The Colon Endoscopic Bubble Scale (CEBuS); Validation Study

Study Overview
=================
Brief Summary
-----------------
Colonoscopy is currently accepted as the gold standard in screening, surveillance and prevention for colorectal cancer (CRC), and therefore, its quality is a major priority. The quality of colonoscopy is greatly dependent on the quality of the bowel preparation, which can be limited by stool, foam, bubbles and other debris. In fact, colonic bubbles are described in 30 to 40% of colonoscopies, possibly undermining the quality of the exam, impairing the endoscopists view, demanding the further use of water or simethicone and eventually increasing fatigue and costs, while diminishing diagnostic accuracy. Although previous attempts, to date no endoscopic scale is validated regarding the presence of bubbles and most widely accepted and already validated scales do not include the presence or absence of bubbles in their definition, leading to the use of different home-made scales in randomized trials and impairing any solid meta-analysis conclusion. As so, the goal of this study is to develop and validate a new colonic bubble score (Colon Endoscopic Bubble Scale - CEBuS).

Detailed Description
-----------------
Colonoscopy bowel preparation quality is a major concern since inadequate bowel preparation can reach levels as high as 30% which lead to several guidelines in this area, with the recent recommendation of at least 90% of good bowel preparations for all colonoscopies. In fact colonic mucosal visualization can be limited by residual stool, bubbles, bile and other debris increasing the risk of missing lesions. Around 30 to 40% of the exams can have bubbles increasing the risk of missing lesions and in the other hand increasing the time of the exam, generating more fatigue in the endoscopist and increasing the costs. The influence of colon bubbles in bowel preparation and strategies to solve them, for example with the use of simethicone in the bowel preparation, were addresses in recent studies, summarized in a 2018 meta-analysis recommending the use of simethicone in the bowel preparation scheme. Current recommendations advise the use of validated scales to evaluate bowel preparation quality, but the three major validated scales, Boston, Ottawa and Aronchick, does not address the problem of graduation of colonic bubbles and possible actions to undertake regarding the severity of the bubbles concentration. The advent of multiple randomized trials addressing the use of simethicone in the bowel preparation to reduce or eliminate bubble formation lead to attempts to design scales to graduate the concentration of bubbles in the colon. To date suggested scales are heterogeneous regarding the graduation (3 to 4 levels), defining criteria for each level with some based on percentage of colonic circumference obscured by bubbles to the amount of bubbles that could lead to miss a polyp of 5 or 10 millimetres.Two recently published studies on the influence of simethicone on bowel preparation tried to validate a colonic bubble scale, based on previous suggested and non-validated scales, although with only fair to moderate inter-observer variability. Therefore, the main goal of this project is to build and validate a comprehensive scale to graduate bubbles in the colon, assessing the inter- and intra-observer reliability of the scale. As a secondary objective, to determine the clinical attitude more frequent for each grade of the bubbles scale, among experts and residents. Aims: Build and validate a new colonic bubble score (Colon Endoscopic Bubble Scale - CEBuS).

Official Title
-----------------
The Colon Endoscopic Bubble Scale (CEBuS); Validation Study

Conditions
-----------------
Colon Polyp

Intervention / Treatment
-----------------
* Other: Validation of CEBuS


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: For the expert group: at least 15 years of regular practice in colonoscopy For the trainee group: 5 years or less in the practice of colonoscopy Exclusion Criteria: Non endoscopist and if out of the experience standards required.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Group 1 - experts<br>Evaluation of 15 images for each of the proposed 3 grade scale (45 images in total), randomly distributed to validate de scale; images will be assessed twice by the participants with a two-week interval in both study phases (the random distribution will vary between both evaluations). Together with the assessment of each image the participant is invited to choose one of possible three clinical actions (do nothing, wash with water and wash with simethicone) | Other: Validation of CEBuS<br>* Validation of a new score for bubbles in the colon.<br>|
| Group 2 - mix experts/trainee<br>If intra and interobserver rates in group 1 are >0.7 proceed to group 2 evaluation with the same intervention. Evaluation of 15 images for each of the proposed 3 grade scale (45 images in total), randomly distributed to validate de scale; images will be assessed twice by the participants with a two-week interval in both study phases (the random distribution will vary between both evaluations). Together with the assessment of each image the participant is invited to choose one of possible three clinical actions (do nothing, wash with water and wash with simethicone) | Other: Validation of CEBuS<br>* Validation of a new score for bubbles in the colon.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Reliability and reproducibility validation of the Colon Endoscopic Bubble Scale (CEBuS) | Evaluate the Intraclass correlation coefficients (ICC) and Fleiss kappa test The Colon Endoscopic Bubble Scale (CEBuS) was designed with a 3 grades scale: CEBuS-0 - no or minimal amount of bubbles, covering less than 5% of the surface, not relevant for adequate mucosa visibility (better outcome) CEBuS-1 - moderate amount of bubbles, covering between 5% and 50% of the surface, affecting mucosa visibility and requiring additional time for removal CEBuS-2 - severe amount of bubbles, covering more than 50% of the surface, obscuring mucosa visibility and requiring additional time for removal (worse outcome) | 1 month | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluation of the clinical attitude | Evaluated by the Intraclass correlation coefficients (ICC) and Fleiss kappa test | 1 month | 
| Influence of experience in the Colon Endoscopic Bubble Scale (CEBuS) | Evaluated by the Intraclass correlation coefficients (ICC) and Fleiss kappa test The Colon Endoscopic Bubble Scale (CEBuS) was designed with a 3 grades scale: CEBuS-0 - no or minimal amount of bubbles, covering less than 5% of the surface, not relevant for adequate mucosa visibility (better outcome) CEBuS-1 - moderate amount of bubbles, covering between 5% and 50% of the surface, affecting mucosa visibility and requiring additional time for removal CEBuS-2 - severe amount of bubbles, covering more than 50% of the surface, obscuring mucosa visibility and requiring additional time for removal (worse outcome) | 1 month | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Colonoscopy, Quality, Bowel, Preparation