Withdrawal time as a quality indicator for colonoscopy – a nationwide analysis

Background and study aims: A withdrawal time of at least 6 min has been recommended as a quality indicator for colonoscopy. One drawback of many of the studies that have investigated withdrawal time and produced conflicting results has been their single-center design involving few endoscopists. Therefore, the validity of withdrawal time as a quality measure remains unclear. This study explores the value of individual withdrawal time in a nationwide analysis.

Patients and methods: This prospective cohort study comprised data from outpatient colonoscopies performed at 19 Norwegian centers from January to September 2009 and registered in the Norwegian Gastronet Quality Assurance (QA) program. The participating endoscopists were characterized by their median withdrawal time for visual colonoscopies (diagnostic colonoscopies without biopsy or therapy) and categorized into two visual withdrawal time (VWT) groups (< 6 min or ≥ 6 min) to analyze the predictive value of VWT for detection of one or more polyps ≥ 5 mm in diameter using multiple logistic regression models.

Results: The study included 4429 consecutive colonoscopies performed by 67 endoscopists. The adjusted odds ratio for the detection of polyps ≥ 5 mm was 1.21 (95 %CI 0.94 – 1.56, P = 0.14) for endoscopists with a median VWT ≥ 6 min compared with endoscopists with a median VWT < 6 min.

Conclusion: Withdrawal time using 6 min as the threshold is not a strong predictor of the likelihood of finding a polyp during colonoscopy and should not be used as a quality indicator.

• References

• 1 Seeff LC, Richards TB, Shapiro JA et al. How many endoscopies are performed for colorectal cancer screening? Results from CDC's survey of endoscopic capacity. Gastroenterology 2004; 127: 1670-1677
• 2 Kaminski MF, Regula J, Kraszewska E et al. Quality indicators for colonoscopy and the risk of interval cancer. N Engl J Med 2010; 362: 1795-1803
• 3 Lieberman D. A call to action – measuring the quality of colonoscopy. N Engl J Med 2006; 355: 2588-2589
• 4 Rex DK, Petrini JL, Baron TH et al. Quality indicators for colonoscopy. Am J Gastroenterol 2006; 101: 873-885
• 5 Barclay RL, Vicari JJ, Doughty AS et al. Colonoscopic withdrawal times and adenoma detection during screening colonoscopy. N Engl J Med 2006; 355: 2533-2541
• 6 Barclay RL, Vicari JJ, Greenlaw RL. Effect of a time-dependent colonoscopic withdrawal protocol on adenoma detection during screening colonoscopy. Clin Gastroenterol Hepatol 2008; 6: 1091-1098
• 7 Harris JK, Froehlich F, Wietlisbach V et al. Factors associated with the technical performance of colonoscopy: An EPAGE Study. Dig Liver Dis 2007; 39: 678-689
• 8 Taber A, Romagnuolo J. Effect of simply recording colonoscopy withdrawal time on polyp and adenoma detection rates. Gastrointest Endosc 2010; 71: 782-786
• 9 Gellad ZF, Weiss DG, Ahnen DJ et al. Colonoscopy withdrawal time and risk of neoplasia at 5 years: Results from VA Cooperative Studies Program 380. Am J Gastroenterol 2010; 105: 1746-1752
• 10 Hoff G, Bretthauer M, Huppertz-Hauss G et al. The Norwegian Gastronet project: Continuous quality improvement of colonoscopy in 14 Norwegian centres. Scand J Gastroenterol 2006; 41: 481-487
• 11 Eide TJ, Stalsberg H. Polyps of the large intestine in Northern Norway. Cancer 1978; 42: 2839-2848
• 12 Hoff G, Foerster A, Vatn MH et al. Epidemiology of polyps in the rectum and sigmoid colon. Histological examination of resected polyps. Scand J Gastroenterol 1985; 20: 677-683
• 13 Gondal G, Grotmol T, Hofstad B et al. The Norwegian Colorectal Cancer Prevention (NORCCAP) screening study: baseline findings and implementations for clinical work-up in age groups 50–64 years. Scand J Gastroenterol 2003; 38: 635-642
• 14 Millan MS, Gross P, Manilich E et al. Adenoma detection rate: the real indicator of quality in colonoscopy. Dis Colon Rectum 2008; 51: 1217-1220
• 15 Simmons DT, Harewood GC, Baron TH et al. Impact of endoscopist withdrawal speed on polyp yield: implications for optimal colonoscopy withdrawal time. Aliment Pharmacol Ther 2006; 24: 965-971
• 16 Overholt BF, Brooks-Belli L, Grace M et al. Withdrawal times and associated factors in colonoscopy: a quality assurance multicenter assessment. J Clin Gastroenterol 2010; 44: e80-e86
• 17 Sawhney MS, Cury MS, Neeman N et al. Effect of institution-wide policy of colonoscopy withdrawal time > or = 7 minutes on polyp detection. Gastroenterology 2008; 135: 1892-1898
• 18 Baxter NN, Sutradhar R, Forbes SS et al. Analysis of administrative data finds endoscopist quality measures associated with postcolonoscopy colorectal cancer. Gastroenterology 2011; 140: 65-72
• 19 Seip B, Bretthauer M, Dahler S et al. Sustaining the vitality of colonoscopy quality improvement programmes over time. Experience from the Norwegian Gastronet programme. Scand J Gastroenterol 2010; 45: 362-369
• 20 Sonnenberg A. Inflationary caution in GI endoscopy. Gastrointest Endosc 2010; 71: 789-791