Study protocol of a breathing and relaxation intervention included in antenatal education: A randomised controlled trial (BreLax study)

Vanessa Leutenegger; Frank Wieber; Deirdre Daly; Leila Sultan-Beyer; Jennifer Bagehorn; Jessica Pehlke-Milde

doi:10.1371/journal.pone.0308480

Peer Review History

Original SubmissionFebruary 29, 2024
5 Jun 2024 Decision Letter - David Chibuike Ikwuka, Editor PONE-D-24-06197Study protocol of a breathing and relaxation intervention in antenatal education: a randomised controlled trial (BreLax study)PLOS ONE Dear Dr. Leutenegger, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. Please submit your revised manuscript by Jul 19 2024 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. 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Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. Does the manuscript provide a valid rationale for the proposed study, with clearly identified and justified research questions? The research question outlined is expected to address a valid academic problem or topic and contribute to the base of knowledge in the field. Reviewer #1: Yes Reviewer #2: Yes ******** 2. Is the protocol technically sound and planned in a manner that will lead to a meaningful outcome and allow testing the stated hypotheses? The manuscript should describe the methods in sufficient detail to prevent undisclosed flexibility in the experimental procedure or analysis pipeline, including sufficient outcome-neutral conditions (e.g. necessary controls, absence of floor or ceiling effects) to test the proposed hypotheses and a statistical power analysis where applicable. As there may be aspects of the methodology and analysis which can only be refined once the work is undertaken, authors should outline potential assumptions and explicitly describe what aspects of the proposed analyses, if any, are exploratory. Reviewer #1: Partly Reviewer #2: Yes ****** 3. Is the methodology feasible and described in sufficient detail to allow the work to be replicable? Descriptions of methods and materials in the protocol should be reported in sufficient detail for another researcher to reproduce all experiments and analyses. The protocol should describe the appropriate controls, sample size calculations, and replication needed to ensure that the data are robust and reproducible. Reviewer #1: No Reviewer #2: Yes ****** 4. Have the authors described where all data underlying the findings will be made available when the study is complete? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception, at the time of publication. The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: No Reviewer #2: No ****** 5. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes Reviewer #2: Yes ****** 6. Review Comments to the Author Please use the space provided to explain your answers to the questions above and, if applicable, provide comments about issues authors must address before this protocol can be accepted for publication. You may also include additional comments for the author, including concerns about research or publication ethics. You may also provide optional suggestions and comments to authors that they might find helpful in planning their study. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: The paper is quite well written and well organized. I confine my comments to statistical matters. L174: Why verify eligibility by phone? Are there no baseline (clinical) variables to be collected at the onset? Or values of baseline variables have to meet certain threshold before admission to the trial? If so, eligibility can be confirmed on site during the baseline interview. L180: What is the interpretation of an effect size of 0.75 in the context of the trial. L183: The 20% attrition rate comes from nowhere without justifications. This results in a sample size of of 35 subjects to be recruited for each arm. The hospital has 1800 births and there was a brief discussion of contamination. So why not perform the trial staggered over time to minimize contamination? L189: Why have the midwife use envelopes to randomize subjects into group membership. It is the same reason why you don’t want the same statistician to randomize the trial and perform the analysis. L334 ‘the possibility of multiple imputation’ will be examined. This is very vague. Please elaborate. Identify situations if and when you will use multiple imputation. L344 You also reference doing the analyses using a serious of linear mixed effects models. What models do you have in mind? Please provide more details and display the regression models and show what are the random and fixed effects for added clarity Further comments. Throughout, the methodology seems to assume the outcome is normally distributed. Where are the checks and what is the proposed methodology if they are not normally distributed? (I actually don't understand why we need to fill in this box when the full report is enclosed as a pdf). Reviewer #2: The abstract by PLOS ONE's general guideline should not exceed 300 words; please summarise to reduce the words. Additionally, you used Harvard reference style; PLOS uses the Vancouver” reference style. Please, authors should take note of this and do the needful throughout the text and apply same to the list of references by numbering in the order in which they appear in the text. The reference numbers in the text should be in brackets. There were one or two spelling errors and missing word(s), e.g. "pharmalogical" (line 89) which I believe ought to be pharmacological. Authors should please read the manuscript thoroughly and religiously to correct the errors so observed. How do the authors reconcile the statement (lines 255 and 256) under antenatal education classes with that in randomisation and allocation (lines 186 and 187)? ****** 7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: No Reviewer #2: Yes: Dr Stanley M Maduagwu ******** [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step. Attachments Attachment Submitted filename: Referee report for Brelax study.pdf https://doi.org/10.1371/journal.pone.0308480.r001
Revision 1
5 Jul 2024 Author Response Responses to reviewers' comments (also shown in the "Response to reviewers" document) 2. 1. Is the protocol technically sound and planned in a manner that will lead to a meaningful outcome and allow testing the stated hypotheses? Thank you for this advice. As we recognise that some aspects of the methodology and analysis may need to be refined as the work progresses, we will set out potential assumptions from the outset. This will provide transparency about the principles of our research approach. In addition, we will describe which aspects of the analyses we propose are exploratory. This distinction between confirmatory and exploratory analyses is important to ensure the integrity of our findings. For this reason, we have substantiated the data analysis. 3. Is the methodology feasible and described in sufficient detail to allow the work to be replicable? Thank you for the useful advice, which we have implemented as follows in relation to the sample size calculation. The sample size calculation was based on a previous study (Ip et al., 2009), and the effect size of 0.75 used for this was therefore a rather conservative figure. The attrition rate of 20% was based on the assumption that the women are closely monitored by the midwives and the specialists involved in the clinic, which is why it is assumed that pathological pregnancies are more likely to be the reason for possible exclusions. In addition, participation in the study is not very time-consuming with an antenatal education class as an intervention and three 20-minute questionnaires. Accordingly, L338 till L350 are defined in more detail so that repeatability and transparency are ensured. 4. Have the authors described where all data underlying the findings will be made available when the study is complete? Thank you for pointing this out, this issue was clearly not addressed enough. No data sets were generated or analyzed during the current study. All relevant data from this study will be made available upon completion of the study. The ethics protocol was made available to the public on clinicaltrial.gov. Reviwer 1#: Further comments: L174: Why verify eligibility by phone? Are there no baseline (clinical) variables to be collected at the onset? Or values of baseline variables have to meet certain threshold before admission to the trial? If so, eligibility can be confirmed on site during the baseline interview. As the first contact with potential participants is usually made by telephone to conduct the study information, possible exclusion criteria, such as a primary caesarean section, are already identified (see Section “Participants”). The exclusion criteria are then comprehensively checked in the baseline survey and women are excluded on the basis of these. L180: What is the interpretation of an effect size of 0.75 in the context of the trial. Based on previous comparable studies, the moderate to high effect size of 0.75 was set. This assumption would mean that the BreLax intervention could have a substantial impact on self-efficacy (Leutenegger et al., 2022). L183: The 20% attrition rate comes from nowhere without justifications. This results in a sample size of of 35 subjects to be recruited for each arm. The hospital has 1800 births and there was a brief discussion of contamination. So why not perform the trial staggered over time to minimize contamination? The study is part of a PhD project and is therefore limited in terms of both time and funding. For this reason, although a phased implementation was discussed, it was not considered feasible for the reasons mentioned. The 20% attrition rate is due to the fact that the women in the clinic are cared for relatively closely by the gynaecological specialists and midwives, which is why a loss through follow-up is rather unlikely. In addition, a 20% attrition rate was recommended in the statistical consultation due to the academic degree of the project manager. L189: Why have the midwife use envelopes to randomize subjects into group membership. It is the same reason why you don’t want the same statistician to randomize the trial and perform the analysis. Yes, that is correct. The study midwife has allocated all classes taking place in the coming year with the help of envelopes during the study planning phase. L334 ‘the possibility of multiple imputation’ will be examined. This is very vague. Please elaborate. Identify situations if and when you will use multiple imputation. In the proposed study, we will explore the possibility of multiple imputation when we encounter missing data. The decision to use multiple imputation will depend on the amount and type of missing data and the requirements of our analysis. L344 You also reference doing the analyses using a serious of linear mixed effects models. What models do you have in mind? Please provide more details and display the regression models and show what are the random and fixed effects for added clarity During the planning of the analysis, the random intercept model and the random intercept and slope model were identified. The random intercept model would allow the baseline self-efficacy data to vary in the direction of birth. The random intercept and slope model if the effect of the BreLax intervention is expected to vary between women in the study. The randomised slope would allow for each woman to have her own unique response to the intervention over time. For the following reasons, this model was assumed in the protocol. Further comments: Throughout, the methodology seems to assume the outcome is normally distributed. Where are the checks and what is the proposed methodology if they are not normally distributed? Thank you for pointing this out. These were addressed individually in the respective points (data analysis) and a specific explanation was provided in the revised manuscript in the section on data analysis (Line 326-354). Reviewer2# Further comments: Thank you very much for your comments. The abstract has been revised according to the word recommendation. The citation style has been changed accordingly and the language corrections have been made. Participating women register themselves for their chosen antenatal education classes. During the planning phase, all advertised courses for the coming year were randomised (intervention yes / no), which is why the women do not know which course they are attending. The information section on breathing and relaxation exercises is included in both classes, but not the exercise sequences or the online guide. This point could potentially be critical when the women discuss possible exercises within the course. In order to identify this bias, the last questionnaire collects information on this, such as "Have you had contact with women from other courses?", "Did you receive any further information?". https://doi.org/10.1371/journal.pone.0308480.r002
25 Jul 2024 Decision Letter - David Chibuike Ikwuka, Editor Study protocol of a breathing and relaxation intervention included in antenatal education: a randomised controlled trial (BreLax study) PONE-D-24-06197R1 Dear Dr. Leutenegger, We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements. Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication. An invoice will be generated when your article is formally accepted. Please note, if your institution has a publishing partnership with PLOS and your article meets the relevant criteria, all or part of your publication costs will be covered. Please make sure your user information is up-to-date by logging into Editorial Manager at Editorial Manager® and clicking the ‘Update My Information' link at the top of the page. If you have any questions relating to publication charges, please contact our Author Billing department directly at authorbilling@plos.org. If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. Kind regards, David Chibuike Ikwuka, Ph.D. Academic Editor PLOS ONE Additional Editor Comments (optional): Reviewers' comments: https://doi.org/10.1371/journal.pone.0308480.r003
Formally Accepted
6 Aug 2024 Acceptance Letter - David Chibuike Ikwuka, Editor PONE-D-24-06197R1 PLOS ONE Dear Dr. Leutenegger, I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now being handed over to our production team. At this stage, our production department will prepare your paper for publication. This includes ensuring the following: * All references, tables, and figures are properly cited * All relevant supporting information is included in the manuscript submission, * There are no issues that prevent the paper from being properly typeset If revisions are needed, the production department will contact you directly to resolve them. If no revisions are needed, you will receive an email when the publication date has been set. At this time, we do not offer pre-publication proofs to authors during production of the accepted work. Please keep in mind that we are working through a large volume of accepted articles, so please give us a few weeks to review your paper and let you know the next and final steps. Lastly, if your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. If we can help with anything else, please email us at customercare@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Dr David Chibuike Ikwuka Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0308480.r004

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