Reviewer ’s report  
 
Title:  Factors associated with deep infiltrating endometriosis versus ovarian endometrioma in 
China: A subgroup analysis from the FEELING study  
 
Version: 1 Date: 09 Apr 2018 
 
Reviewer:  Paul Yong  
 
Reviewer’s report:  
 
This study is a subanalysis of the FEELING study, comparing 156 women with OMA vs. 78 
women with DIE (+/ - OMA) in China.  The authors found OMA to be associated with stress and 
organic food consumption (relative to DIE group); while DIE was associated with having 
siblings, GI symptoms during menstruation, and fruit/veg etable consumption (relative to OMA 
group).  
 
The manuscript is clear and easy to read.  The authors are appropriately cautious in their 
interpretation of the findings.  They note the conflicting literature, and also emphasize that 
further prospective and l arger studies are needed.   
 
The authors directly compared DIE vs. OMA; it would have been interesting to also compare to 
the superficial endometriosis group (SUP) from China that the authors mention in the Methods, 
e.g. DIE vs. SUP and OMA vs. SUP.  Perha ps this could be pursued in future work.  
 
I do have one inquiry: The authors note that "Patients with concomitant DIE and OMA were 
included into the DIE group".  What # of DIE patients also had an OMA?  This is important to 
aid in the reader understanding the DIE vs. OMA comparison.  
 
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 you r comments to the authors.  
 
Yes 
 
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 specify 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 qual ity 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 t hat I have no competing interests' 
below. If your reply is yes to any, please give details below.  
 
I am doing research in DIE as well.  
 
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 named report 
including any attachments I upload will be posted on the websi te along with the authors' 
responses. I agree for my report to be made available under an Open Access Creative Commons 
CC-BY license ( http://creativecommons.org/licenses/by/4.0/ ). I understand that any comments 
which I do not wish to be included in my named report can be included as confidential comments 
to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal