title: Gastric mucosal atrophy: interobserver consistency using new criteria for classification and grading.
abstract: OBJECTIVE
  Considerable difficulties persist amongst pathologists in agreeing on the presence and severity of gastric atrophy. An international group of pathologists pursued the following aims: (i) to generate an acceptable definition and a simple reproducible classification of gastric atrophy; and (ii) to develop guidelines for the recognition of atrophy useful for increasing agreement among observers.
  
  
  METHODS
  After redefining atrophy as the 'loss of appropriate glands' and examining histological samples from different gastric compartments, three categories were identified: (i) negative; (ii) indefinite; (iii) atrophy, with and without intestinalization. Atrophy was graded on a three-level scale. Interobserver reproducibility of the classification was tested by kappa statistics (general and weighted) in a series of 48 cases.
  
  
  RESULTS
  The medians of the general agreement and weighted kappa values were 0.78 and 0.73, respectively. The weighted kappa coefficients, obtained by cross-tabulating the evaluation of each pathologist against all others, were, with only one exception, > 0.4 (moderate to excellent agreement).
  
  
  CONCLUSIONS
  By using the definition of atrophy as the loss of appropriate glands and distinguishing the two main morphological entities of metaplastic and non-metaplastic types, a high level of agreement was achieved by a group of gastrointestinal pathologists trained in different cultural contexts.
authors.affiliation: Department of Oncology and Surgical Sciences, University of Padova, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Rugge
authors.forename: P
authors.initials: P
authors.lastname: Correa
authors.forename: M F
authors.initials: MF
authors.lastname: Dixon
authors.forename: R
authors.initials: R
authors.lastname: Fiocca
authors.forename: T
authors.initials: T
authors.lastname: Hattori
authors.forename: J
authors.initials: J
authors.lastname: Lechago
authors.forename: G
authors.initials: G
authors.lastname: Leandro
authors.forename: A B
authors.initials: AB
authors.lastname: Price
authors.forename: P
authors.initials: P
authors.lastname: Sipponen
authors.forename: E
authors.initials: E
authors.lastname: Solcia
authors.forename: H
authors.initials: H
authors.lastname: Watanabe
authors.forename: R M
authors.initials: RM
authors.lastname: Genta
mesh_terms: D001284:Atrophy / Q000145:classification / Q000473:pathology; D001706:Biopsy; D005753:Gastric Mucosa / Q000473:pathology; D005757:Gastritis, Atrophic / Q000145:classification* / Q000473:pathology*; D006801:Humans; D015588:Observer Variation; D011706:Pyloric Antrum / Q000473:pathology; D015203:Reproducibility of Results; D012720:Severity of Illness Index