Correlates of variability in endurance shuttle walk test time in patients with chronic obstructive pulmonary disease

Anouk A. F. Stoffels; Bram van den Borst; Jeannette B. Peters; Mariska P. M. Klaassen; Hanneke A. C. van Helvoort; Roy Meys; Peter Klijn; Chris Burtin; Frits M. E. Franssen; Alex J. van ‘t Hul; Martijn A. Spruit; Hieronymus W. H. van Hees; on behalf of the BASES consortium

doi:10.1371/journal.pone.0249786

Peer Review History

Original SubmissionOctober 16, 2020
12 Feb 2021 Decision Letter - Chris Harnish, Editor PONE-D-20-32526 Correlates of variability in endurance shuttle walk test time in patients with chronic obstructive pulmonary disease PLOS ONE Dear Dr. Stoffels, Thank you for submitting your manuscript to PLOS ONE and for your patience on this review. 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. To facilitate your revisions, I have outline some key areas to address, in addition to our reviewers. These include: Following your purpose statement in the intro, add clearly identified hypotheses. Please reword the conclusion statements for the abstract and paper to the past tense. Be sure to proof read for consistent use of formatting. I agree with the reviewer. A flow chart of some type would aid for the inclusion/exclusion section. Likewise, please include effect sizes. Suggestion: Line 231, change high variability (vague) to ESWT Tlim highly variable As noted above, much of the conclusion is written in present tense. Please submit your revised manuscript by Mar 29 2021 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: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols We look forward to receiving your revised manuscript. Kind regards, Chris Harnish, PhD Academic Editor PLOS ONE Journal Requirements: When submitting your revision, we need you to address these additional requirements. 1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf 2. In the methods section please provide a reference to the main study from which the secondary analysis was performed from. 3. We note that the grant information you provided in the ‘Funding Information’ and ‘Financial Disclosure’ sections do not match. When you resubmit, please ensure that you provide the correct grant numbers for the awards you received for your study in the ‘Funding Information’ section. 4. Thank you for stating the following in the Competing Interests section: "Dr. F.M.E. Franssen is supported by grants and personal fees from AstraZeneca, personal fees from Boehringer Ingelheim, personal fees from Chiesi, personal fees from GlaxoSmithKline, grants and personal fees from Novartis, personal fees from TEVA, outside the submitted work. Dr. B. van den Borst is supported by personal lecture fees from AstraZeneca and Boehringer Ingelheim bv. A.A.F. Stoffels, R. Meys, H.W.H. van Hees, P. Klijn, C. Burtin, M.A. Spruit, H.A.C. van Helvoort, J.B. Peters, M.P.M. Klaassen and A.J. van ‘t Hul declare that they do not have a conflict of interest." Please confirm that this does not alter your adherence to all PLOS ONE policies on sharing data and materials, by including the following statement: "This does not alter our adherence to PLOS ONE policies on sharing data and materials.” (as detailed online in our guide for authors http://journals.plos.org/plosone/s/competing-interests). If there are restrictions on sharing of data and/or materials, please state these. Please note that we cannot proceed with consideration of your article until this information has been declared. Please include your updated Competing Interests statement in your cover letter; we will change the online submission form on your behalf. Please know it is PLOS ONE policy for corresponding authors to declare, on behalf of all authors, all potential competing interests for the purposes of transparency. PLOS defines a competing interest as anything that interferes with, or could reasonably be perceived as interfering with, the full and objective presentation, peer review, editorial decision-making, or publication of research or non-research articles submitted to one of the journals. Competing interests can be financial or non-financial, professional, or personal. Competing interests can arise in relationship to an organization or another person. Please follow this link to our website for more details on competing interests: http://journals.plos.org/plosone/s/competing-interests 5. One of the noted authors is a group or consortium [BASES consortium]. In addition to naming the author group, please list the individual authors and affiliations within this group in the acknowledgments section of your manuscript. Please also indicate clearly a lead author for this group along with a contact email address. 6. Please include captions for your Supporting Information files at the end of your manuscript, and update any in-text citations to match accordingly. Please see our Supporting Information guidelines for more information: http://journals.plos.org/plosone/s/supporting-information. [Note: HTML markup is below. Please do not edit.] 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 ******** 2. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes ****** 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 ****** 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 ****** 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: General Comments The reviewer would like to thank the authors for taking the time to produce a well described and written study. Please see specific comments below. Abstract Line 28: Suggest changing to not completely understood. Line 32: If there is room, please include inclusion/exclusion criterion Line 35: Please add statistical analyses used. Line 43: suggest moving to past tense: Secondly, these results demonstrated … Introduction Overall the introduction is well defined and written. Line 67: Like within the abstract, suggest changing to not completely understood. Methods Line 114: nine meters, instead of nine meter. (same with 10 meters). Line 124: percentage of predicted…please be more specific of the predicted metric. Line 127: Paragraphs starting here are indented while all others beforehand are not. Please revise. Line 124-126: Suggest having a separate paragraph prior to test that describe inclusion and exclusion criterion. Further a flow chart may aid the reader in understanding how the sample was obtained. Statistical analyses: Suggest including an effect size index analysis for significant difference findings as this will give further context of the magnitude of these potential differences. Results Well described Discussion Overall well done . ****** 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: Yes:** Garrett Scott Bullock [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. https://doi.org/10.1371/journal.pone.0249786.r001
Revision 1
19 Mar 2021 Author Response Response to reviewers We would like to thank the editor and the reviewer for their constructive comments and giving us the opportunity to revise our manuscript. We provided a point-by point reply below and adapted the manuscript accordingly. The reported page and line numbers correspond to the manuscript with track changes (view: all markup). Comments editor C1. Following your purpose statement in the intro, add clearly identified hypotheses. R1. We have added our hypothesis after the aim in the introduction: “A priori, we hypothesized that parameters of pulmonary function and physical performance are independent determinants of ESWT Tlim and can partly explain the high variability of ESWT Tlim in patients with COPD”, see page 6, lines 102-105. C2. Please reword the conclusion statements for the abstract and paper to the past tense. R2. The conclusion statement in the abstract and paper has been changed to the past tense, see page 4, lines 54-60 (abstract) and pages 20-21, lines 401-408 (paper). C3. Be sure to proof read for consistent use of formatting. R3. We have proof read the article and made some changes to obtain a consistent format of the manuscript. Changes are marked in the tracked changes version of the revised manuscript. C4. I agree with the reviewer. A flow chart of some type would aid for the inclusion/exclusion section. R4. We agree with the reviewer and made a flow chart that shows how the number of patients used for the analyses was reached, see figure 1. C5. Likewise, please include effect sizes. R5. Thank you for your suggestion. We assume that the reviewer suggests to include a column in tabel1, 2 and S2 with standardized effect sizes on differences of the parameters described. We have discussed this topic with our statistician (dr. A.R.T. Donders). In our opinion, the interpretation of the magnitude of differences will not be improved by including such effect size numbers, because 1) effect sizes of 2 or 3 comparisons per parameter are difficult to reflect in one number and 2) both non-parametric and parametric testing was applied, which affects the interpretation of effect sizes. So, we think that the raw data as presented in table 1,2 and S2 is the most appropriate way to show the magnitude of the differences across the three groups. Nevertheless, as we reviewed table 1, we noted that the difference in mMRC score may not be clear to the readers. In the revised manuscript we therefore expressed the mean mMRC score in the text as well ‘Patients in group 3 were younger (59.4 ± 8.6 years) than patients in group 2 (62.4 ± 7.2 years, p=0.021). The severity of dyspnea sensation, as reflected by the mMRC score, was lower in patients from group 3 (median 2(1-3) and mean 1.8±1.2) than in patients from group 2 (median 2(1-3) and mean 2.2±1.2, p=0.006).’., see page 11, lines 214-216. C6. Suggestion: Line 231, change high variability (vague) to ESWT Tlim highly variable R6. Thank you for this suggestion, it has been changed to ‘ESWT Tlim highly variable’ in the manuscript on page 16, line 297. C7. As noted above, much of the conclusion is written in present tense. R7. The conclusion has been rewritten in the past tense, see pages 20-21, lines 401-408. ‘This study confirmed a large interindividual variability in ESWT Tlim in patients with COPD, as only half of the patients reached an ESWT Tlim within the desired duration of 3-8 minutes. Our data showed that next to maximal ISWT speed, other ISWT performance measures as well as clinically available measures of pulmonary function, physical capacity and physical activity were independent determinants of ESWT Tlim. Nevertheless, these determinants could only explain ~30% of its variability. Therefore, future studies are needed to establish whether these and additional factors can be used to better adjust individual ESWT pace in order to reduce ESWT Tlim variability.’ C8. Please ensure that your manuscript meets PLOS ONE’s style requirements, including those for file naming. The PLOS ONE style templates can be found at: https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf R8. The manuscript has been checked and adapted to the PLOS ONE requirements. C9. In the methods section please provide a reference to the main study from which the secondary analysis was performed form. R9. The data is obtained as part of standard care during baseline assessment of a pulmonary rehabilitation program in our center. There is no main study from which this is a secondary analysis. However, as we understand the confusion, the term ‘standard care’ has been added to the methods section, ‘The data was collected during baseline assessment as part of standard care of the PR program.’ see page 7, lines 112-113. C10. We note that the grant information you provided in the ‘Funding information’ and ‘Financial Disclosure’ sections do not match. When you resubmit, please ensure that you provide the correct grant numbers for the awards you received for the study in the ‘Funding Information’ section. R10. Thank you for noticing. The financial disclosure should be changed to ‘The BASES consortium is financially supported by the Lung Foundation, the Netherlands (#5.1.18.232).’ as mentioned in the cover letter. The mentioned grants of F. Franssen and B. van den Borst have no influence and are unrelated to the submitted article. Furthermore, this information has already been mentioned in the ‘conflicts of interests’ section in the manuscript. We apologize for the confusion and our mistake. As we cannot change the financial disclosure section ourselves, we would appreciate if you can change this for us. If you have further questions regarding the funding, please contact us. Initially, we did not provide a name for recipient of the grant of the Lung foundation as this has been provided to the BASES consortium. We have changed this to Martijn Spruit as he is the lead author of the BASES consortium. C11. Thank you for stating the following in the Competing Interests section: "Dr. F.M.E. Franssen is supported by grants and personal fees from AstraZeneca, personal fees from Boehringer Ingelheim, personal fees from Chiesi, personal fees from GlaxoSmithKline, grants and personal fees from Novartis, personal fees from TEVA, outside the submitted work. Dr. B. van den Borst is supported by personal lecture fees from AstraZeneca and Boehringer Ingelheim bv. A.A.F. Stoffels, R. Meys, H.W.H. van Hees, P. Klijn, C. Burtin, M.A. Spruit, H.A.C. van Helvoort, J.B. Peters, M.P.M. Klaassen and A.J. van ‘t Hul declare that they do not have a conflict of interest." Please confirm that this does not alter your adherence to all PLOS ONE policies on sharing data and materials, by including the following statement: "This does not alter our adherence to PLOS ONE policies on sharing data and materials.” (as detailed online in our guide for authors http://journals.plos.org/plosone/s/competing-interests). If there are restrictions on sharing of data and/or materials, please state these. Please note that we cannot proceed with consideration of your article until this information has been declared. Please include your updated Competing Interests statement in your cover letter; we will change the online submission form on your behalf. R11. We have added the statement to the ‘conflicts of interest’ section, see page 23, line 439. C12. One of the noted authors is a group or consortium [BASES consortium]. In addition to naming the author group, please list the individual authors and affiliations within this group in the acknowledgements section of your manuscript. Please also indicate clearly a lead author for this group along with a contact email address. R12. We have listed the individual authors of the BASES consortium to the acknowledgements section, including the affiliations, see page 22, lines 415-421. ‘The BASES consortium consists of M.A. Spruit (CIRO, lead author, e-mail: martijnspruit@ciro-horn.nl), A.A.F. Stoffels (Radboudumc), R. Meys (CIRO), P. Klijn (Merem), H.W.H. van Hees (Radboudumc), C. Burtin (Hasselt University), F.M.E. Franssen (CIRO), B. van den Borst (Radboudumc), J. De Brandt (Hasselt University), M.J.H. Sillen (CIRO), E.F.M. Wouters (CIRO), E. bij de Vaate (Merem), F.N. Schleich (CHU Sart-Tilman Liege), M. Hayot (University of Montpellier – Montpellier CHU), P. Pomiès (University of Montpellier – Montpellier CHU), W. Derave (Ghent University) and I. Everaert (Ghent University).’ C13. Please include captions for you Supporting Information files at the end of your manuscript, and update any in-text citations to match accordingly. Please see our Supporting Information Guidelines for more information: http://journals.plos.org/plosone/s/supporting-information. R13. We have added a Supporting Information Caption to the manuscript, see page 23, lines 441-445. ‘S1 Table. ESWT parameters for the whole group and subgroups. S2 Table. Univariate linear regression models for the clinical parameters and ESWT Tlim. S3 Table. Univariate linear regression models for the ISWT parameters and ESWT Tlim S4 Table. Multivariate linear regression analysis to predict ESWT Tlim.’ Reviewer 1 C1. Abstract: line 28: Suggest changing to not completely understood. R1. We agree with this suggestion and it has been changed to ‘.. factors determining ESWT Tlim are not completely understood.’ in the manuscript on page 3, line 35. C2. Abstract: line 32: If there is room, please include inclusion/exclusion criterion R2. The inclusion criteria have been added to the abstract: ‘Inclusion criteria were: diagnosis of COPD and complete data availability regarding ESWT and ISWT.’ see page 3, lines 39-40. C3. Abstract: line 35: Please add statistical analyses used. R3. Thank you for this suggestion. We understand the additional value of describing the statistical analyses in the abstract. However, the maximal number of words does not allow us to describe the statistical analyses clearly and complete. Therefore, we have chosen to leave the statistical analysis out of the abstract. C4. Abstract: line 43: suggest moving to past tense: Secondly, these results demonstrated.. R4. Thank you for the suggestion, the conclusion has been changed to the past tense, see page 4, lines 54-60. ‘Conclusion: This study reported a large variability in ESWT Tlim in COPD patients. Secondly, these results demonstrated that next to maximal ISWT speed, other ISWT performance measures as well as clinical measures of pulmonary function, physical capacity and physical activity were independent determinants of ESWT Tlim. Nevertheless, as these determinants only explained ~30% of the variability, future studies are needed to establish whether additional factors can be used to better adjust individual ESWT pace in order to reduce ESWT Tlim variability.’ C5. Introduction: Overall the introduction is well defined and written. Line 67: Like within the abstract, suggest changing to not completely understood. R5. Thank you for the suggestion, this was adjusted in the manuscript on page 5, line 84. C6. Methods: line 114: nine meters, instead of nine meter. (same with 10 meters). R6. Thank you for the suggestion, it has been changed in the manuscript to ‘The ISWT required the patients to walk around two markers set nine meters apart (10 meters course) …’ on page 8, lines 146-147. C7. Methods: line 124: percentage of predicted…please be more specific of the predicted metric. R7. We have added ‘in meters’ after ISWT distance to clarify the used metric ‘the ISWT distance in meters was calculated as percentage of predicted’, see page 9, lines 155-156. C8. Methods: line 127: Paragraphs starting here are indented while all others beforehand are not. Please revise. R8. We have indented all paragraphs. C9. Methods: line 124-126: Suggest having a separate paragraph prior to test that describe inclusion and exclusion criterion. Further a flow chart may aid the reader in understanding how the sample was obtained. R9. We agree that this will help the reader to understand how the sample was obtained, so we added a flowchart with in- and exclusion criteria to the manuscript, see figure 1. C10. Methods: statistical analyses: Suggest including an effect size index analysis for significant difference findings as this will give further context of the magnitude of these potential differences. R10. Thank you for your suggestion. If we understand correctly, you suggest to include a column in tabel1, 2 and S2 with standardized effect sizes on differences of the parameters described in those tables. We have discussed this topic with our statistician (dr. A.R.T. Donders). We think that the interpretation of such effect size is hampered, because 1) effect sizes of 2 or 3 comparisons per parameter are difficult to reflect in one number and 2) both non-parametric and parametric testing was applied. So, in our opinion the raw data as presented in table 1,2 and S2 is the most appropriate way to show the magnitude of the differences across the three groups. Nevertheless, as we reviewed table 1, we noted that the difference in mMRC score may not be clear to the readers. In the revised manuscript we therefore expressed the mean mMRC score in the text as well ‘Patients in group 3 were younger (59.4 ± 8.6 years) than patients in group 2 (62.4 ± 7.2 years, p=0.021). The severity of dyspnea sensation, as reflected by the mMRC score, was lower in patients from group 3 (median 2(1-3) and mean 1.8±1.2) than in patients from group 2 (median 2(1-3) and mean 2.2±1.2, p=0.006).’., see page 11, lines 214-216. C11. Results: well described. C11. Thank you! C12. Discussion: overall well done. C12. Thank you very much for your constructive comments! Attachments Attachment Submitted filename: Response to reviewers.docx* https://doi.org/10.1371/journal.pone.0249786.r002
25 Mar 2021 Decision Letter - Chris Harnish, Editor Correlates of variability in endurance shuttle walk test time in patients with chronic obstructive pulmonary disease PONE-D-20-32526R1 Dear Dr. Stoffels, 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, Chris Harnish, PhD 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 ******** 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 ****** 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: The addressed the reviewer comments. I have no other editorial comments. I commend the authors on their work. ****** 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:** Garrett Scott Bullock https://doi.org/10.1371/journal.pone.0249786.r003
Formally Accepted
12 Apr 2021 Acceptance Letter - Chris Harnish, Editor PONE-D-20-32526R1 Correlates of variability in endurance shuttle walk test time in patients with chronic obstructive pulmonary disease Dear Dr. Stoffels: 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. Chris Harnish Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0249786.r004

Open letter on the publication of peer review reports

PLOS recognizes the benefits of transparency in the peer review process. Therefore, we enable the publication of all of the content of peer review and author responses alongside final, published articles. Reviewers remain anonymous, unless they choose to reveal their names.

We encourage other journals to join us in this initiative. We hope that our action inspires the community, including researchers, research funders, and research institutions, to recognize the benefits of published peer review reports for all parts of the research system.

Learn more at ASAPbio .