Comparison of Adenoma Detection Miss Rates at Colonoscopy Associated With Different Withdrawal Times

Study Overview
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Brief Summary
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The objective of this study is to determine the optimal withdrawal time for colonoscopy. A 6-minute withdrawal time is currently the standard of care but has only been evaluated in an observational fashion. The investigators believe that this should be validated in a standardized fashion. If the benefits of a 6 minute withdrawal are proven in this study (ie a low polyp/adenoma miss rate and a high polyp/adenoma detection rate), then this will support widespread adoption of a 6 minute withdrawal as the standard of care. This in turn may decrease the occurence of 'interval colon cancers', which are early colon cancers arising in subjects despite their having undergone colonoscopy. Our hypothesis is that the polyp/adenoma detection rate will be unacceptably low and the polyp/adenoma miss rate will be unacceptably high in the 3-minute withdrawal group when compared to the 6-minute withdrawal group.

Detailed Description
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Eligible patients will be randomized to colonoscopy with either a 6-minute withdrawal time or a 3-minute withdrawal time. Patients will then undergo colonoscopy. All colonoscopies will be performed by a GI attending (standard of care). The colonoscopy is typically performed under conscious sedation using medications such as fentanyl and midazolam for comfort (standard of care). Occasional patients undergo colonoscopy under general anesthesia. For all patients, advancement of the colonoscope to the cecum will be followed by segmental withdrawal of the colonoscope in each of 3 segments of the examined colon (right side of colon, transverse colon and left side of colon). Following examination of each individual segment, the colonoscope will be readvanced to the proximal end of the segment and a 2 minute withdrawal will be re-performed. For those randomized to the 6-minute withdrawal each segment will be examined over 2 minutes, followed by a second look over each segment over 2 minutes by the same endoscopist. For those randomized to the 3-minute withdrawal time, advancement to the cecum will also be followed by segmental withdrawal in each of 3 segments of the examined colon. Each segment will be examined over 1 minute, followed by a second look over each segment over 2 minutes by the same endoscopist. All patients will therefore undergo a second look colonoscopy with a 6-minute withdrawal time ('de-facto' standard of care). Polyp/adenoma detection and miss rates will then be calculated and compared between the two groups.

Official Title
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Comparison of Adenoma Detection and Miss Rates at Colonoscopy Associated With a Six-minute Withdrawal Time vs a Three-minute Withdrawal Time

Conditions
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Adenoma, Adenoma and/or Adenocarcinoma

Intervention / Treatment
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* Procedure: 3-minute withdrawal time
* Procedure: 6-minute withdrawal time


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age > 18 Already scheduled for colonoscopy Exclusion Criteria: Age < 18 Pregnant women Mentally disabled Decisionally challenged Cancer subjects Healthy volunteers Prisoners

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: 3-minute withdrawal time<br>For subjects randomized to the 3-minute withdrawal time, advancement to the cecum will be followed by segmental withdrawal in each of 3 segments of the examined colon. Each segment will be examined over 1 minute, followed by a second look over each segment over 2 minutes by the same endoscopist. | Procedure: 3-minute withdrawal time<br>* For subjects randomized to the 3-minute withdrawal time, advancement to the cecum will be followed by segmental withdrawal in each of 3 segments of the examined colon. Each segment will be examined over 1 minute, followed by a second look over each segment over 2 minutes by the same endoscopist.<br>|
| Active Comparator: 6-minute withdrawal time<br>For subjects randomized to the 6-minute withdrawal, advancement to the cecum will be followed by segmental withdrawal in each of 3 segments of the examined colon. Each segment will be examined over 2 minutes, followed by a second look over each segment over 2 minutes by the same endoscopist. | Procedure: 6-minute withdrawal time<br>* For subjects randomized to the 6-minute withdrawal, advancement to the cecum will be followed by segmental withdrawal in each of 3 segments of the examined colon. Each segment will be examined over 2 minutes, followed by a second look over each segment over 2 minutes by the same endoscopist.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Polyp/Adenoma Detection Rate | Polyp/adenoma detection rate will be calculated for each segment of the tandem colonoscopy- this will be calculated as the number of polyps/adenomas that are discovered and resected for each segment of the tandem colonoscopy. | This will be calculated up to one week after data collection. | 
| Polyp/adenoma Miss Rate | Polyp/adenoma miss rate will be calculated for each segment of the tandem colonoscopy- this will be calculated as the number of polyps/adenomas that are discovered and resected on the tandem portion of each segment of the colonoscopy, divided by the total number of polyps/adenomas that are discovered/resected. | Polyp/adenoma miss rate will be calculated up to one week after data collection. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Polyp/adenoma detection rate, Polyp/adenoma miss rate, Colonoscopy withdrawal time