The rising incidence of eosinophilic oesophagitis is associated with increasing biopsy rates: a population-based study

Background Eosinophilic oesophagitis (EoE) has evolved from a supposedly rare entity to one whose incidence rates are approaching that of inflammatory bowel disease. The factors responsible for this apparent increase in the incidence remain obscure. Aim To assess various endoscopist and pathologist factors that might affect the frequency of EoE being detected in a well-defined North American population. Hypothesis Increased endoscopist and pathologist awareness has contributed to the increased clinical recognition of EoE. Methods Cases of EoE were identified systematically using population-based pathology and endoscopy databases from January 2004 to December 2008 in Calgary, Canada (population 1.25million). EoE frequency was estimated with time trend analysis. Characteristics of individual endoscopists (n=45) were compared with diagnostic rates. Results Crude population incidence of EoE increased from 2.1 per 105 in 2004 to 11.0 per 105 in 2008: an annual increase of 39% (P<0.0001). The frequency in men was 4.5 times higher than in women (95% CI: 3.515.76). In patients presenting with dysphagia oesophageal biopsy rates increased from 17.0% in 2004 to 41.3% of EGDs in 2008: an annual rise of 26% (P<0.0001). On multivariate regression analysis, those endoscopists with higher biopsy rates were more likely to make the diagnosis of EoE (P=0.008). To include or exclude the diagnosis, typical histological features of EoE were reported more often by pathologists in 2008 as compared to 2004 (P=0.01 & P<0.0001 respectively). Conclusions The incidence of eosinophilic oesophagitis continues to rise in the general population, in part due to increasing oesophageal biopsy rates and a more detailed histological evaluation of specimens. The biopsy rate of an endoscopist is an indicator for a higher diagnostic yield.