Peer Review History

Original SubmissionOctober 2, 2020
Decision Letter - Gang Han, Editor

PONE-D-20-30134

Rethinking remdesivir for COVID-19: a Bayesian reanalysis of trial findings

PLOS ONE

Dear Dr. Hoek,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we have decided that your manuscript does not meet our criteria for publication and must therefore be rejected.

This is because both reviewers expressed many concerns and one of them recommended rejection. I have tried to invite the third reviewer but did not receive any feedback by now. 

I am sorry that we cannot be more positive on this occasion, but hope that you appreciate the reasons for this decision.

Yours sincerely,

Gang Han, PhD

Academic Editor

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: Partly

Reviewer #2: Partly

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

Reviewer #1: Yes

Reviewer #2: No

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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: No

Reviewer #2: Yes

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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: Yes

Reviewer #2: Yes

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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: Rethinking remdesivir for COVID-19:

a Bayesian reanalysis of trial findings

By: Sarahanne M. Field, Joyce M. Hoek, Ymkje Anna de Viries, Merie-Marie

Pittelkow, Maximilian Linde, Jasmine H. Muradchanian, Don van Ravenzwaaij

Submitted to: PLOS ONE

Ms I.d. PONE-D-20-30134

Report: 11/15/2020

Major Comments:

Recently remdesivir received much attention internationally for its treatment

effect against the COVID-19. The existing three studies on the effect of

remdesivir gave ambiguous conclusions. The authors use a Bayesian method to

reanalyze the results of the tree studies, using non-informative priors, and

summary statistics reported from the three previous studies.

Their reanalysis of the ACTT-1 trial data shows that remdesivir outperforms

placebo for time to clinical recovery. However, the evidence that remdesivir

for mortality rate is ambiguous.

Their reanalysis of Wang et al. provides weak evidence against

remdesivir-treated patients improving more quickly than patients in the

placebo group. The reanalysis of the mortality rate data yielded moderate

evidence in favor of no effect.

Their reanalysis of the GS-US-540-5773 trial data largely supports Goldman

and colleagues’ null hypothesis of no difference between a 5-or 10-day

course of remdesivir.

The authors finding is interesting. My comments are below.

* The authors should give explanation why a Bayesian method is preferred

than a frequentist one for this problem?

* The authors should try to provide the data links, so the data become

public accessible. Or at least provide the summary statistics of the

data as they used in this paper, either in the text or in an Appendix.

This will help the public researchers to evaluate performance of remdivir

and the that of the existing studies on remdivir.

* The authors mentioned that Jeffreys-Zellner-Siow Bayes factors based

on Bayesian t-test and chi-squared test were used in the reanalysis.

Please discuss the advantage of this method vs the classical Bayes

factor.

Minor Comments:

* The authors mentioned that non-informative priors are used in their

analysis. As there are several different non-informative priors, please

specify which non-informative prior is used.

Reviewer #2: This manuscript used Bayes factor to re-analyze the three trials on Remdesivir for treating COVID-19. The manuscript is well-written but has very limited contribution to either statistical method or clinical guidance. There is no discussion of why BF is used and how it improves the conclusions. There is no discussion of using and how to use different prior information. The authors can consider combining information from the three trials to improve conclusion.

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Reviewer #1: Yes: Ao Yuan

Reviewer #2: No

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For journal use only: PONEDEC3

Revision 1

Reviewer #1

R1-1 The authors should give explanation why a Bayesian method is preferred than a frequentist one for this problem?

In our opinion, there are many advantages to Bayesian hypothesis testing over frequentist hypothesis testing, such as the ability to continually test as data comes in (sequential testing) and quantifying the likelihood of hypotheses relative to one another. In the context of this specific reanalysis, the main advantage is the ability to quantify evidence in favor of the null hypothesis (i.e., the absence of efficacy), which traditional p-values do not allow for.

When medicine regulators initially approved remdesivir, limited clinical trial data was available. In addition, one of the two available randomized placebo-controlled trials by Wang et al. could not be interpreted in a frequentist framework. Since we think it is important to include both trials in the regulatory efficacy assessment, we present a Bayesian reanalysis of the data.

We agree that the original manuscript did not state explicitly why a Bayesian method is preferred in this specific case. We expanded our explanation of the added value of a Bayesian approach at lines 12-13, 19-25 of page 2 and lines 5-13 of page 3 of our manuscript.

R1-2 The authors should try to provide the data links, so the data become public accessible. Or at least provide the summary statistics of the data as they used in this paper, either in the text or in an Appendix.

All data and analysis code is available on the public OSF repository at this url: https://osf.io/kdqt3. We now also included this link in our manuscript at line 24 of page 3.

R1-2: This will help the public researchers to evaluate performance of remdivir and the that of the existing studies on remdivir.

With regard to this second part of your comment, we wanted to facilitate the interpretation of our results by replacing the table of our results with a figure. This figure provides an overview of the current state of evidence for remdesivir in the treatment of COVID-19. The figure is presented at page 7 of our manuscript. We moved the table to the supplementary material.

R1-3 The authors mentioned that Jeffreys-Zellner-Siow Bayes factors based on Bayesian t-test and chi-squared test were used in the reanalysis. Please discuss the advantage of this method vs the classical Bayes factor.

The Jeffreys-Zellner-Siow Bayes factor has as distinguishing property the use of the Cauchy prior, centered on zero. Citing from van Ravenzwaaij & Etz (in press, available at https://psyarxiv.com/27ndb/):

"The Cauchy prior has some desirable mathematical properties (see e.g., Bayarri, Berger, Forte, & García-Donato, 2012; Consonni, Fouskakis, Liseo, & Ntzoufras, 2018), such as model selection consistency (for data generated under a model, the corresponding Bayes factor should go to infinity as sample size goes to infinity), predictive matching (a minimum sample size should exist for which the Bayes factor is 1, such that models are indistinguishable), and information consistency (a minimum sample size should exist for which data that result in test statistics that go to infinity should have corresponding Bayes factors that also go to infinity). Other priors may share some of these desirable properties, but the Cauchy prior has caught on as the go-to choice because it satisfies them all and is relatively easy to specify and interpret."

We included an explanation on lines 3-8 of page 5 of our manuscript.

R1-4 The authors mentioned that non-informative priors are used in their analysis. As there are several different non-informative priors, please specify which non-informative prior is used.

We now included a more extensive discussion of the methods that we used and our choice of priors under the subheadings ‘Bayesian two-sided t-test’ and ‘Bayesian chi-square test’ on page 4 and 5 of our manuscript and in our supplementary material.

Reviewer #2

R2-1 This manuscript used Bayes factor to re-analyze the three trials on Remdesivir for treating COVID-19. The manuscript is well-written but has very limited contribution to either statistical method or clinical guidance. There is no discussion of why BF is used and how it improves the conclusions.

As indicated in our response to R1-1, our main reason for conducting the Bayesian reanalyses is to be able to quantify pro-null evidence. Under a frequentist framework, it remains unclear whether non-significant results (such as those by Wang et al.) are due to lack of power or due to null effects. Perhaps more importantly, concerns about "perceived significance" should not be a reason for rejection at PLOS ONE, and the reviewer does not present any compelling methodological concerns that could motivate a rejection.

In addition, we disagree that our paper has limited contribution to clinical guidance. When remdesivir was first approved, only two relevant clinical trials were available. One of these trials could not be interpreted under a frequentist framework and was excluded from regulatory assessments of remdesivir. When evidence is limited, it is important that all available evidence can be assessed. We provide a method to do so.

As explained in our response to reviewer one, we did include a more explicit explanation of the added value of a Bayesian approach in this specific case in the introduction of our manuscript.

R2-2 There is no discussion of using and how to use different prior information.

We have added detailed information about the choice of priors for both the Bayesian t-test and the Bayesian chi-square test to both the manuscript (page 4 and 5) and in the supplementary material.

R2-3 The authors can consider combining information from the three trials to improve conclusion.

Thank you for your suggestion. We agree and are enthusiastic about combining information from the three trials, but as the data are quite different, we prefer to stick to combining the information qualitatively as we do in our current version of the manuscript. A (Bayesian) meta-analysis would not be justified, given the underlying assumptions. We explain our reasoning on lines 1-15 of page 4 of our manuscript.

Attachments
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Submitted filename: Response to Reviews Hoek, Field et al.docx
Decision Letter - Alan D Hutson, Editor

Rethinking remdesivir for COVID-19: a Bayesian reanalysis of trial findings

PONE-D-20-30134R1

Dear Dr. Hoek,

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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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,

Alan D Hutson

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

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

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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: Partly

**********

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

Reviewer #1: Yes

**********

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

**********

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

**********

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: Rethinking remdesivir for COVID-19:

a Bayesian reanalysis of trial findings

By: Sarahanne M. Field, Joyce M. Hoek, Ymkje Anna de Viries, Merie-Marie

Pittelkow, Maximilian Linde, Jasmine H. Muradchanian, Don van Ravenzwaaij

Submitted to: PLOS ONE

Ms I.d. PONE-D-20-30134-R1

Report: 05/21/2021

The authors addressed my comments. There are some parts still unclear.

* "the main advantage is the ability to quantify evidence in favor of the

null hypothesis". Do you mean that one can subjectively specify the prior

in favor of the null hypothesis? Is this an advantage or a way of imposing

personal opinion (which may be miss-leading)?

* "Since we think it is important to include both trials in the regulatory

efficacy assessment, we present a Bayesian reanalysis of the data".

As frequentist methods can also include multiple trials, please explain

what's unique for Bayesian on this point?

* The author mentioned that "the main advantage is the ability to quantify

evidence in favor of the null hypothesis", but they used a noninformative

prior, which does not favor the null nor the alternative. Please explain

how a noninformative prior can be in favor of the null hypothesis?

**********

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

Formally Accepted
Acceptance Letter - Alan D Hutson, Editor

PONE-D-20-30134R1

Rethinking Remdesivir for COVID-19: A Bayesian Reanalysis of Trial Findings

Dear Dr. Hoek:

I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department.

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 plosone@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. Alan D Hutson

Academic Editor

PLOS ONE

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