PONE-D-19-17979

Thirty-day readmission and return to acute care after hospitalization for people who experience imprisonment in Ontario, Canada: A retrospective cohort study

PLOS ONE

Dear Dr. Kouyoumdjian,

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.

We would appreciate receiving your revised manuscript by Oct 27 2019 11:59PM. When you are 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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Lars-Peter Kamolz, M.D., Ph.D., M.Sc.

Academic Editor

PLOS ONE

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2. In ethics statement in the manuscript and in the online submission form, please provide additional information about the patient records used in your retrospective study. Specifically, please ensure that you have discussed whether all data were fully anonymized before you accessed them and/or whether the IRB or ethics committee waived the requirement for informed consent. If patients provided informed written consent to have data from their medical records used in research, please include this information.

3. Please correct your reference to "p=0.000" to "p<0.001" or as similarly appropriate, as p values cannot equal zero.

4. We noticed you have some minor occurrence of overlapping text with the following previous publication(s), which needs to be addressed:

- Kouyoumdjian, Fiona G., et al. "The health care utilization of people in prison and after prison release: A population-based cohort study in Ontario, Canada." PloS one 13.8 (2018): e0201592.

Khanna, Sumeet, et al. "Health care utilization by people with HIV on release from provincial prison in Ontario, Canada in 2010: a retrospective cohort study." AIDS care 31.7 (2019): 785-792.

 The text that needs to be addressed involves the first paragraph of the Introduction.

In your revision ensure you cite all your sources (including your own works), and quote or rephrase any duplicated text outside the methods section. Further consideration is dependent on these concerns being addressed.

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We will update your Data Availability statement on your behalf to reflect the information you provide.

6. Thank you for stating the following in the Acknowledgments Section of your manuscript:

"This study was supported by ICES, which is funded by an annual grant from the Ontario Ministry of Health and Long-Term Care. The opinions, results and conclusions reported in this paper are those of the authors and are independent from the funding sources. We  acknowledge the Ontario Ministry of Community Safety and Correctional Services, which provided data for the study. No endorsement by ICES, the Ontario Ministry of Health and Long-Term Care, or the Ministry of Community Safety and Correctional Services is intended or should

be inferred. Parts of this material are based on data and/or information compiled and provided by

CIHI. However, the analyses, conclusions, opinions and statements expressed in the material are

those of the authors, and not necessarily those of CIHI.

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Please remove any funding-related text from the manuscript and let us know how you would like to update your Funding Statement. Currently, your Funding Statement reads as follows:

"FK received funding from Physicians' Services Incorporated Foundation (15-22)."

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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: 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: No

Reviewer #2: 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: 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 manuscript investigates the readmission and return to acute care after hospitalization among persons who experienced incarcerations and persons from the general population. This is an important research question, as the released prisoners constitute an underserved population and because their health care use is not well understood. The manuscript relies on a large sample size with a sound methodology. However, there are some limitations that should be addressed.

Whole paper

1. The literature more commonly uses “emergency department visits” rather than “return to acute care”.

Abstract

2. I found the abstract very confusing at first read. I am afraid it is not readable as a stand-alone piece. It should be written more clearly. The results section is very long and the conclusions are almost absent. I did not understand the Methods at first read.

Introduction

3. The introduction is very short. There are some studies addressing health care (and use of emergency department) among (released) prisoners. This literature should be presented as well.

As it is not possible to understand the reasons of readmission or return to acute care, I suggest to avoid mentioning it at the first place in the Introduction.

Methods

4. The most important shortcoming is the presence of the incarcerated prisoners and the potential lack of power. The non-significant findings are not interpretable and there are important issues (prisoners possibly released). I suggest to remove this group from the sample and to focus on released prisoners and general population.

5. What about released prisoners who are reincarcerated within 6 months?

6. Using a random hospitalization appears as a limitation of the study design. The rationale for this choice instead of using the first hospitalization should be given.

7. Please add detailed information on variables assessed in the study.

8. Please also give a rationale for using a 30-day readmission or return to acute care cut-off.

Results

9. The 7-day outcome is mentioned for the first time p. 9 in the Results section. It should be included in the study’s objective with its rationale and in the Methods section.

10. An important missed variable is the reason for hospitalization. It should be controlled for to achieve a better understanding of the results.

Discussion

11. Released prisoners are more likely to visit emergency departments in comparison with the general population. This may be because they have no GP, no information on their own health insurance, or no money to pay extra fees. It does not mean that they have worse outcomes after hospitalization. This should be discussed in the paper. Information on health care fees in the Canadian health care system should also be included.

Reviewer #2: This study is interesting for several reasons:

- large samples of people

- lack of data on care and hospitalizations for people in prison and after release

- comparison with the general population

However, for the method, why the 3 groups do not have the same number of people, since the objective was to compare them.

For the results, it is a little difficult to understand why there is such a difference between readmission and return to acute care. Information on the reasons for using non-hospitalized emergencies would deserve to be developed. Interpretation is possibly very much related to the functioning of the health care system in Ontario.

Minor comments:

Introduction

- Line 62: abreviation “emergency department (ED)” already indicated line 46

Methods

- Line 84: define ICES

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Reviewer #1: No

Reviewer #2: No

[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 to be viewed.]

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PONE-D-19-17979R1

Thirty-day readmission after medical-surgical hospitalization for people who experience imprisonment in Ontario, Canada: A retrospective cohort study

PLOS ONE

Dear Dr. Kouyoumdjian,

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.

We would appreciate receiving your revised manuscript by Jan 03 2020 11:59PM. When you are 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.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter.

To enhance the reproducibility of your results, we recommend that if applicable you deposit your laboratory protocols in protocols.io, where a protocol can be assigned its own identifier (DOI) such that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols

Please include the following items when submitting your revised manuscript:

• A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). This letter should be uploaded as separate file and labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. This file should be uploaded as separate file and labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. This file should be uploaded as separate file and labeled 'Manuscript'.

Please note while forming your response, if your article is accepted, you may have the opportunity to make the peer review history publicly available. The record will include editor decision letters (with reviews) and your responses to reviewer comments. If eligible, we will contact you to opt in or out.

We look forward to receiving your revised manuscript.

Kind regards,

Lars-Peter Kamolz, M.D., Ph.D., M.Sc.

Academic Editor

PLOS ONE

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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: (No Response)

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: Partly

**********

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

Reviewer #1: Yes

Reviewer #2: 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

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. 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: The authors addressed most of my comments and the current version is improved. I still have some comments, listed below (page numbers refer to the manuscript with track change).

p. 8 lines 131-138: Please explain how you matched groups (e.g., software).

Table 1: There is a mistake with the sample size of the matched group for released prisoners (n=1,286 and not n=1,548).

p. 8 line 134: Please define what is case-mix group of the index hospitalization.

Information is still needed on the variables: ADG and Ontario Mental Health and Addictions Scorecard and Evaluation Framework: are those variable summary scores? Continuous? What range? Etc. Please explain more clearly that primary care and ED use are variables (and how they were assessed).

Please avoid using too many abbreviations, the manuscript is quite hard to follow (see for example sentence p.9 line 156-160: 5 abbreviations).

Discussion: Please also discuss the effect size of the decrease in hospital readmission for prisoners recently released from prison. Maybe it is not clinically relevant.

Reviewer #2: You have decided to cut content regarding the 7-day period, since your focus

is on 30-day readmission rates and your regression analyses are focused on the 30-day period, and in

consideration of sample size issues. You must cut the 7-day data in Table 1 in post discharge section (primary care and emergency department care) and line 401.

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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.

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Reviewer #1: No

Reviewer #2: No

[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 to be viewed.]

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 us at figures@plos.org. Please note that Supporting Information files do not need this step.

Thirty-day readmission after medical-surgical hospitalization for people who experience imprisonment in Ontario, Canada: A retrospective cohort study

PONE-D-19-17979R2

Dear Dr. Kouyoumdjian,

We are pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it complies with all outstanding technical requirements.

Within one week, you will receive an e-mail containing information on the amendments required prior to publication. When all required modifications have been addressed, you will receive a formal acceptance letter and your manuscript will proceed to our production department and be scheduled for publication.

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With kind regards,

Lars-Peter Kamolz, M.D., Ph.D., M.Sc.

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

Reviewer #2: All comments have been addressed

**********

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

**********

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

Reviewer #1: Yes

Reviewer #2: 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

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. 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: (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 #1: No

Reviewer #2: No