P53 Does polyp detection rate accurately reflect adenoma detection rate

Introduction Thorough mucosal examination at colonoscopy is essential to detect pathology and ensure high quality procedures. Adenoma detection rate (ADR), defined as the number of colonoscopies where at least one adenoma is detected, is the most important marker of colonic mucosal visualisation and therefore of colonoscopy quality. Histology results are required, making the use of ADR challenging. Polyp detection rate (PDR) is more readily available as it can be collected directly on endoscopy reporting systems. The use of PDR as a substitute for ADR has been deemed acceptable providing it accurately reflects ADR.1 We aim to investigate whether PDR can be reliably used as an alternative to ADR and therefore as a marker of colonoscopy quality. Methods Data were collected from independent endoscopists in eight hospitals in England over a six-month period, including; ADR, PDR, PDR excluding rectal hyperplastic polyps (RHP), mean patient age. The ADR:PDR ratio (APDRQ) per endoscopist and Pearson correlation between ADR and PDR were computed, including and excluding rectal hyperplastic polyps. Multiple linear regression analysis was used to develop a model to predict an endoscopist’s ADR from their PDR. Results 9265 colonoscopies performed by 118 endoscopists were included. Mean ADR and PDR per endoscopist were 17% (range 0–36.3, sd 7.37) and 27.2% (range 0–57.5, sd 9.3), respectively. The mean APDRQ was 0.60 (range 0–1.00, sd 0.21); this was 0.64 (range 0–1.17, sd 0.21) when RHPs were excluded. ADR and PDR were strongly correlated (rho=0.75, p Conclusions This study demonstrates that PDR can accurately be used as a marker of ADR as long as age is also considered. Reference Rees CJ, et al. UK key performance indicators and quality assurance standards for colonoscopy. Gut 2016;65:1923–9