In 2002, a U.S. Multi-Society Task Force on colorectal cancer recommended a 6-minute or more withdrawal time as an indicator of a quality colonoscopy. In 2006, Barclay, Vicari, Daughty, Johanson, and Greenlaw (2006) found a correlation between longer withdrawal time and an increased rate in the detection of adenomas. In January 2008, the endoscopy department at our institution adopted the Multi-Society Task Force recommendation. The aim of our study was to evaluate the effect of a minimal 6-minute withdrawal time policy at our institution on polyp detection rate. All colonoscopies performed for screening indications from April 2007 to September 2008 were reviewed retrospectively. Group I (pre-policy) was compared with Group II (post-policy). Data collected included age, gender, indication, polyp detection rate, size, and withdrawal time. Unpaired t tests evaluated pre- and postprocedure results. Fisher's exact tests were used to compare detection rates between withdrawal time less than 6 minutes and more than 6 minutes. Mann–Whitney U Tests were performed to analyze the significance between the number of polyps detected for withdrawal time less than 6 minutes versus more than 6 minutes. A total of 1,342 colonoscopies were available for analysis in Group I and 1,316 in Group II. Polyp detection rate was 46.6% in Group I versus 48.2% in Group II (p = .39), a non-statistically significant difference; however, there was a trend toward identifying small- and medium-sized polyps in Group II. Small polyps can carry a risk of severe dysplasia (Church, 2004). Data were then analyzed for withdrawal time. The polyp detection rate was 20.9 in procedures that took less than 6 minutes versus 48.3 in those that took more than 6 minutes (p ≤ .01). In this study, a 6-minute or more withdrawal time increased the polyp detection rate by 133% for all polyp sizes, especially small and medium. Small polyps (5 mm or less) should be removed and not ignored. A 6-minute or more withdrawal time should be mandatory in those patients without a previous colon resection.
Scott L. Baker, MD, FACS, is with Surgical Institute of South Dakota, Sioux Falls.
Roberta A. Miller, BSN, RN, CGRN, is Quality Specialist, Grant Medical Center, Columbus, Ohio.
Amy Creighton, MS, is Clinical Data Base Informatist, Grant Medical Center, Columbus, Ohio.
Pedro S. Aguilar, MD, FACS, FASCRS, is Program Director of the Colorectal Surgery fellowship program, Grant Medical Center, Columbus, Ohio.
Correspondence to: Roberta A. Miller, BSN, RN, CGRN, Grant Medical Center, 285 East State Street, Suite 540, Columbus, OH 43215 (B.Miller@OHIOHealth.com).
The authors have no conflicts of interest or financial ties to declare.
Received January 10, 2013
Accepted October 30, 2013