Review for 10.1186/s12876-016-0476-6 (2016)

Reviewer ’s report  
 
Title: A randomized controlled trial of an educational video to improve quality o f bowel 
preparation for colonoscopy  
 
 
Version: 0 Date: 17 Sep 2015  
 
 
Reviewer: Senador  Moran Sanchez  
 
 
Reviewer's report:  
 
In the paper is not described how many people were excluded from the enrolment.In the 
discusion is admitted a selection bias but not defining the number of patients  rejected we cannot 
have a proper idea of the magnitude of this selection bias .Other papers shows no difference 
between groups in their results and a cause for this could be the selection procces,not excluding 
patients with low culture level  
 
 
In the method area, there is no reference to a correlation prior study to asess the ability of the 
endoscospist to grade colonoscopy cleaning level, just comment on their skill with the number of 
procedures performed.In this aspect it would be desirable to have a complete recording of  each  
procedure in order to asses the correlation between obs ervers. If it is not done has to be 
commented in the discusion  
 
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
Yes 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
No 
 
Are the conclusions drawn adequately supported  by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
Are you able to assess any statistics in the manuscript or would you recommend an  
additional statistical review?  
If an additional statistical review is recommended, please spec ify what aspects require further  
assessment in your comments to the editors.  
 
I recommend additional statistical review  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
Declaration of competing interests  
Please complete  a declaration of competing interests, considering the following questions:  
 
1. Have you in the past five years received reimbursements, fees, funding, or salary from 
an organisation that may in any way gain or lose financially from the publication of this  
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation that may in any way gain or lose  
financially from the publication of this manuscript, either now or in the future?  
 
3. Do you hold or are you currently applying for any patents relating to the content of the  
manuscript?  
 
4. Have you received reimbursements, fees, funding, or salary from an organization that 
holds  or has applied for patents relating to the content of the manuscript?  
 
5. Do you have any other financial competing interests?  
 
6. Do you have any non -financial competing interests in relation to this paper?  
 
If you can answer no to all of the above, write 'I declare that I have no competing interests' 
below.  If you r reply is yes to any, please give details below.  
 
I declare that I have no competing interes ts 
 
I agree to the open peer review policy of the journal. I understand that my name will be included  
on my report to the authors and, if the manuscript is accepted for publication, my n amed report  
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to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal