Training Effect on the Inter-observer Agreement in Endoscopic Diagnosis and Grading of Atrophic Gastritis according to Level of Endoscopic Experience

BACKGROUND: Endoscopic diagnosis of atrophic gastritis can contribute to risk stratification and thereby tailored screening for gastric cancer. We aimed to evaluate the effect of training on inter-observer agreement in diagnosis and grading of endoscopic atrophic gastritis (EAG) according to the level of endoscopists' experience. METHODS: Twelve endoscopists (six less-experienced and six experienced) participated in this prospective study. The training session consisted of 1) four interventions with two-week intervals, and 2) a follow-up period (two follow-up assessments without feedback). EAG was categorized as C1 to O3 according to the Kimura-Takemoto classification. Kappa statistics were used to calculate inter-observer agreement. RESULTS: At baseline, kappa indexes were 0.18 in the less-experienced group and 0.32 in the experienced group, respectively. After four interventions with feedback, the kappa index improved in both groups and was sustained during the follow-up period. Overall diagnostic yields of EAG were 43.1% ± 10.7% in pre-intervention and 46.8% ± 5.9% in post-intervention. Variability in the rate of diagnosis of EAG significantly decreased in the less-experienced group (r = 0.04, P = 0.003). CONCLUSION: Irrespective of experience level, inter-observer agreement for diagnosis and grading of EAG improved after training and remained stable after intervention.