Reviewer ’s report  
 
Title: Cross Design Analysis of Randomized and Observational Data - Application to 
Continuation Rates for a Contraceptive Intra Uterine Device Containing Levonorgestrel in 
Adolescents and Adults  
 
Version: 0 Date: 29 Aug 2018  
 
Reviewer: Reviewer 2  
 
Reviewer's report:  
 
PEER REVIEWER COMMENTS: To view the full report from the academic peer reviewer, 
please see the attached file.  
 
REVIEWER COMMENTS FROM REPORT: I reviewed the manuscript "Cross Design Analysis 
of Randomized and Observational Data - Application to Continuation Rates for a Contraceptive 
Intra Uterine Device in Adolescents and Adults".  
 
The study design is appropriate and combines the strong points of both randomized controlled 
trials (more focused on internal validity) and observational studies (more focused on external 
validity). From a methodological point of view, I do not have particular concerns: th e data 
analysis was accurately performed and the conclusion is consistent with it. The references are 
appropriate, and the English style and grammar are adequate. The limitations of the study are 
fairly highlighted and discussed. Although this work will no t produce a paradigm shift in current 
clinical practice, in my honest opinion it could be considered as an interesting additional piece of 
evidence to the topic.  
 
REQUESTED REVISIONS:  
In general, the manuscript may be improved by carrying out the followin g minor revisions:  
- Abstract (Page 2): the ClinicalTrials.gov identifier NCT00185380 refers only to the RCT 
and does not identify the analysis of this paper, which is obtained by a data combination 
of that RCT and an observational study (from the Contrace ptive CHOICE Project). I 
would delete it.  
- Competing interests, page 11: as fairly reported, all the authors of this manuscript are 
employees of Bayer. In addition, also the RCT from which data were extrapolated 
(NCT00185380) was sponsored by Bayer. Consi dering that this study is about Mirena®, 
a Bayer product, this may raise some concerns from the ethical point of view. In any 
case, I leave this evaluation to the Editor who is handling the manuscript.  
ADDITIONAL REQUESTS/SUGGESTIONS:  
All the suggestions/ recommendations are reported in section 5→1 (Research Quality Review 
Commentary)  
 
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 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.  
 
Not relevant to this manuscript  
 
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 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 com peting 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.  
 
This reviewer has been recruited by a partner organization, Research Square. Revie wers with 
declared or apparent competing interests are not utilized for these reviews. This reviewer has 
agreed to publication of their comments online under a Creative Commons Attribution License 
attributed to Research Square and was paid a small honorari um for completing the review within 
a specified timeframe. Honoraria for reviews such as this are paid regardless of the reviewer 
recommendation.  
 
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 website 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