CLINICAL—ALIMENTARY TRACT Effect of Institution-Wide Policy of Colonoscopy Withdrawal Time >7 Minutes on Polyp Detection MANDEEP S. SAWHNEY,* MARCELO S. CURY,* NAAMA NEEMAN, ‡ LONG H. NGO, ‡ JANET M. LEWIS,* RAM CHUTTANI,* DOUGLAS K. PLESKOW,* and MARK D. ARONSON ‡ Divisions of *Gastroenterology and ‡ General Internal Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts See editorial on page 1845. Background & Aims: Practice guidelines recommend that endoscopists spend at least 7 minutes examining the colonic mucosa during colonoscopy withdrawal to optimize polyp yield. The aim of this study was to determine if the implementation of an institution- wide policy of colonoscopy withdrawal time >7 min- utes was associated with an increase in colon polyp detection. Methods: All 42 endoscopists at our insti- tute were asked to attain a colonoscopy withdrawal time of at least 7 minutes. Compliance with 7-minute withdrawal time was recorded for all nontherapeutic colonoscopies. Polyp detection ratio (number of polyps detected divided by number of colonoscopies performed) was computed. Regression models were used to assess the association between compliance with 7-minute withdrawal time and polyp detection. Results: During the study period, 23,910 colonosco- pies were performed. The average age of patients was 56.8 years, and 54% were female. Colon cancer screen- ing or surveillance was the indication for 42.5% of colonoscopies. At the beginning of the study, the polyp detection ratio was 0.48. Compliance with 7-minute withdrawal time for nontherapeutic proce- dures increased from 65% at the beginning of the initiative to almost 100%. However, no increase in polyp detection ratio was noted over the same period for all polyps (slope, 0.0006; P  .45) or for polyps 1–5 mm (slope, 0.001; P  .26), 6 –9 mm (slope, 0.002; P  .43), or >10 mm (slope, 0.006; P  .13). No association was detected when only colonoscopies performed for screening or surveillance were ana- lyzed. Conclusions: An institution-wide policy of colonoscopy withdrawal time >7 minutes had no ef- fect on colon polyp detection. A pproximately 145,000 new cases of colorectal cancer occur every year in the United States, and one third of these are expected to result in death. 1,2 Several lines of evidence suggest that colon cancers arise from colon polyps and that it takes several years for a polyp to become a cancer. 2–7 This forms the basis for the current practice of serial colonoscopy at which all visible polyps are removed. The effectiveness of colonoscopy is depen- dent, among other factors, on the endoscopist removing all colon polyps before they become cancerous. Studies of tandem colonoscopy suggest that up to 27% of colon polyps may be missed during routine colonoscopy. 8,9 Strategies that improve polyp detection during colonos- copy are therefore an urgent priority. Two recent studies have shown that endoscopists who spend more time examining the colonic mucosa during colonoscopy withdrawal have a higher likelihood of find- ing colon polyps than their counterparts. 10,11 While these studies show an association between mean endoscopist withdrawal time and the number of polyps found during colonoscopy, it is not known if requiring all endoscopists to spend more time examining the colonic mucosa would improve colon polyp detection. We instituted a quality improvement initiative at our medical center that re- quired all endoscopists to spend at least 7 minutes ex- amining the colonic mucosa while withdrawing the colonoscope. The aim of our study was to determine if the implementation of an institution-wide policy of colonoscopy withdrawal time 7 minutes would be as- sociated with an increase in colon polyp detection. Patients and Methods In February 2006, the Gastroenterology Division at Beth Israel Deaconess Medical Center in Boston, Mas- sachusetts, started using colonoscopy withdrawal time as a marker of colonoscopy quality. Available literature on colonoscopy withdrawal time was reviewed and discussed at a staff meeting, and all endoscopists were asked to aim for a colonoscopy withdrawal time of at least 7 minutes. Colonoscopy withdrawal times for colonoscopies at Abbreviations used in this paper: CI, confidence interval. © 2008 by the AGA Institute 0016-5085/08/$34.00 doi:10.1053/j.gastro.2008.08.024 CLINICAL– ALIMENTARY TRACT GASTROENTEROLOGY 2008;135:1892–1898