PONE-D-22-26070Risk factors for mechanical ventilation and ECMO in COVID-19 patients admitted to ICU: A multi-center retrospective observation studyPLOS ONE

Dear Dr. Takazawa,

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.

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ACADEMIC EDITOR: Manuscript ID PONE-D-22-26070 entitled "Risk factors for mechanical ventilation and ECMO in COVID-19 patients admitted to ICU: A multi-center retrospective observation study" which you submitted to the PLOS ONE, has been reviewed. A minor revision decision is applied to your manuscript according to the reviewer comments.

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Gulali Aktas

Academic Editor

PLOS ONE

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Additional Editor Comments :

Dear Dr. Takazawa

Manuscript ID PONE-D-22-26070 entitled "Risk factors for mechanical ventilation and ECMO in COVID-19 patients admitted to ICU: A multi-center retrospective observation study" which you submitted to the PLOS ONE, has been reviewed. The comments of the reviewer(s) are included at the bottom of this letter.

The reviewer(s) have suggest some minor revisions to your manuscript. Therefore, I invite you to respond to the reviewer(s)' comments and revise your manuscript.

Comments of Reviewer 1

Manuscript is a clear, concise, and well-written with relevant introduction. Conclusion in abstract should be written more clearly and precisely. In Methodology explain terms PACHE II score, SOFA score, and how did you calculate them.

Some values in Table 1 and others are express as numbers and percentages, please write n(%) for that variables. If it is possible, please divide Table 2 and Table 3 into two or more tables.

Comments of Reviewer 2

The manuscript PONE-D-22-26070 is a well prepared original article about risk factors of intensive care either with ECMO or mechanical ventilation in Covid-19 patients. I congratulate authors for such a good work. My comments about the sections of the manuscript are as following:

Title is relevant as keywords after abstract which is an adequate summary of the study.

Rationale and aims are clearly mentioned in introduction

Methods and the study design expressed perfectly. Statistical analyses are correct and adequate for the study design.

Presentation of the results is clear. Tables improved the readiness. However, unit of all variables must be stated in the tables. I advise n,% for categorical variables.

Discussion is fair enough. Yet, I suggest discussing the role of inflammatory burden on necessity of ECMO or mechanical ventilation. Studies in literature reported higher inflammatory markers in serious Covid-19 cases compared to the patients with mild or moderate disease (Hematology 2021;26(1):529-542. DOI: 10.1080/16078454.2021.1950898). Discuss.

Conclusions must be clarified. The statement 'This study revealed several risk factors on ICU admission that are related to the 261 need for subsequent MV or ECMO in COVID-19 patients admitted to the ICU.' is not the best conclusion that could be drawn from the study.

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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: Yes

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

Reviewer #1: Yes

Reviewer #2: Yes

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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: 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: Manuscript is a clear, concise, and well-written with relevant introduction. Conclusion in abstract should be written more clearly and precisely. In Methodology explain terms PACHE II score, SOFA score, and how did you calculate them.

Some values in Table 1 and others are express as numbers and percentages, please write n(%) for that variables. If it is possible, please divide Table 2 and Table 3 into two or more tables.

Reviewer #2: The manuscript PONE-D-22-26070 is a well prepared original article about risk factors of intensive care either with ECMO or mechanical ventilation in Covid-19 patients. I congratulate authors for such a good work. My comments about the sections of the manuscript are as following:

Title is relevant as keywords after abstract which is an adequate summary of the study.

Rationale and aims are clearly mentioned in introduction

Methods and the study design expressed perfectly. Statistical analyses are correct and adequate for the study design.

Presentation of the results is clear. Tables improved the readiness. However, unit of all variables must be stated in the tables. I advise n,% for categorical variables.

Discussion is fair enough. Yet, I suggest discussing the role of inflammatory burden on necessity of ECMO or mechanical ventilation. Studies in literature reported higher inflammatory markers in serious Covid-19 cases compared to the patients with mild or moderate disease (Hematology 2021;26(1):529-542. DOI: 10.1080/16078454.2021.1950898). Discuss.

Conclusions must be clarified. The statement 'This study revealed several risk factors on ICU admission that are related to the 261 need for subsequent MV or ECMO in COVID-19 patients admitted to the ICU.' is not the best conclusion that could be drawn from the study.

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6. 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: Ozge Kurtkulagi

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Risk factors for mechanical ventilation and ECMO in COVID-19 patients admitted to the ICU: A multicenter retrospective observational study

PONE-D-22-26070R1

Dear Dr. Takazawa,

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 for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, 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,

Gulali Aktas

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Authors were very responsive to the reviewers' comments. The manuscript is improved significantly. Therefore it is acceptable for publication.

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 #2: 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 #2: Yes

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

Reviewer #1: Yes

Reviewer #2: 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 #2: 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 #2: 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: (No Response)

Reviewer #2: All review suggestions were followed b y the authors. Well done. There is nothing more that require further revision. I recommend publication.

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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 #2: No

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