Background: Adenoma detection rate (ADR) at endoscopy has been used as a key performance indicator and is inversely associated with an interval diagnosis of colorectal cancer. As most endoscopy reporting systems do not incorporate pathology results, polyp detection rate (PDR) has been adopted by the British Society of Gastroenterology as a surrogate marker for ADR. The study aims to investigate the validity of using PDR as an acceptable surrogate marker for ADR at colonoscopy.
Methods: A prospectively maintained database of colonoscopies performed between July 2015 and July 2016 at our institution was analysed to assess PDR. This was cross referenced with a prospectively maintained histology database of endoscopically removed adenomata during the same period. Statistical analysis was performed using IBM SPSS, version 24. Inferential procedures employed included the Pearson’s correlation coefficient (r) and Binomial logistic regression.
Results: A total of 2,964 procedures were included for analysis with 789 polyps sent for histological assessment. The ADR of 0.19 (95% CI, 0.18–0.20) and PDR of 0.27 (95% CI, 0.25–0.28) significantly correlated (r=0.921, 95% CI, 0.55–0.99, P=0.003). Patient variables significantly associated with higher ADR included male gender OR =2.90 (95% CI, 2.25–3.74), longer withdrawal time OR =1.27 (95% CI, 1.23–1.32) as well as increasing age, length of procedure and experience of endoscopist.
Conclusions: PDR is a valid surrogate marker for ADR and may be used as a key performance indicator at endoscopy.
