PONE-D-20-19930

Characteristics, laboratories, and prognoses of severe COVID-19 in the Tokyo metropolitan area: a retrospective case series

PLOS ONE

Dear Dr. Mori,

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Yoshiaki Taniyama, MD, 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: 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: This is a timely and well done review of the Tokyo experience with COVID-19. It provides some answers but mostly raises some helpful questions regarding the pathophysiology of COVID-19 PNA. Particularly informative was the discussion section where the authors compare the Tokyo experience to that in NYC and Italy. It seems that elevated BMI and hyperlipidemia are pertinent risk factors for COVID-19 PNA.

I would suggest editing of this paper by an individual who speaks English as their first and primary language. There were a number of spelling errors including "Severe" in the very first sentence.

Also, can you explicitly state the criteria for placing a patient in the prone position?

Seeing at the patients were all anticoagulated, were any bleeding complications encountered? eg: epistaxis, hemoptysis. Were INR, PT and PTT monitored? What was the range of these values in those patients who recovered?

Procalcitonin is misspelled- page 14

Ventilator is misspelled table 4.

Overall nice paper. Will add to the medical literature. With these few revisions it should be ready for publication.

Reviewer #2: This manuscript reports characteristics, laboratories, treatment associated cost in ICU of hospitalized COVID-19 patients in the Tokyo metropolitan area. It is a retrospective study with 45 patients, consisting 22 severe cases and 23 mild cases. Descriptive statistics and comparisons between 22 severe cases and 23 mild cases were performed with appropriated statistical methods. Even though the sample size is small, these data may provide valuable information about the observed differences in characteristics, laboratories between severe cases and mild cases. And also reveals the treatment cost in Japan. Below are my questions.

Page 4, 1st paragraph of Patients and admission criteria, should “April 10” be “March 10” as the start time point?

Page 15, Table 4 shows 17( 77.3%) survived in S group. Should 77.3% be discharged rate because the 1st line of page 16 indicates a 86.3% survival rate? Please make those numbers, labels and descriptions be consistent.

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Reviewer #1: No

Reviewer #2: No

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Characteristics, laboratories, and prognosis of severe COVID-19 in the Tokyo metropolitan area: A retrospective case series

PONE-D-20-19930R1

Dear Dr. Mori,

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,

Yoshiaki Taniyama, MD, PhD

Academic Editor

PLOS ONE

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 #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 #2: (No Response)

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

Reviewer #2: (No Response)

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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 #2: (No Response)

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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 #2: (No Response)

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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 #2: (No Response)

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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 #2: No