title: pH Impedance vs. traditional pH monitoring in clinical practice: an outcome study.
abstract: BACKGROUND
  The addition of impedance to 24-h pH monitoring has allowed detection of weakly acidic reflux, but the extent to which pH-impedance (pH-MII) monitoring improves outcomes is unknown.
  
  
  METHODS
  This was a prospective observational study. Patients referred for pH or pH-MII monitoring completed a standardized questionnaire on improvement in the dominant symptom, their satisfaction, and treatment at 3 and 12 months after the test during a telephone interview.
  
  
  RESULTS
  A total of 184 patients (mean age, 52 years, range, 19-82 years; 35 % with typical symptoms; and 89 % tested off therapy) completed pH (n = 92) or pH-MII monitoring (n = 92) over a period of 15 months. The two arms were similar in terms of demographic, clinical, and endoscopic variables. Ten patients in the pH-MII arm showed evidence of weakly acidic reflux disease. There was no difference in the percentage of patients in the pH and pH-MII monitoring arms who experienced improvement in their dominant symptom after 3 (58 vs. 63 %; p = 0.621) or 12 months (66 vs. 70 %; p = 0.234), and the same was true for patient satisfaction. There were also no between-group difference in the use of proton pump inhibitors (PPIs) after 3 (63 vs. 68.5 %; p = 0.437) or 12 months (47 vs. 60.5 %; p = 0.051). PPIs were prescribed more frequently after a positive test (p < 0.001) although they were used by 45.6 % of the negative patients. Only one patient underwent fundoplication.
  
  
  CONCLUSIONS
  Two-thirds of patients undergoing pH-MII monitoring experience a positive outcome, similarly to what occurs after traditional pH monitoring. Physicians often pay little attention to the test results, especially if they are negative.
authors.affiliation: Gastroenterology and Endoscopy Unit, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Via della Commenda 19, 20122, Milan, Italy. delia.pugliese@unimi.it.
authors.forename: Delia
authors.initials: D
authors.lastname: Pugliese
authors.affiliation: Gastroenterology and Endoscopy Unit, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Via della Commenda 19, 20122, Milan, Italy.
authors.forename: Aurelio
authors.initials: A
authors.lastname: Mauro
authors.affiliation: Epidemiology Unit, Department of Preventive Medicine, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, via Francesco Sforza 35, 20122, Milan, Italy.
authors.forename: Dario
authors.initials: D
authors.lastname: Consonni
authors.affiliation: Gastroenterology and Endoscopy Unit, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Via della Commenda 19, 20122, Milan, Italy.
authors.forename: Ivana
authors.initials: I
authors.lastname: Bravi
authors.affiliation: Gastroenterology and Endoscopy Unit, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Via della Commenda 19, 20122, Milan, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Tenca
authors.affiliation: Gastroenterology and Endoscopy Unit, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Via della Commenda 19, 20122, Milan, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Elvevi
authors.affiliation: Gastroenterology and Endoscopy Unit, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Via della Commenda 19, 20122, Milan, Italy.
authors.forename: Dario
authors.initials: D
authors.lastname: Conte
authors.affiliation: Gastroenterology and Endoscopy Unit, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Via della Commenda 19, 20122, Milan, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Penagini
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017097:Electric Impedance; D050782:Esophageal pH Monitoring / Q000379:methods*; D004945:Esophagoscopy; D005764:Gastroesophageal Reflux / Q000175:diagnosis* / Q000628:therapy; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000379:methods; D017060:Patient Satisfaction; D011446:Prospective Studies; D016896:Treatment Outcome; D055815:Young Adult
keywords: Gastroesophageal reflux; Impedance-pH monitoring; Patient’s outcome