title: Diagnostic accuracy of nodular gastritis for H. pylori infection.
abstract: BACKGROUND
  The term nodular is not included in the Sydney classification and there is no widely accepted histopathological definition. It has been proposed that the presence of antral nodularity could predict Helicobacter pylori (H. pylori) infection. The aim of this study was to determine the diagnostic accuracy of nodular gastritis (NG) for H. pylori infection after a rigorous standardization process, and to describe the associated histopathological characteristics.
  
  
  METHODS
  Endoscopic images of patients submitted to endoscopy with biopsy sampling were included. Endoscopic images were distributed among six endoscopists. The analysis was performed sequentially in three rounds: the first round assessed the interobserver variability, the second evaluated the intraobserver variability, and the third calculated the interobserver variability after training. A correlation analysis between endoscopic and histopathological findings was performed.
  
  
  RESULTS
  A total of 917 studies were included. In the first analysis of interobserver variability, a poor kappa value (0.078) was obtained. The second evaluation yielded good intraobserver variability, with kappa values of 0.62-0.86. The evaluation of interobserver variability after training revealed an improvement in the kappa value of 0.42. A correlation was found between endoscopic images and histopathological reports.
  
  
  CONCLUSIONS
  There was a strong correlation between NG and H. pylori, but only after rigorous evaluation. The use of the term NG requires extensive standardization before it can be used clinically.
authors.affiliation: Obesity and Digestive Diseases Unit, Medica Sur Clinic & Foundation.
authors.forename: Juan L
authors.initials: JL
authors.lastname: Romero-Flores
authors.affiliation: Obesity and Digestive Diseases Unit, Medica Sur Clinic & Foundation.
authors.forename: Justo A
authors.initials: JA
authors.lastname: Fernandez-Rivero
authors.affiliation: Obesity and Digestive Diseases Unit, Medica Sur Clinic & Foundation.
authors.forename: Erika
authors.initials: E
authors.lastname: Marroquín-Fabian
authors.affiliation: Department of Gastrointestinal Endoscopy, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán.
authors.forename: Félix I
authors.initials: FI
authors.lastname: Téllez-Ávila
authors.affiliation: Obesity and Digestive Diseases Unit, Medica Sur Clinic & Foundation.
authors.forename: Beatriz A
authors.initials: BA
authors.lastname: Sánchez-Jiménez
authors.affiliation: Translational Research Unit, Medica Sur Clinic & Foundation, Mexico City, Mexico.
authors.forename: Eva
authors.initials: E
authors.lastname: Juárez-Hernández
authors.affiliation: Obesity and Digestive Diseases Unit, Medica Sur Clinic & Foundation.
authors.forename: Misael
authors.initials: M
authors.lastname: Uribe
authors.affiliation: Obesity and Digestive Diseases Unit, Medica Sur Clinic & Foundation; Translational Research Unit, Medica Sur Clinic & Foundation, Mexico City, Mexico.
authors.forename: Norberto C
authors.initials: NC
authors.lastname: Chávez-Tapia
keywords: endoscopy; histopathologic; sensitivity; specificity