[Use of Los Angeles Classification in Erosive Esophagitis: analysis of inter-observer and intra-observer agreement].

Introduction: Gastroesophageal reflux disease is a com-mon condition with a prevalence of 10 to 20% in Western countries. The Los Angeles Classification is the standard endoscopic system for categorizing erosive esophagitis. Objectives: To evaluate intra- and inter-observer agreement among resident physicians and gastroenterology specialists in classifying the severity of reflux-related erosive esopha-gitis using the Los Angeles Classification. Materials and methods: A cross-sectional study was conducted with 59 participants (25 specialists and 34 residents) who clas-sified 40 endoscopic images according to the Los Angeles Classification (10 images were duplicated). Inter-observ-er agreement was analyzed using Fleiss's kappa index and intra-observer agreement using Cohen's kappa. Results: Inter-observer agreement was moderate among specialists (κ = 0.425, IC95% 0.39 - 0.46) and acceptable among residents (κ = 0.297, IC95% 0.26-0.33), and the dif-ference was statistically significant (p < 0.001). Over-all intra-observer agreement was moderate (κ = 0.525, IC95% 0.47 - 0.58). Conclusion: Low inter- and intra-observer agreement was observed when using the Los Angeles Classification for esophagitis, with signifi-cant differences when comparing groups with different levels of experience. The development and application of local clinical-endoscopic protocols is recommended to standardize diagnostic and therapeutic criteria, optimize resources, and contribute to the training of gastroenter-ology specialists.