Dear Dr. Wei,

Please submit your revised manuscript by Aug 23 2025 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.

• 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,

Jiawen Deng

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. Thank you for stating the following financial disclosure:

[The research work was funded by a grant from the National Natural Science Foundation of China (grant no. 81971772).]. 

Please state what role the funders took in the study.  If the funders had no role, please state: "The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript."

If this statement is not correct you must amend it as needed.

Please include this amended Role of Funder statement in your cover letter; we will change the online submission form on your behalf.

3. Thank you for stating the following in your manuscript:

[The research work was funded by a grant from the National Natural Science Foundation of China (grant no. 81971772). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.]

We note that you have provided funding information that is currently declared in your Funding Statement. However, funding information should not appear in the Acknowledgments section or other areas of your manuscript. We will only publish funding information present in the Funding Statement section of the online submission form.

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:

[The research work was funded by a grant from the National Natural Science Foundation of China (grant no. 81971772).]

Please include your amended statements within your cover letter; we will change the online submission form on your behalf.

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Does the manuscript provide a valid rationale for the proposed study, with clearly identified and justified research questions?

Reviewer #1: Yes

Reviewer #2: Yes

**********

2. Is the protocol technically sound and planned in a manner that will lead to a meaningful outcome and allow testing the stated hypotheses??>

Reviewer #1: Partly

Reviewer #2: No

**********

3. Is the methodology feasible and described in sufficient detail to allow the work to be replicable??>

Reviewer #1: Yes

Reviewer #2: Yes

**********

4. Have the authors described where all data underlying the findings will be made available when the study is complete??>

The PLOS Data policy

Reviewer #1: Yes

Reviewer #2: No

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English??>

Reviewer #1: Yes

Reviewer #2: Yes

**********

Please use the space provided to explain your answers to the questions above and, if applicable, provide comments about issues authors must address before this protocol can be accepted for publication. You may also include additional comments for the author, including concerns about research or publication ethics.

You may also provide optional suggestions and comments to authors that they might find helpful in planning their study.

Reviewer #1: Thank you for this protocol manuscript, which addresses an important topic. It is well written.

However, I do have some questions/feedback:

Pg 3: Financial disclosure statement missing

Pg 6 ln 120-121: ? does this include pre, peri and post op period? or just the perioperative period? Please clarify as earlier on you are presenting data from all periods?

Pg 6 ln 123: ?This is not an outcome. You need to define what outcomes you are specifically measuring - e.g. incidence of POD

Pg 6 ln 124-125: If you are looking for an association between the exposure and outcome, then why are you including cross sectional studies? Also, you discussed conflicts within literature between observational studies and RCT, yet you are excluding RCT - please justify your reasoning behind this.

Pg 6 ln 128-19: the use of insomnia symptoms or poor sleep quality are subjective measures, and thus if you are going to include them you need to clearly define what is meant by these. Also, how is poor sleep quality being identified? Using well defined criteria/diagnoses would provide a more objective and standard/consistent measure for sleep disorders.

Pg 6 ln 132: Also RCT according to your earlier criteria.

Pg 7 ln" 134: I am curious why Embase is being used, given its primary focus is on pharmaceuticals/drugs?

What about alternative databases, like CINAHL, especially as you indicate you are only including observational studies?

Pg 16 ln 194-199: what about the pre-existence of cognitive impairment/dementia, which is an important influencing factor, that can also impact on the diagnosis of POD?

Reviewer #2: Thank you for submitting this protocol on an important topic.

I have some concerns about the methodology you propose to study this topic. You indicate that your search will be limited to observational studies; however, you plan to search Cochrane Library, which indexes systematic reviews (CDSR) and randomized controlled trials (Central). This seems contradictory. Similarly, you justify your study by noting that since the publication of prior reviews there have been additional studies published which may contribute to further understanding; however, both of the additional studies cited appear to concern preoperative sleep disturbances, not postoperative.

Your search strategy also has issues that limit the methodological quality of the proposed review. You are missing potential synonyms such as emergence agitation and post surgical (with space). There are also unexplained differences in free-text search terms between different databases. Suggest also considering a search of PsycINFO, given the topic area.

**********

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

**********

[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.

Attachments

Attachment

Submitted filename: PONE-D-25-29095 fc.pdf

Dear Dr. Wei,

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 Nov 29 2025 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.

• 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 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,

Giovanni Giordano

Academic Editor

PLOS ONE

Journal Requirements:

If the reviewer comments include a recommendation to cite specific previously published works, please review and evaluate these publications to determine whether they are relevant and should be cited. There is no requirement to cite these works unless the editor has indicated otherwise. 

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.

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Does the manuscript provide a valid rationale for the proposed study, with clearly identified and justified research questions?

Reviewer #1: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

2. Is the protocol technically sound and planned in a manner that will lead to a meaningful outcome and allow testing the stated hypotheses??>

Reviewer #1: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

3. Is the methodology feasible and described in sufficient detail to allow the work to be replicable??>

Reviewer #1: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

4. Have the authors described where all data underlying the findings will be made available when the study is complete??>

The PLOS Data policy

Reviewer #1: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English??>

Reviewer #1: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

Please use the space provided to explain your answers to the questions above and, if applicable, provide comments about issues authors must address before this protocol can be accepted for publication. You may also include additional comments for the author, including concerns about research or publication ethics.

You may also provide optional suggestions and comments to authors that they might find helpful in planning their study.

Reviewer #1: Thank you for taking into consideration the reviewers comments, which you have incorporated into your revised manuscript. There are still a few questions I still have, for your review.

Reviewer #3: The revised manuscript, “The relationship between sleep disorders and postoperative delirium in adult patients: protocol for an updated systematic review and meta-analysis,” represents a substantial improvement over the previous version.

The authors have carefully addressed the reviewers’ main concerns, providing clearer methodological justifications, improving the definition of key variables, and aligning the study design with PRISMA-P standards.

The protocol is now methodologically sound, well structured, and scientifically relevant, especially given the ongoing clinical interest in postoperative delirium and perioperative sleep disorders.

Overall, the paper is suitable for publication after minor corrections.

The study aims and PECOS framework are now clearly described. It might still be helpful to slightly rephrase the objective sentence in the Objectives and outcomes section for smoother readability (e.g., “The objective of this review is to determine whether perioperative sleep disorders are associated with an increased risk of postoperative delirium in adult surgical patients.”).

The authors have adequately justified the exclusion of cross-sectional studies and randomized trials. However, the Data synthesis section could benefit from a brief statement explaining how discrepancies between subjective and objective measures of sleep quality will be handled during analysis, to further strengthen methodological clarity.

The Discussion provides a reasonable summary, though a few sentences could be edited for conciseness. In particular, lines describing the implications for “patients with POD making better health decisions” could be rephrased to focus on how clinicians might use these findings to improve perioperative management and patient outcomes.

The manuscript would benefit from a light linguistic edit to correct minor grammatical inconsistencies (e.g., missing articles, plural forms, and slight redundancies). This is not substantial but would enhance overall readability.

Ensure consistent use of tense (present vs. future) throughout the Methods section and uniform spacing between subsections.

The reference list is comprehensive and current.

Reviewer #4: Dear Editors and Authors,

I thank you for the opportunity to review the manuscript PONE-D-25-29095R1 titled “The relationship between sleep disorders and postoperative delirium in adult patients: protocol for an updated systematic review and meta-analysis”.

I have carefully reviewed the revised version of the manuscript, the supplemental files, and the detailed responses to the reviewers’ comments. Overall, the authors have made substantial improvements in addressing the concerns raised during the initial review.

Positive aspects:

• The clarification regarding the inclusion of pre- and post-operative periods in the assessment of sleep disorders adds important context to the study design.

• The refinement of outcome definitions, particularly specifying the incidence of POD, enhances the focus and clarity of the analysis.

• The exclusion of cross-sectional studies and the rationale for not including RCTs are now well justified by the authors.

• The inclusion of additional databases such as CINAHL and PsycINFO, strengthens the comprehensiveness of the systematic search strategy.

• Finally, the revision of inclusion criteria to consider cognitive impairment as a potential confounding factor appropriately addresses an important variable influencing POD diagnosis.

Suggestions for further improvement:

• The addition of the keyword "emergence agitation" and “post surgical” in the search strings of the various databases is a positive step. In the Search Strategy paragraph, I recommend also including the term "post surgical," as suggested by Reviewer 2.

• Furthermore, I believe it would be useful to specify the use of Boolean operators (AND, OR) in the Search Strategy paragraph as well, in order to clarify how the different groups of keywords are connected in the search.

Minor grammatical and syntactic improvements:

• Line 33: “Pubmed” → “PubMed”

• Line 39: “used” → “conducted”

• Line 68: “a” after “is,” not before (typographical error)

• Line 86: “had investigated association” → “had investigated the association” (add “the”)

• Line 106: “is summary and analysis” → “is a summary and analysis” (missing article)

• Line 112: “The sole objective of this is to determine” → “The sole objective of this study is to determine” (add “study” for clarity)

• Line 114: “Compares” → In the PECOS model, C stands for “Comparator,” not “Compares”

• Line 132: “association of sleep disorders and the risk of POD” → “association between sleep disorders and the risk of POD”

• Lines 132-133: “Included participants diagnosed with sleep disorders and no sleep disorders.” → “Studies including participants with and without diagnosed sleep disorders.”

• Line 133: “subjectively or objectively diagnostic criteria” → “subjective or objective diagnostic criteria”

• Line 143: Remove comma after “2025”

• Line 155: “in The Endnote X9 software reference manager” → “in EndNote X9 reference management software”

• Line 169: “contacted for obtain the relevant information” → “contacted to obtain the relevant information”

• Line 173: Avoid repeating “scale” twice in “The Newcastle Ottawa Scale (NOS) assessment scale will be used…”

• Line 174: “researches” → “studies” (in scientific English “research” is uncountable, use “studies or research studies” in plural)

• Line 192: “otherwise narrative synthesis will be taken” → “otherwise a narrative synthesis will be carried out”

• Lines 197: “was evaluated” → Should be future tense: “will be evaluated”

• Lines 217-219: “Sleep disorders are prevalent and common during the surgery” → I think that “during the perioperative period” is more appropriate

• Lines 219-220: “association of sleep disorders and the risk of POD” → “association between sleep disorders and the risk of POD”

• Lines 222-223: “patients with POD may take into consideration the sleep disorders to make better health decisions” → “patients with POD may take sleep disorders into account when making health decisions”

• Line 225: “higher risk of publication” → Add “bias”: “higher risk of publication bias”

• Lines 227: “should be used to explore the source of heterogeneity” → “will be used to explore sources of heterogeneity”

Overall recommendation:

The manuscript shows substantial enhancement and better alignment with PLOS ONE’s publication criteria. Pending minor revisions as outlined, I believe it merits acceptance for publication. The authors are encouraged to refine the indicated sections to further improve transparency and reproducibility.

I thank the authors for their commitment to improving the manuscript and remain available for any further review if needed.

Best regards,

Gaetano Gazzè

**********

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 #3: No

Reviewer #4: Yes:  Gaetano Gazzè

**********

[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

Attachments

Attachment

Submitted filename: PONE-D-25-29095_R1_fc.pdf

The relationship between sleep disorders and postoperative delirium in adult patients: protocol for an updated systematic review and meta-analysis

PONE-D-25-29095R2

Dear Dr. Wei,

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 will be generated when your article is formally accepted. Please note, if your institution has a publishing partnership with PLOS and your article meets the relevant criteria, all or part of your publication costs will be covered. Please make sure your user information is up-to-date by logging into Editorial Manager at Editorial Manager®  and clicking the ‘Update My Information' link at the top of the page. For questions related to billing, please contact billing support .

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,

Giovanni Giordano

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Does the manuscript provide a valid rationale for the proposed study, with clearly identified and justified research questions?

Reviewer #4: Yes

**********

2. Is the protocol technically sound and planned in a manner that will lead to a meaningful outcome and allow testing the stated hypotheses??>

Reviewer #4: Yes

**********

3. Is the methodology feasible and described in sufficient detail to allow the work to be replicable??>

Reviewer #4: Yes

**********

4. Have the authors described where all data underlying the findings will be made available when the study is complete??>

The PLOS Data policy

Reviewer #4: No

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English??>

Reviewer #4: Yes

**********

Please use the space provided to explain your answers to the questions above and, if applicable, provide comments about issues authors must address before this protocol can be accepted for publication. You may also include additional comments for the author, including concerns about research or publication ethics.

You may also provide optional suggestions and comments to authors that they might find helpful in planning their study.

Reviewer #4: Good morning,

I believe the protocol has now reached a solid and satisfactory standard. I wish you the best of luck with the remaining work to complete the study.

Kind regards,

Gaetano Gazzè

**********

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 #4: Yes:  Gaetano Gazzè

**********