[Concordance between pathologists in the diagnosis of gastric atrophy according with the OLGA system]

The intestinal gastric cancer is preceded by a sequence of pathological changes whose link is mucosal atrophy. The modified Sydney system for atrophy is a parameter not reproducible among pathologists.

To know the interobserver variability using the OLGA system (Operative Link on Gastritis Assessment).

We selected 116 histologic slides. Sixty cases of both types of atrophy and 56 without atrophy were included. Three general pathologists, interested in gastrointestinal biopsies independently review the slides and established a diagnosis. For statistical analyses we employed singles frequencies in order to describe the individual diagnosis and the kappa test for evaluate the concordance between 2 and 4 observers with 2 and 3 categories.

The global concordance has a kappa index of 0.48 (IC 95% 0.4-0.57). When we compared two pathologists the kappa index varies from 0.82(IC 95% 0.73-0.91) to 0.36 (IC 95% 0.22-0.5). The consensus among three pathologists was achieved in 25 out 30 slides in the metaplastic variety and 11 out 30 for the non-metaplastic type. The concordance for the atrophy scale has a kappa index between 0.2 and 0.5.

The problematic atrophic evaluation with the Sydney system justify every effort to improve the interobserver evaluation. The OLGA system seems reproducible, although laborious,it requires a careful application, but with daily practice it could be applied easier. The clinician acceptation becomes crucial.