Background/aims: The polyp detection rate (PDR) has been suggested as a surrogate for adenoma detection rate (ADR). The purpose of this study was to determine the level of agreement between PDR and ADR in the proximal and distal colon.
Methods: A total of 1,937 consecutive, asymptomatic individuals aged 40 years and older who underwent colonoscopies at six academic teaching hospitals in Korea were included in this study. PDR and ADR were calculated for each colonic segment. PDR was compared with ADR in the proximal and distal colon.
Results: During 1,937 colonoscopies, 1,862 polyps were removed; 1,421 (76%) were adenomas. The PDR and ADR in the proximal colon was 25.8% and 22.8%, respectively (kappa value=0.917, p=0.26), and that in the distal colon was 28.9% and 22.2%, respectively (p<0.001). There was a strong correlation between PDR and ADR in the proximal colon, but diverged in sigmoid colon and rectum.
Conclusions: PDR and ADR correlate well in the proximal colon, but not in the distal colon, especially sigmoid and rectum. PDR should be measured for each colonic segment when using PDR as a surrogate for ADR. PDR is a valid proxy for ADR in the proximal colon.