Implementation of a biopsy protocol to improve detection of esophageal eosinophilia: a Danish registry-based study

BACKGROUND : In the North Denmark Region (580 272 inhabitants), only 0-4 cases of possible eosinophilic esophagitis (EoE) were identified annually in 1999-2010, suggesting underdiagnosis. This study aimed to increase the diagnosis of EoE by introducing a regional biopsy protocol for patients with dysphagia. METHODS : In 2011, leaders of regional endoscopy units attended a consensus meeting where a biopsy protocol was proposed. The national pathology registry was used to identify patients with esophageal eosinophilic inflammation during 2007-2017. RESULTS : Discussion resulted in consensus on a protocol to take eight biopsy samples in dysphagia patients (four biopsies from 4 cm and 14 cm above the esophagogastric junction-"4-14-4 rule") regardless of the macroscopic appearance, and to code eosinophilia systematically in the pathology registry. A pictogram showing the 4-14-4 rule was sent to all endoscopy units. The number of patients with esophageal eosinophilia detected per year increased 50-fold after the protocol was implemented in 2011 (median of 1 [interquartile range 0-3] vs. 52 [47-56]; P < 0.001), and the number of biopsy samples per patient doubled (median 4 [4-5] vs. 8 [6-9]; P < 0.04). Of 309 patients diagnosed with esophageal eosinophilia in 2007-2017, 24 % had erosive esophagitis or Barrett's esophagus, and 74 % had EoE. CONCLUSIONS : A consensus-based biopsy protocol and improved coding of eosinophilia in the pathology registry resulted in a 50-fold increase in patients diagnosed with esophageal eosinophilia/year. These patients can now receive treatment. The effort to establish the protocol and change the culture of endoscopists and pathologists was minimal.