PONE-D-20-02141

Randomized controlled evaluation of the psychophysiological effects of social support stress management in healthy women

PLOS ONE

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PLOS ONE

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Partly

Reviewer #3: No

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: No

Reviewer #3: N/A

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3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). 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: Yes

Reviewer #2: No

Reviewer #3: No

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4. 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: No

Reviewer #2: Yes

Reviewer #3: No

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: There are minor errors in citation, typography and grammar that need to be addressed:

- page 3: "a survey in 2012 showed that ... (American Psychological Association, 2012)" the source is not listed in the References. Besides it would be helpful for the reader to know, in which country this survey has been conducted. Please check all references for accuracy and completeness.

- page 3: please change "psychoscial stressor" into "psychosocial stressor"

- page 4: please change "effects of a intervention" into "effects of an intervention"

- page 10: please change "Qui-square tests" into "Chi-square tests"

- page 14: please change "although this studies" into "although these studies"

- page 15: please change "... indicating no effect of the intervention on acute stress responses." into "indicating no effect of the intervention on acute physiological stress response."

other comments:

In the discussion section the following is stated: (page 15) "With regard to our intervention, this finding [i.e. intervention based on social support failed to elicit effects on the cardiovascular stress response] is possible due to the protocol of the TSST, which clearly prevents any possibility to use or obtain social support, as the audience of confederates is instructed to interact in a neutral way with the participants and not to give any positive verbal or non-verbal feedback or signs of communication other than that specified in the manual (Kirschbaum et al., 1993)."

Is this really so? What about accessing internalized social support? In fact, in the Appendix A (page 26) the authors themselves declare that "the use of imagined persons as social support in times when no-one is directly available" was a key topic in the 5th session of their social support mangangement intervention. I suggest the authors to discuss the relevance of further investigations regarding the stress buffering potential of social support in the absence of a support giver and/or receiver, e.g. imagined, internalized or even embodied social support, or even "inner child" work.

Figure 1: Recruitment and participants flow through the study.

- If possible, please specify the reasons for declined participation after randomization.

- If possible, please specify the reasons for insufficient training attendance.

Reviewer #2: This is a well-presented paper that reported a randomised controlled trial of 53 healthy women who were randomly allocated to receive a two-week social support stress management intervention or a waitlist control condition. Assessments were conducted at baseline, post-intervention and follow-up four weeks later.

As the authors pointed out in the discussion, the total sample size was rather small which limited the statistical power to detect small but clinically relevant differences between two conditions. The assumptions used for sample size calculation as reported in the paper, were also different from those stated in the original study protocol. Was this a post-hoc power calculation? Without a clear definition of the primary outcome, which is compulsory for a randomised controlled trial, it is hard to judge whether the calculated sample size was indeed adequate.

The principle of ITT is to include all randomised participants (i.e. 28 intervention and 25 control condition), regardless of the treatment they actually received during the trial. The authors did not define the ITT population used for the trial, and only included 20 participants in each condition (Figure 1 and Table 1). As reported in the literature, the last value carried forward approach is simple to administer but can give a biased estimate of the treatment effect and underestimate the variability of the estimated result. A more robust approach is to use multiple imputations that account for imputation uncertainty, or advanced mixed models with repeated measures. Regardless, the amount of missing data reported in the study is of concern and the results based on a further reduced sample size must be interpreted with caution.

Baseline imbalance was tested between two conditions, although any observed differences between groups should only have occurred by chance if the randomisation was implemented properly. Please provide more details on how the randomisation list was generated and by whom.

How was the effect size quantified and for which time point? What was the rationale to measure the outcomes at both post-intervention and follow-up? For repeated measures analysis, the time point should be fitted in the model as well as its interaction with the randomised condition so that the group difference could be tested at each time point. Alternatively, the authors could run separate regression analysis at each of the two visits post randomisation and report the estimated effect sizes with associated 95% confidence intervals. Note that F-statistics and p-values alone provide no information on the size of intervention effect. For all outcome measures, please explain the range of each calculated scale and how it is interpreted. Table 1 should report the mean and standard deviation (SD) rather than SEM. Please also follow the suggested table templates in the CONSORT 2010 statements and report all outcome measures in the table with descriptive statistics and estimated group differences with 95% CIs.

Reviewer #3: General comments

The objective of the article is to assess the effect of an intervention focused on training interpersonal skills under

different dimensions of the stress response. In terms of the experimental design, the study has issues that must be

clarified. Among others, it would have been good to implement a pre-post design and thus rule out individual

differences in the stress response. With respect to the impact of the study, the scope and novelty of the (only)

positive result report is not completely clear. Indeed, the authors of the article recognize existing evidence in this

direction (e.g., Gaab et al., 2003; Storch et al., 2007; Martín et al., 2011).

Ultimately, the experiment does not present results in the physiological dimension, but rather in a self-reporting measurement, which is to be expected and not entirely relevant (e.g., Reyes et al. 2005). In fact, reporting the belief of a “stress reduction” does not seem to be connected to physiological changes, which is why it does not seem correct to conclude the article in terms of stress as such. To sum up and considering all the aspects indicated, I believe it is an initial

investigation, a first experimental approach that needs to be redesigned. I recommend that the article be re-

submitted after correcting the experimental design.

Specific points

1/ present Appendix 1 in the main text.

2/ I do not fully understand if the knowledge of the participants regarding the intervention could explain the

effect evidenced (on stress perception, PSS).

3/ If the study tries to insist on the importance of training in interpersonal skills, the results are not in line with

this objective. At least this point must be addressed in more detail in the discussion. 

4/ The authors maintain: “The TSST elicited an increase in cortisol, heart rate and state anxiety and a decrease

in RMSSD”. Indeed, the authors of the article recognize existing evidence in this direction (e.g., Gaab et al.,

2003; Storch et al., 2007; Martín et al., 2011).However, this statement is not statistically justified in the text.

5/ It is recommended that the writing and format be revised in detail.

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Reviewer #1: Yes: Marko Nedeljkovic

Reviewer #2: No

Reviewer #3: No

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Randomized controlled evaluation of the psychophysiological effects of social support stress management in healthy women

PONE-D-20-02141R1

Dear Dr. Gaab,

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.

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Kind regards,

Johannes Fleckenstein

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

As you will see below, Reviewer 3 has outstanding concerns with the manuscript. However, having evaluated the manuscript myself I do not consider any further revisions to be necessary.

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #3: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #3: Partly

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3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #3: Yes

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4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). 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: Yes

Reviewer #3: Yes

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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 #3: Yes

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6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: Thank you for thoroughly addressing all my previous comments. From my point of view, there are no further ammendments pending.

Reviewer #3: The aim of the article is to examine the effect of a social support stress management intervention on psychophysiological stress responses as well as self-reported stress in healthy women. Results suggest that he intervention had no effect on the physiological (stress) measure across groups (HRV, Cortisol concentration), but only a small effect on self-reported stress.

In general terms, it seems to be a well-developed clinical trial with an adequate control of the psychological and physiological indicators. However, unfortunately, I do not recommend the publication, mainly due to the lack of clarity regarding the stress effect reported. Ultimately, the authors should clarify / justify / argue why the null results in physiology might not be relevant for the type of intervention implemented. And from there, why the small effect on the self-report of stress could be relevant, when it does not seem to persist in the follow-up stage. Even if it could be the case that the intervention effect is presented exclusively at the self-report level, the authors should explain if such effect is not simply due to their knowledge of the experimental protocol (i.e., the “discuss of the intervention” explicit on the first session).

Our suggestion is that the team of authors carry out a new and detailed review of the experimental protocol. If the reported stress effect is consistent, then a replication of this effect is desirable, experimentally controlling the knowledge that the participants have of the intervention. Associated with the above, the authors should better argue why the stress effect is (and should be in this type of intervention) independent of the expected effect on physiology.

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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 #3: Yes: Gabriel Reyes M