PONE-D-22-13483Socioeconomic and ethnical disparity in coronary heart disease outcomes in Denmark and the effect of cardiac rehabilitation – a nationwide registry studyPLOS ONE

Dear Dr. Kjesbu,

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. Thank you for submitting your paper to PLOS One. Your study is interesting; please consider reviewer comments and submit a revised version of your manuscript.

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We look forward to receiving your revised manuscript.

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Salil Deo

Academic Editor

PLOS ONE

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Additional Editor Comments:

Please revise based on reviewer comments

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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: I Don't Know

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: The authors are to be commended for this analysis of the impact of Phase 2 Cardiac Rehabilitation on the care of patients with CVD in Denmark. "The data is the data"--and the authors appropriately note limitations inherent in their retrospective analysis utilizing 2 large, but imperfect and overlapping data bases.

Two items warrant attention:

Internal validity-The primary unit of analysis is the individual patient. It is probable that the individual CR programs differ substantially in their patient population (e.g. lower vs. higher SES), resources (some programs may be better resourced), and accessibility. It would be appropriate to analyze results from a program perspective, to see if there were disparities in process or outcome variable based upon program attended, and how this compared with individual patient characteristics. This may also provide actionable information regarding CR program improvement.

External validity-This study provides an analysis of patients in the single country of Denmark. A brief description of how these results may or may not be generalizable to other countries (i.e. particular characteristics of the Danish population and health system) would strength the discussion and conclusion.

Reviewer #2: Thanks for the opportunity to review the original article submitted by

Kjesbu et al. In this analysis of a large cohort of patients with myocardial infarction or coronary revascularization the Danish national registries, the investigators show that cardiac rehabilitation participation was overall low, and its components varied by patient demographic and economic position. The authors also found association between patient socioedemographics and major adverse cardiovascular event risk.

Abstract: well written overall.

Introduction

• Page 5/Line 8 – “American Association of Cardiology” should be “American College of Cardiology”

• Avoid the use of “cardiac patients”. Should be replaced with “patients with cardiovascular disease”

• Line 16 – “backgrounds”

Methods

- ICD10 codes usually has one letter and followed by number. The authors seem to have “D” in front of the ICD10 code. Are these Danish specific codes?

- Page 6/Line 16 – typo “DI219”

- Reference is needed for the Nordic procedure codes.

- The authors mention that reporting is mandatory for all CR patients to the DHRD, but in page 7/line 10-11, they report “In 2018-2019, the database covered 57% of all CR participants nationwide ranging between 25-75% in the different CR centers”. Can the authors explain the discrepancy?

- Can the authors explain what countries were defined as “Western”?

- Perhaps a better term than ethnicity used here is “nativity”.

Results

- Page 12/paragraph 1 should be the first paragraph in the results section.

Discussion

- Overall well written. No comments

Figures/Tables

- Consider adding variance around the bar graph estimates (95% Confidence intervals).

- Consider adding adjusted estimates with logistic regressions and 95% confidence interval for CR quality indicators.

- Consider adding % of patients achieving all CR quality indicators by nativity and education.

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Reviewer #1: Yes: Richard A Josephson, MS MD

Reviewer #2: Yes: Sadeer Al-Kindi

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PONE-D-22-13483R1Socioeconomic and ethnical disparity in coronary heart disease outcomes in Denmark and the effect of cardiac rehabilitation – a nationwide registry studyPLOS ONE

Dear Dr. Kjesbu,

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.

Please submit your revised manuscript by Oct 07 2022 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're 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.

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). You should upload this letter as a separate file labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Salil Deo

Academic Editor

PLOS ONE

Journal Requirements:

Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.

Additional Editor Comments:

Thank you for your changes. We would like to accept your manuscript after you consider replying to the point raised by reviewer #1. Once you submit a revised version with that point taken care of, we can accept your manuscript. Thank you.

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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: Partly

Reviewer #2: Yes

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

Reviewer #1: I Don't Know

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: 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

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: Please see prior comments. It is uncertain if the findings are due to variation in individual patients vs. variation in CR programs (i.e. programs serving lower SES patients may have less programmatic staffing or other resources). If this analysis is not part of the manuscript, then this limitation should be explicitly described.

Reviewer #2: Thank you for submitting the revised version.

The authorsn have addressed all my comments and the other reviewers comments

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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: Yes: Richard Josephson

Reviewer #2: Yes: Sadeer Al-Kindi

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[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.]

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

Socioeconomic and ethnical disparity in coronary heart disease outcomes in Denmark and the effect of cardiac rehabilitation – a nationwide registry study

PONE-D-22-13483R2

Dear Dr. Kjesbu,

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,

Salil Deo

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Thank you for submitting your work to PLOS One and addressing all comments made by reviewers.

Reviewers' comments: