Reviewer ’s report  
 
Title: Correlates of use of withdrawal for contraceptio n among women in Vietnam  
 
Version: 1 Date: 05 Mar 2020  
 
Reviewer: Summer L. Martins  
 
Reviewer's report:  
 
Thank you for the opportunity to review an updated draft of this manuscript. The authors have 
been generally responsive to the initial review and have provided a n improved manuscript. There 
are a few lingering issues that should be addressed before the paper is considered for publication.  
 
1 - The authors still need to add more detail on what guided their selection of covariates - e.g., 
prior studies (of withdrawa l or contraceptive use in general) and/or a conceptual framework. 
Surely there was a rationale for selecting variables like economic power and beliefs in the 
"naturalness" of hormonal methods. The authors should make this more explicit; 1 -2 sentences 
with some key references should suffice.  
 
2 - "Exploratory" is the best descriptor of the analytic approach and still only appears once in the 
paper (in Methods, "...given the exploratory nature of this analysis"). The authors should frame 
this as an "explorato ry" study further up, at the end of the Introduction. The authors have added 
some more references to the cross -sectional nature of the study, but that pertains to study design 
and not to the analytic approach.  
 
3 - At the beginning of Results, mention tha t Tier 1/2 is comprised almost solely of IUD and pill 
users.  
 
4 - The title should be more precise, as it currently connotes prevalence (rather than correlates) 
of withdrawal use.  
 
5 - The inclusion of unmarried women in the analysis still strikes me as p roblematic, especially 
considering the significant findings for economic power. This variable should really be coded as 
missing for unpartnered women, but they are lumped with the reference ("no") group. The 
authors should address this as a limitation and be cautious in their interpretation of this particular 
finding.  
 
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.  
 
Unable to assess  
 
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 statis tics in the manus cript 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 am able to assess the statistics  
 
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 questions:  
 
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 that may in an y 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 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  
 
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 f or 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 in cluded as confidential comments 
to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal