Withdrawal times and associated factors in colonoscopy: a quality assurance multicenter assessment

To evaluate the use and impact of the recommended withdrawal time of at least 6 minutes from the cecum in colonoscopy in multiple gastroenterology endoscopy ambulatory surgery centers serving a wide geographical area.

An observational prospective multicenter quality assurance review was conducted in 49 ambulatory surgery centers in 17 states with 315 gastroenterologists. There was no intervention with this quality assessment program as care of patients and the routine of gastroenterologists continued as standard practice. Multivariable analysis was applied to the database to examine factors affecting withdrawal time and polyp detection.

There were 15,955 consecutive qualified patients receiving colonoscopies in a designated 4-week period. Gastroenterologists with average withdrawal times of 6 minutes or more in patients with no polyps were 1.8 times more likely to detect 1 or more polyps and had a significantly higher rate (P<0.0001) of polyp detection in patients with findings of polyps compared to gastroenterologists with average withdrawal times of less than 6 minutes in patients with no polyps. For patients with no pathology, the mean time of withdrawal was 6.98 (SD=4.34) minutes and for patients with pathology mean time of withdrawal was 11.27 (SD=6.71) minutes. Strongest predictors of withdrawal time of 6 minutes or more were presence of carcinoma (3.7 times more likely than those with no pathology), adenoma (2.0 times more likely than those with no pathology), and number of polyps visualized (1.7 times more likely for each polyp).

This quality assurance assessment from standard colonoscopy practices of 315 gastroenterologists in 49 endoscopic ambulatory surgery centers serving a wide geographical area provides support for the merits of a colonoscopy withdrawal time from the cecum of 6 minutes or more to improve the detection of polyps.