title: [The Montreal definition and classification of gastroesophageal reflux disease: a global, evidence-based consensus paper].
abstract: OBJECTIVE
  A world-wide recognised and accepted definition and classification of gastroesophageal reflux disease (GERD) would be highly desirable for research and clinical practice. The purpose of this project was to develop such a generally accepted definition and classification that could be used equally by patients, physicians, and supervisory bodies.
  
  
  METHODS
  In order to ensure a consensus among the participating experts a modified delphi process with a step-wise selection modality was employed. For this the working group of five persons formulated a series of statements on the basis of a systematic search of the literature using three databases (Embase, Cochrane-Study register, Medline). Then these statements were developed further for two years, revised and finally passed as consensus. The consensus group consisted of 44 experts from 18 countries. Each key vote was held on the basis of a six-point scale. A "consensus" was considered to have been reached when two-thirds of the participants voted in favour of the respective statement.
  
  
  RESULTS
  The level of agreement between the experts increased in the course of the multistep decision process, in the individual voting steps requiring at least two-thirds of the participants, the results were at first 86%, then 88% through to 94% and finally 100% in favour of the chosen statement. In the final voting, 94% of the final 51 statements were accepted by 90% of the consensus group. 90% of all statements were accepted unanimously or with only minor reservations. GERD was defined as a disease that is associated with troublesome symptoms and/or complications on account of reflux of stomach contents into the esophagus. The complaints are divided into esophageal and extra-esophageal syndromes. Among the novel aspects of this definition are the patient-orientated approach that is independent of endoscopic findings, the classification of the ailment into independent syndromes as well as the consideration of laryngitis, cough, asthma and dental problems as possible GERD syndromes. Furthermore, a new definition of suspected or demonstrated Barrett's esophagus is proposed.
  
  
  CONCLUSIONS
  Irrespective of country-specific differences in terminology, language, prevalence and manifestations of this disease, evidence-based, world-wide valid consensus definitions are possible. A global consensus definition of GERD will simplify disease management, make mutual research possible and help in the design of generally valid studies. This will not only help the patient but also the physician and supervisory bodies.
authors.affiliation: University of Wisconsin School of Medicine and Public Health, Madison, Milwaukee, Wisconsin 53233, USA.
authors.forename: N
authors.initials: N
authors.lastname: Vakil
authors.forename: S V
authors.initials: SV
authors.lastname: van Zanten
authors.forename: P
authors.initials: P
authors.lastname: Kahrilas
authors.forename: J
authors.initials: J
authors.lastname: Dent
authors.forename: R
authors.initials: R
authors.lastname: Jones
mesh_terms: D019317:Evidence-Based Medicine; D005764:Gastroesophageal Reflux / Q000145:classification*; D006801:Humans; D038622:Internationality; D009626:Terminology as Topic