title: Streamlining 24-hour pH study for GERD: Use of a 3-hour postprandial test.
abstract: At present, the ambulatory 24-hr pH test has been used as a diagnostic tool to assess gastroesophageal reflux disease (GERD) in those patients with reflux symptoms and a normal endoscopy. However, patients poorly tolerate the prolonged nature of the 24-hr test. The aim of this study was to determine whether analyzing a 3-hr postprandial period from a full 24-hr study would be as sensitive as the longer test. Data were analyzed from a standard ambulatory 24-hr pH recording. A positive test was determined if the pH was < 4 for more than 4% of the study period with the probe placed 5 cm above the lower esophageal sphincter for both groups. The data were then reanalyzed by determining the percent time of pH < 4 during a 3-hr postprandial period. The results of 50 patients with a positive 24-hr test were compared with 50 patients with normal tests. The meal that was used to study the 3-hr postprandial period occurred in the late afternoon or early evening. The 3-hr postprandial test had a sensitivity of 88% when compared to the 24-hour test and a specificity of 98%. The positive predictive value was 100% for the 3-hr test, and the accuracy of this shorter test when compared with the standard 24-hour test was 95%. In conclusion the 3-hr postprandial analysis is a highly sensitive and specific test for demonstrating GERD. By using the shorter test, patient discomfort may be reduced and compliance enhanced.
authors.affiliation: Department of Gastroenterology and Hepatology, Mayo Clinic and Foundation, 200 First Street SW, Rochester, Minnesota 55905, USA.
authors.forename: Amindra S
authors.initials: AS
authors.lastname: Arora
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Murray
mesh_terms: D016022:Case-Control Studies; D005764:Gastroesophageal Reflux / Q000175:diagnosis*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D018670:Monitoring, Ambulatory / Q000379:methods*; D019518:Postprandial Period; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013997:Time Factors