Reviewer ’s report  
 
Title: The effect of a diabetes prevention program on dietary quality in women with previous 
gestational diabetes  
 
Version: 0 Date: 07 Apr 2019  
 
Reviewer: CHRISTIAN GOEBL  
 
Reviewer's report:  
 
This is a secondary analysis of the MAFDA -DPP study aiming to assess the effectiveness of a 
group -based lifestyle intervention strategy for improvement in dietary quality in pGDM women 
within the first postnatal year. By using a FFQ the authors found almost no changes in ARFS in 
ITT analysis, although some differences were observed in per -protocol set analysis.  
 
This is an interesting area of study. I have following suggestions:  
1. The Introduction section is overly long and should be shortened.  
 
2. The author s should clarify that this is a secondary analysis of the MAGDA -DPP cohort with 
different primary outcome.  
 
3. Authors used ADIPS criteria with FG>5.5 mmol and 2hG >8 mmol as reported elsewhere 
(ref 26 in the manuscript). However, the thresholds for GDM dia gnosis should be included in 
this manuscript as well.  
 
4. Statistical analysis: add "two -sided" 5% significance level. Mixed model: random intercept, 
random slope or both? Any other specification? Normality assumption does not hold for 
scores and rank based  inference might be more appropriate. nparLD package in R could be 
helpful (perhaps as a supporting approach)  
 
5. Sample size calculation was performed for differences in FPG not FFQ analysis. Maybe this 
secondary analysis has limited power?  
 
6. Results, lin es 240 -242: Differences between intervention and controls do not necessarily 
affect the outcome, if randomisation was adequately performed. Thus, please describe the 
randomisation procedure with more detail.  
 
7. However, PPS analysis could be critisized bec ause the protection of randomisation gets lost. 
Therefore, adjustment for baseline differences by multivariable models could be helpful.  
 
8. Tables are hard to read. I would suggest to report only the difference in time. Moreover, 
appropriate visualisation of the most important findings could be helpful.  
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 t he 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 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, fees, funding, or salary from an  
organisation that may in any way gain or lose financially from the publication of this  
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2. Do you hold any stocks or shares in an organisation that may in any way gai n 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 salar y 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 answe r 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 interest  
 
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