Reviewer ’s report  
 
Title: Association between the use of free -of-charge intrauterine d evices and a h istory of 
induced abortion: A retrospective study  
 
Version: 1 Date: 24 Aug 2019  
 
Reviewer: Akin -Tunde Ademola Odukogbe  
 
Reviewer's report:  
 
1. Rather than 'a chosen contraceptive method' - line 26 and 'w ho were residents in a predefined 
area within a German federal state' - lines 29 and 30, why not IUD and residents in 
Mecklenburg -West Pomerania, an economically challenged community in Germany.  
Note: The exact location of the study is difficult to know.  
 
2. While acknowledging the benefit of provision of free IUDs, the authors did not mention 
anything about sustainability of such ventures. Yet, sustaining a practice requires much more 
effort than initiating it.  
 
Additional comments are in the article.  
 
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
Yes 
 
Does the work inclu de the necessary controls?  
If not, please specify which controls are required in your 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 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 quest ions:  
 
1. Have you in the past five years received reimbursements, 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 
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 inte rests 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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