Relationship between the endoscopic withdrawal time and adenoma/polyp detection rate in individual colonic segments: a KASID multicenter study

Background and Aims: Appropriate colonoscopy withdrawal times for individual colonic segments are not well known. The relationship between withdrawal time and adenoma detection rate (ADR)/polyp detection rate (PDR) in individual colonic segments was examined in this study. Methods: This was a prospective observational study involving 724 patients who underwent colonoscopy screening or surveillance colonoscopy from October 2015 to February 2017 at 10 university hospitals. Results: In the right side of the colon, the ADR (33.2% vs 13.7%, P <.001), PDR, serrated polyp detection rate, and number of adenomas per colonoscopy (APC) were significantly higher when the colonoscopy withdrawal time was ≥2 minutes compared with <2 minutes. When the withdrawal time was ≥4 minutes in the proximal colon and ≥3 minutes in the left segment of the colon, the ADR, PDR, and APC were significantly higher compared with withdrawal times of <4 minutes and <3 minutes, respectively. Multivariate analyses showed that the ADR was significantly associated with withdrawal times of ≥2 minutes in the right side of the colon (odds ratio [OR], 2.98; 95% confidence interval [CI], 1.72-5.15; P <.001), ≥4 minutes in the proximal colon (OR, 4.48; 95% CI, 3.15-6.36; P <.001), and ≥3 minutes in the left segment of the colon (OR, 2.92; 95% CI, 1.74-4.91; P <.001). Conclusions: The PDR and ADR appeared to be significantly increased when the withdrawal time was ≥2 minutes in the right-sided colon segment, ≥4 minutes in the proximal colon, and ≥3 minutes in the left-sided colon segment compared with shorter withdrawal times.