Reviewer’s report
Title: Blood Pressure after PREeclampsia/HELLP by SELF monitoring (BP-PRESELF): rationale
and design of a multicenter randomized controlled trial
Version: 1 Date: 23 Sep 2019
Reviewer: Erkan Kalafat
Reviewer's report:
This is a much needed research in women's health and I congratulate the authors for planning this
study. I do wish them luck and study execution without any major problems. My suggestions are listed
below.  
1. Lines 32 to 33: I agree that HDP is a much neglected risk factor for CVD risk but saying it has the
strongest association may be unsubstantiated. Causality is a matter of judgment based on the available
evidence. As of yet, the association of HDP with CVD risk in the presence of multiple confounders is
not clear.
Haug et al. Association of Conventional Cardiovascular Risk Factors With Cardiovascular Disease
After Hypertensive Disorders of Pregnancy: Analysis of the Nord-Trondelag Health Study. JAMA
Cardiol. 2019;4:628-635.
2. Line 34 - HDP complicate 10-15% of all pregnancies - Please provide reference.
3. Lines 45 - 48. Please provide some more solid context for why HBPM may be beneficial for this at
risk population compared to conventional care with planned visits. The advantages over non-structured
follow-up and relying on incidental BP measurements are obvious but it is not the comparison here.
4. Lines 96-98. Women with a history of HDP have an increased risk of hypertension immediately high
after their HDP pregnancy. The cited reference is investigating a specific time period but the sentence is
misleading. 
5. Lines 109-110. The age interval is a bit odd given the context of this study. Is this a formal inclusion
criteria? According to Behrens et al, chronic hypertension risk is most highly elevated in the first 2
years following delivery and remains stable for more than a decade from that point on. Why did you
specifically target this population over women who just delivered with an HDP? Please elaborate. 
6. Lines 122-123. Block randomization (variable or not) may introduce significant bias in an open label
RCT. Even though the primary outcome is feasibility, imbalanced covariate distribution may also affect
your results which is a known issue with block randomization. 
7. Lines 123. Please provide details of what 'usual care' entails. 
8. Lines 110-111. Please specifically state how many centers are participating in this study. 
9. I imagine reasons for non-adherence will be one of the formal study outcomes.
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.
Unable to assess
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 am able to assess the statistics
Quality of written English
Please indicate the quality of language in the manuscript:
Acceptable
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