Interobserver variability in application of the revised Sydney classification for gastritis

The Sydney classification for gastritis provides guidelines for histologica l grading of gastric biopsies. In an ongoing study of gastric preneoplastic lesions in Chiapas, Mexico, 7 biopsies from 150 patients (4 from the antru m and 3 from the body) were obtained during endoscopy and studied histologi cally. The first 74 endoscopy specimens were read independently by 2 genera l surgical pathologists. We assessed diagnostic concordance using kappa sta tistics. The 2 pathologists then jointly reviewed biopsies about which they had disagreed to reach a final diagnosis. A second group of 76 endoscopies was subsequently evaluated independently by the 2 pathologists, and concor dance was again assessed. In the first group of biopsies, we found low conc ordance rates (Heliobacter pylori 0.59, acute inflammation 0.22, intestinal metaplasia 0.60, and atrophy 0.04). In the second group, of independently reviewed cases, there was better concordance (H pylori 0.77, acute inflamma tion 0.50, intestinal metaplasia 0.70, and atrophy 0.64). We presumed that use of the Sydney classification would result in minimal interpretational d ifferences achieving ideal kappas greater than 0.80. Because pathology resu lts are based on subjective interpretation of this classification, complete diagnostic agreement is practically impossible. Concordance by general sur gical pathologists after joint review of cases was similar to that obtained by gastrointestinal pathologists. This is a US government work. There are no restrictions on its use.