Endoscopy 2016; 48(03): 256-262
DOI: 10.1055/s-0035-1569674
Original article
© Georg Thieme Verlag KG Stuttgart · New York

Monitoring colonoscopy withdrawal time significantly improves the adenoma detection rate and the performance of endoscopists

Stephan R. Vavricka*
1   Division of Gastroenterology and Hepatology, Triemlispital, Zurich, Switzerland
2   Division of Gastroenterology and Hepatology, University Hospital Zurich, Switzerland
,
Michael C. Sulz*
2   Division of Gastroenterology and Hepatology, University Hospital Zurich, Switzerland
,
Lukas Degen
3   Division of Gastroenterology and Hepatology, University Hospital Basel, Switzerland
,
Roman Rechner
2   Division of Gastroenterology and Hepatology, University Hospital Zurich, Switzerland
,
Michael Manz
4   Division of Gastroenterology and Hepatology, Claraspital, Basel, Switzerland
,
Luc Biedermann
2   Division of Gastroenterology and Hepatology, University Hospital Zurich, Switzerland
,
Christoph Beglinger
3   Division of Gastroenterology and Hepatology, University Hospital Basel, Switzerland
,
Shajan Peter
3   Division of Gastroenterology and Hepatology, University Hospital Basel, Switzerland
,
Ekaterina Safroneeva
5   Institute of Social and Preventive Medicine, University of Bern, Switzerland
,
Gerhard Rogler
2   Division of Gastroenterology and Hepatology, University Hospital Zurich, Switzerland
,
Alain M. Schoepfer
6   Division of Gastroenterology and Hepatology, Centre Hospitaler Universitaire Vaudois/CHUV, Lausanne, Switzerland
› Author Affiliations
Further Information

Publication History

Submitted: 02 April 2015

Accepted after revision: 09 October 2015

Publication Date:
25 January 2016 (online)

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Background and study aims: The recommended minimum withdrawal time for screening colonoscopy is 6 minutes. Adenoma detection rates (ADRs) increase with longer withdrawal times. We aimed to compare withdrawal times and ADRs of endoscopists unaware of being monitored vs. aware.

Patients and methods: Seven experienced gastroenterologists prospectively performed 558 screening colonoscopies during a 9-month period in a Swiss University hospital. Colonoscopy withdrawal times were first measured without the gastroenterologists’ knowledge of being monitored (n = 355 colonoscopies) and then with their knowledge (n = 203 colonoscopies).

Results: The median withdrawal time when gastroenterologists were unaware of being monitored was 4.5 minutes (interquartile range [IQR] 4 – 5.5 minutes) without intervention and 6 minutes (IQR 4 – 9 minutes) with intervention, increasing significantly to 7.3 minutes (IQR 6.5 – 9 minutes) and 8 minutes (IQR 7 – 11 minutes), respectively, when they were aware of being monitored (P < 0.001 both for colonoscopies with and without intervention). The ADR increased from 21.4 % when the gastroenterologists were unaware of being monitored to 36.0 % when they were aware (P < 0.001). In the multivariate regression model, the endoscopists knowing they were being monitored was the strongest factor associated with ADR (odds ratio 4.417; 95 % confidence interval [CI] 2.241 – 8.705; P < 0.001).

Conclusions: Colonoscopy withdrawal time in unmonitored gastroenterologists is shorter than recommended and increases with awareness of monitoring. ADR significantly increases when gastroenterologists are aware of being monitored. Implementation of systematic monitoring, and analysis of withdrawal time and ADR for each endoscopist may help to increase the ADR.

* The first two authors contributed equally to this article.