Correlation Between Polyp and Adenoma Detection Rate in Trainee Endoscopists

Abstract

Introduction: The adenoma detection rate (ADR) is a widely accepted quality benchmark for screening colonoscopy, but calculation requires labor-intensive manual confirmation of histology. Previous studies have shown that the polyp detection rate (PDR) correlates well with ADR and may serve as a surrogate benchmark, although the ADR/PDR ratio may vary by colonic segment. In this study, we assessed the relationship between PDR and ADR in colonoscopies performed by trainees, for whom a surrogate benchmark may be a more practical method of tracking performance. Additionally, we evaluated the relationship between PDR and sessile serrated polyp (SSPDR) and advanced adenoma detection rates (AADR). Methods: We examined all outpatient colonoscopies performed by trainees at a VA facility from 8/16/16-12/29/17. We excluded incomplete procedures and those with Boston Bowel Preparation Scale scores less than 2 in any segment. Variables collected included patient demographics, year of fellowship, and endoscopic and histologic findings. Results: Table 1 shows patient characteristics, trainee status, and overall findings in 814 colonoscopies. Our population was predominantly (44%) black. The majority (88%) of procedures were performed for screening or surveillance, and most (47%) were performed by second-year fellows. The overall PDR, ADR, SSPDR, and AADR were 77%, 57%, 3%, and 17%. Table 2 shows the PDR, ADR, SSPDR, AADR, and the respective ratios overall as well as by colonic segment and year of training. The overall ADR/ PDR ratio was 0.74. The ratio was similar in the right (0.77) and transverse colon (0.75) but lower in the left colon (0.52). The same pattern was seen for the overall SSPDR/PDR and AADR/PDR ratios. When stratified by year of training, the overall ratios were consistent and a similar decline in ratios from the right to the left colon was observed in most cases. Notably, the AADR/PDR ratio in the right colon was substantially higher for third-year fellows, which suggests training may improve the efficiency of detecting advanced adenomas in the right colon. Conclusion: The overall ADR/PDR ratio in our study was higher than previously reported, which may reflect the predominantly male veteran population and the presence of a supervising physician. The overall ratios did not vary by year of training and but did decrease in the left colon. These results provide valuable preliminary data for how the PDR can be used to calculate the ADR, SSPDR, and AADR for trainee endoscopists.222_A Figure 1. Abbreviation: IQR, inter-quartile range a Advanced adenoma: any adenoma ≥10 mm in size, with villous component, or with high grade dysplasia OR any sessile serrated polyp ≥10 mm in size or with dysplasia222_B Figure 2. Abbreviations: ADR, adenoma detection rate; PDR, polyp detection rate; SSPDR, sessile serrated polyp detection rate; AADR, advanced adenoma detection rate.