Interlaboratory variability in the grading of XXXX in a nationwide cohort of @entity2513 .

@entity1 @entity189 @entity1893 @entity652 @entity1141 @entity2513
AIMS: Although @entity1893 ( @entity1893 ) is a risk factor for malignant transformation and future development of @entity652 / @entity189 , grade is not incorporated in the Dutch guidelines for colonoscopy surveillance, partly due to presumed interobserver variability. In a nationwide cohort of @entity2513 , we analysed the interlaboratory variability in the grading of @entity1141 in daily practice. METHODS AND RESULTS: Using the Dutch Pathology Registry (PALGA), all synoptically reported classic @entity652 in The Netherlands in 2013 were identified. Proportion of @entity652 with @entity1893 was determined for biopsies and polypectomies and compared between 37 laboratories by multivariable logistic regression analyses. In total, 21,030 colonoscopies of 20,270 @entity1 were included. @entity1893 was reported in 530 (3.6%) out of 14,866 @entity652 diagnosed on biopsies (range between laboratories: 0%-13.6%) and in 983 (11.8%) out of 8,346 @entity652 diagnosed on polypectomies (range 3.1%-42.9%). After adjustment for case mix, thirteen (35%) laboratories reported a significantly lower or higher frequency of @entity1893 than average. CONCLUSIONS: We observed considerable interlaboratory variation in the grading of @entity1141 in @entity2513 , which could only be partly explained by differences in case mix. Therefore, better standardization of grading criteria is needed before grade of @entity1141 can usefully be incorporated in colonoscopy surveillance guidelines. This article is protected by copyright. All rights reserved.
