Review for 10.1186/s12876-018-0814-y (2018)

Reviewer ’s report  
Title: Obesity i ncreases the risk of erosive esophagitis but metaboli c unhealthiness alone does 
not: a large -scale cross -sectional study  
 
Version: 0 Date: 17 Mar 2018  
 
Reviewer: Paola Iovino  
 
Reviewer's report:  
The aim of this study was to investigate the relationship between  endoscopically proven erosive 
esophagitis, obesity, and metabolic health status in a population screened at the Center for Health 
Promotion of Seoul St. Mary's Hospital (Seochogu, Seoul, South Korea).  
 
General comment:  
Although this is a nice study and t here are not a plethora of studies on this topic, drawbacks such 
as the retrospective data collection and the cross -sectional design should not be overcome. 
Consequently, I suggest to modify the conclusion that  
metabolic unhealthiness may not be involved in EE pathogenesis as observational studies cannot 
prove causality since residual confounding by unmeasured variable can never be completely 
ruled out.  
 
Specific comments:  
1. Could you explain the criteria to participate to the health -screening program?  
Which is the representing percentage of the entire adult population?  
 
2) Why did you exclude subjects who underwent multiple upper gastrointestinal endoscopies 
during the study period? Why do you not maintain the first one?  
 
Given the explorative nature observational research as well as the well -known risk of several 
bias that cannot be efficiently handled by this design (such studies are powered to detect small 
differences in the endpoint of interest and to allow for extensiv e adjustment for confounding, to 
perform subgroup analyses and to evaluate the contribution of several independent variables to 
the variance in the outcome distribution) I recommend additional statistical review to increase 
the appealing of the study.  
 
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
No 
Does the work include the necessary controls?  
If not, ple ase specify which controls are required in your comments to the authors.  
Unable to assess  
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
No 
Are you able to assess any statistics in the manuscri pt or would you recommend an 
additional statistical review?  
If an additional statistical review is recommended, please speci fy what aspects require further 
assessment in your comments to the editors.  
I recommend additional statistical review  
Quality of written En glish  
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 reimbursem ents, f ees, 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 
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3. Do you hold or are you currently applying for any patents  relating to the content of th e 
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 your reply is yes to any, please give details below.  
 
I declare that I have no co mpeting interests  
 
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