Effect of institution-wide policy of colonoscopy withdrawal time > or = 7 minutes on polyp detection

Gastroenterology. 2008 Dec;135(6):1892-8. doi: 10.1053/j.gastro.2008.08.024. Epub 2008 Aug 27.


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 > or = 7 minutes was associated with an increase in colon polyp detection.

Methods: All 42 endoscopists at our institute 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 colonoscopies were performed. The average age of patients was 56.8 years, and 54% were female. Colon cancer screening 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 procedures 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 > or = 10 mm (slope, 0.006; P = .13). No association was detected when only colonoscopies performed for screening or surveillance were analyzed.

Conclusions: An institution-wide policy of colonoscopy withdrawal time > or = 7 minutes had no effect on colon polyp detection.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Academic Medical Centers / statistics & numerical data*
  • Adult
  • Aged
  • Aged, 80 and over
  • Clinical Competence
  • Colonic Polyps / diagnosis*
  • Colonoscopy / methods*
  • Female
  • Humans
  • Male
  • Massachusetts
  • Middle Aged
  • Quality of Health Care
  • Retrospective Studies
  • Time Factors
  • Young Adult