Review for 10.1186/s12876-020-01257-4 (2020)

Reviewer ’s report  
 
Title: Narrow -Band Imaging and High -Definition White -Light Endoscopy in patients with 
Serrated Lesions not fulfilling criteria for Serrated Polyposis Sy ndrome: A randomized controlled  
trial with tandem colonoscopy  
 
Version: 0 Date: 18 Jul 2019  
 
Reviewer: Arnaud - Alvès  
 
Reviewer's report:  
 
Please include all comments for the authors in this box rather than uploading your report as an 
attachment. Please only upload as attachments annotated versions of manuscripts, gr aphs, 
supporting materials or other aspects of your report which cannot be included in a text format.  
 
Please overwrite this text when adding your comments to the authors.  
 
The present manuscript explored whether narrow -band imaging (NBI) compared with high -
definition white light endoscopy could improve the serrated detection rate. The authors conducted 
a randomized cross -over trial. To detect a difference with an 80% power and a significance level 
of 0;05, 81 polyps were required, leading to 41 patients. Thi s paper is well written and structured. 
However, there are some comments to make in this regard:  
 
1. We agree with the authors that patients were evaluated by the same endoscopist, with 
tandem ("back -to-back") colonoscopy. Thus the same endoscopist used th e two 
techniques consecutively. How did the authors explain that the endoscopist was blinded 
to the randomization list?  
 
2. The authors found that the use of NBI instead of HD -WLE was not superior in detecting 
polyps, including serrated lesions. A total of  246 suspected polyps with a median size of 
3 mm were detected in 41 patients. Why did the authors suggest that a larger study would 
probably not yield similar results? Did they mean that their hypothesis was understated?   
 
Are the methods a ppropriate 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.  
 
Yes 
 
Are the conclu sions 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 manus cript or would you recommend an additional 
statistical review?  
If an additional statistical re view is recommended, please speci fy what aspects require further 
assessment in your comments to the editors.  
 
I am able to assess the statistics  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Needs some language corrections before being published  
 
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 financial ly from the 
publication of this manuscript, either now or in the future?  
 
2.  Do you hold any stocks or shares in an organisation t hat 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 al l of the above, write 'I declare that I have  no competing interests' below. 
If your reply is yes to any, please give details below.  
 
i declare that i have no competing interests' below  
 
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