Reviewer ’s report  
 
Title: Hormonal contraceptive use and prevalence of premenstrual symptoms in a multiethnic 
Canadian population  
 
Version: 1 Date: 29 Aug 2017  
 
Reviewer: Tizta Tilahun  
 
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, graphs, 
supporting materials or other aspects of your report which cannot be included in a text format.  
Thank you for considering an important issue on board, not much studied an d need attention. 
However I have some issues to be clear for the reader.  
 
In the cover letter abstract part:  
- Please remove abbreviations in the abstract part.  
- The conclusion does not give a good picture of which ethnic group has shown more 
associatio n the dependent variable.  
 
In the methods section  
- It is not specific that whether men or women are taken for the analysis, make it clear in the 
document.  
- The ethnic groups are too many to compare, but at least take only the major ones. However, 
the pe rcent of others as a group accounts 34%, how do you consider it in the logistic 
regression? and its explanation.  
- Did you compute regression for all the ethnic groups at a time? what was the result?  
Please overwrite this text when adding your comments to  the authors.  
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 autho rs. 
 
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 add itional statistical review is recommended, please specify what aspects require further  
assessment in your comments to the editors.  
 
Not relevant to this manuscript  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
Declaration of competing interests  
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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 f or 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 competing interests.  
 
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