501 (14.5%) patients’ GerdQ score

was ≧ 8, and 1,052 patients accepted the upper endoscopy for upper GI system. For patients with the upper endoscopy, 170 patients were diagnosed as Reflux Esophagitis (RE) or Barrett’s Esophagus (BE), and 10 patients were diagnosed as gastric or esophageal cancer. 14 727 patients’ GerdQ score was < 8, and 3,482 patients accepted the upper endoscopy; 315 patients were diagnosed as RE or BE and 44 patients were diagnosed as gastric or esophageal cancer by the endoscope. Conclusion: The prevalence of symptom-defined GERD was 14.5% in Digestive Fulvestrant Department of PKU Third MI-503 mw Hospital, higher than previous surveys of GERD in our country. Because our respondents were outpatients from digestive department and they had more digestive tract symptoms than the general population. Combined with upper endoscopy results, the patients with high GerdQ cannot be excluded from the malignancies, and the patients with low GerdQ may be diagnosed as RE or BE. Key Word(s): 1. GERD diagnosis; 2. GerdQ; 3. symptoms; 4. prevalence; Presenting Author: ZHOU LIYA Additional Authors: WANG YE, LIN SANREN, LU JINGJING, LIN LIN,

CHEN WHENKE Corresponding Author: LIN SANREN Affiliations: Peking University Third Hospital Objective: The aim of this study was to assess the performance of 24-h esophageal impedance monitoring in diagnosis of gastroesophageal reflux disease (GERD). Methods: The patients suspected of GERD that were admitted to our hospital during the period from 1st September, 2011 through 31th December, 2012 were enrolled in this study. All subjects received endoscopic examination, 24-h pH-impedance monitoring. Presence of reflux esophagitis or Barrett’s esophagus detected using endoscopy

or abnormal 24-h pH monitoring served as the reference standard for diagnosis of GERD, and the diagnostic validity of the 24-h esophageal impedance monitoring was assessed. Results: Totally 667 subjects were enrolled in this study, and 636 cases (95.4%) who received all examinations were involved in the final analysis, including 352 cases (52.8%) 上海皓元 with diagnosis of GERD. There were significant differences in total reflux events (Z = -8.12, P = 0.00), acid reflux events (Z = -10.83, P = 0.00) and weakly alkaline reflux events (Z = -2.163, P = 0.031) between the GERD and non-GERD patients, while no significant difference in weakly acid reflux events was detected. The sensitivity and specificity of 24-h impedance monitoring for diagnosis of GERD were 66.5% and 43.7%, respectively. Of the 373 patients with negative pH-monitoring test, the sensitivity and specificity of 24-h impedance monitoring for diagnosis of GERD were 75.3% and 43.