PONE-D-24-55854Device-based measurement of physical activity and sedentary behaviour after critical illness: A scoping reviewPLOS ONE

Dear Dr. Murphy,

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PLOS ONE

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Funding was provided by the Department for the Economy (DfE) Northern Ireland.”

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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: Partly

Reviewer #3: Yes

Reviewer #4: Yes

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

Reviewer #1: N/A

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: N/A

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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

Reviewer #3: Yes

Reviewer #4: 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

Reviewer #3: Yes

Reviewer #4: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: This is a precise scoping review of physical activity and sedentary behavior devices during and after critical illness and is promising for clinical application. The study methodology is transparent and reliable in that the protocol is publicly available and PRISMA-ScR compliant.

1. Practical suggestions regarding protocols

The authors emphasize the diversity of devices and data analysis methods in their discussion and conclusions. The need for standardized measurement protocols is an important point. Practical suggestions for researchers and clinicians are listed in Appendix S4. Still, if the main manuscript also mentions essential points, it will improve reader accessibility and complement the significance of this study.

2. Devices and data analysis methods specific to serious diseases

This scoping review is limited to studies during and after a serious illness. However, previous research on measuring physical activity and sedentary behavior has been conducted extensively on subjects other than those with serious illnesses. The research findings on subjects other than those with serious illness may contribute to establishing protocols for measurement devices and data analysis methods. If there are findings specific to serious illness regarding measurement devices and data analysis methods, highlighting these may enhance the novelty of the research. In addition, if there are any differences or similarities with existing protocols that target behaviors other than serious illness, these would also enhance the significance of this research.

Reviewer #2: I hope this letter finds you well. I had the opportunity to review your article titled, “Device-based measurement of physical activity and sedentary behavior after critical illness: A scoping review”, which was submitted to Plos One.

This article needs to be revised to fit the academic format.

Abstract

-. The research method written in the abstract refers to the research tool.

-. Please suggest research or analysis methods.

Introduction

-. Please change Background to introduction.

-. This reviewer does not fully recognize the necessity of this study.

-. Researchers need to logically explain ‘why’ they should conduct this research.

-. Please integrate the research objectives into one.

Method

-. Please explain ‘why’ you chose literature review to analyze the purpose of the study.

-. For example, it provides appropriate explanations of methods for literature research, such as frames, strategies, periods, and criteria.

-. The criteria for selecting prior research and data extraction were written very specifically, which is believed to increase the reliability of the study.

Results

-. The contents of Fig. 1 are not visible.

-. Please fix this by increasing the resolution so that the text can be seen.

-. Table 1, 2. Please organize and present the research materials by year.

-. The line spacing is irregular. The entire text needs to be edited.

-. I don't quite understand sentences 195-196.

-. The research results were written in detail by the researcher (level patterns, step counts, activity counts, sedentary behavior).

-. However, I question whether it has anything to do with the purpose of the study.

-. I don't understand why lines 233, 243, and 247 are spaced.

-. Overall, the research results are judged to have perfectly analyzed previous studies and to have been well organized by the researcher according to each criterion.

Discussion

-. Based on the research results, it is judged that the discussion was well conducted.

-. However, there is uncertainty as to whether the five objectives of the study were discussed.

-. The discussion needs to be organized according to the five research objectives.

-. Please modify Lines 472-475 to conform to the academic society format.

Conclusion

Please provide further explanation of the limitations of the study and suggestions for follow-up research.

-. I would like to see additional explanations regarding the academic and empirical applicability of this study.

Reviewer #3: Subject: Review of Manuscript PONE-D-24-55854

Dear Authors,

Thank you for the opportunity to review your manuscript titled "Device-based measurement of physical activity and sedentary behaviour after critical illness: A scoping review." I appreciate the effort that has gone into synthesizing the literature on this emerging research topic. The manuscript presents a well-structured scoping review and follows a rigorous methodological approach. Below, I provide my feedback regarding areas for improvement.

1. Technical Soundness and Data Support for Conclusions

The manuscript presents a technically sound scoping review on device-based measurements of physical activity and sedentary behavior in critically ill patients. The research rationale is well-explained, and the Arksey & O’Malley (2005) framework is appropriately employed for study selection. The review effectively synthesizes findings across 22 studies, covering different devices, data processing methods, and clinical outcomes.

However, a few key concerns should be addressed:

Lack of standardization in device-based data processing: The manuscript acknowledges heterogeneous data processing methods across studies but does not critically analyze the implications of such variations. A more detailed discussion on how these differences impact the comparability of findings would strengthen the manuscript.

Limited evidence on clinical impact: While the review effectively identifies device use trends, it would benefit from a more in-depth discussion on how these findings inform rehabilitation practices.

Underrepresentation of interventional studies: The manuscript notes that only one randomized control trial (RCT) was included. More discussion on the lack of high-quality trials and its implications for future research would be valuable.

2. Statistical Analysis and Data Reporting

The study does not perform a new statistical analysis but evaluates studies that have used various analytical methods.

Device comparisons lack uniform reporting: While Table 1 outlines device properties, the statistical reliability and error margins of different measurement methods should be discussed further.

The manuscript states that clinimetric properties (validity, reliability, responsiveness) were measured in only five studies but does not provide a systematic critique of these studies. A brief methodological critique of these validation studies would enhance the robustness of conclusions.

3. Data Availability and Compliance with PLOS Data Policy

The manuscript states that all relevant data are available within the manuscript and supporting materials, aligning with PLOS ONE’s open data policy. No concerns were identified regarding data accessibility.

4. Clarity and Language Quality

The manuscript is generally well-written in standard English, but minor grammatical errors and redundant phrasing could be improved. Some sentences are unnecessarily long, making them harder to follow. Examples:

Example 1 (Introduction, Lines 49-51):

"Many patients report challenges in returning to their usual activity levels."

Suggested revision: "Patients often struggle to regain pre-illness activity levels."

Example 2 (Results, Lines 312-314):

"Step counts were low, but gradually increased as patients transitioned from ICU to hospital ward to home."

Suggested revision: "Step counts were initially low but increased progressively from ICU to hospital discharge and home recovery."

Additionally, some sections lack coherence in citation formatting (see point 5).

5. Formatting and Referencing Issues

Citation inconsistencies:

The reference format appears inconsistent in certain places, e.g., citations [5] vs. [5, 6, 7]. Ensure that all references follow a consistent style.

Ensure full author names or initials are included in the reference list when required.

In-text citations:

Some references are missing the page number or DOI where necessary.

Table Formatting:

Table 1 (Device Comparison) is dense and difficult to read. Consider reorganizing it into clearer subsections (e.g., separate columns for wear time, activity parameters, and sampling frequency).

Table 2 (Measured Physical Activity and Sedentary Behavior) could benefit from bolded column headers for improved readability.

Overall Recommendation

The manuscript is technically sound, but needs minor revisions to improve clarity, reference consistency, and a more critical discussion of methodological issues in device-based measurement. Addressing these points will strengthen its contribution to rehabilitation research and critical care.

Reviewer #4: Overall Structure and Organization

The manuscript generally follows a logical structure for a scoping review, using the Arksey and O’Malley framework. The use of an inverted pyramid structure for presenting the review, with the most important information at the top, is helpful. The inclusion of a PRISMA flow diagram for study selection is also appropriate. However, there are areas within the sections that could be strengthened.

Specific Section Feedback

• Abstract: The abstract effectively summarizes the background, aims, methods, results, and conclusions of the review. However, the conclusion could be strengthened by explicitly stating the need for standardizing data processing and analysis protocols.

• Introduction/Background: This section introduces the problem of reduced physical activity after critical illness and the potential benefits of physical activity for rehabilitation. The background effectively establishes the importance of measuring physical activity in this population. However, the introduction could benefit from an earlier and clearer statement of the need for device-based measurement and the challenges associated with it.

• Aims and Objectives: The aims and objectives are clearly stated and well-defined. The questions outlined are relevant and directly addressed by the review.

• Methods: The methods section is comprehensive and outlines the search strategy, eligibility criteria, study selection process, and data extraction methods. The use of four electronic databases (Medline, ProQuest, Scopus, and CINAHL) is appropriate. The process of duplicate removal and study selection is clearly described. The use of Covidence as a screening tool is also noted. However, it is mentioned that the protocol was published in advance, but a statement indicating if there were deviations from the protocol is missing.

• Results: The results section clearly presents the study characteristics, device-based instruments used, parameters for physical activity, clinimetric properties, and associations with health-related outcomes. The use of tables and a flow diagram is very effective in presenting the data. However, there is some inconsistent formatting in the tables, as previously mentioned [see prior response and 142, 144, 147], where text appears to run into each other.

o Study Characteristics: This section provides a good overview of the included studies, but it could further emphasize the heterogeneity of the populations and study designs, which can limit generalizability.

o Device-based Instruments: The section provides a good overview of the devices used. It highlights that the Actiwatch Spectrum, ActivPAL3, and SenseWear armband were the most commonly used. The manuscript also highlights the inconsistent device placement (dominant/non-dominant limb). This variation should be highlighted as it can affect the results.

o Parameters of Physical Activity: This section identifies the variation in how physical activity and sedentary behavior were measured and reported (step counts, activity counts, time in activity, intensity of activity). This inconsistency is a major issue that needs to be addressed in the discussion.

o Clinimetric Properties: The lack of information regarding the reliability, responsiveness, and MCIDs is correctly identified. This lack of information needs to be addressed in the discussion as a major issue.

o Association with Health Parameters: The associations between physical activity and other health-related parameters are detailed, but some of the findings appear inconsistent across studies. The authors could potentially discuss why some studies show an association while others do not.

o Levels and Patterns of Physical Activity: This section effectively presents the low levels of physical activity and high levels of sedentary behavior in the ICU and post-discharge. The specific data included in Table 2 is useful to highlight the low activity levels throughout the trajectory of care.

• Discussion: The discussion section is thorough, summarizing key findings and highlighting the need for standardized protocols. The manuscript correctly highlights the inconsistencies in defining physical activity, sedentary behavior, intensity of activity, and thresholds for data analysis. The discussion also mentions the use of various sampling frequencies and the impact of epoch length. The authors could expand on the practical implications of these inconsistencies for clinicians and researchers. The importance of validating MET values for the critical care population is also emphasized. The discussion also highlights the potential impact of the use of low frequency filters on step counts. The discussion also mentions the need for future research and the need for an agreed protocol. The strengths and limitations of the review are not explicitly discussed in this section.

• Conclusion: The conclusion effectively summarizes the key findings of the review, reiterating the need for a standardized approach to device-based physical activity measurement in critical illness. However, the conclusion could further emphasize the need to validate MET values.

• Tables and Figures:

o Table 1: This table provides a comprehensive overview of the included studies, including devices used, wear time, and activity parameters. However, some of the data appears to be running into the adjacent cells of the table.

o Table 2: This table provides a summary of the measured physical activity and sedentary behavior. The information presented is thorough, however, there is an issue with the formatting.

o Figure 1: The PRISMA flow diagram is clear and accurately presents the study selection process.

Potential Errors to Address

• Inconsistent Reporting: The manuscript highlights the inconsistent reporting of various parameters related to the device and data processing, but this is not reflected in a limitation of the study, nor is it highlighted as a major issue.

Areas for Improvement

• Standardization: The manuscript should provide more concrete recommendations for standardization, such as suggesting specific epoch lengths, sampling frequencies, and MET thresholds for the critical care population.

• Clinimetric Properties: The authors should further emphasize the need for more research focused on validating device performance for critical care patients. The importance of establishing reliability, responsiveness, and MCIDs for physical activity and sedentary behavior in this population should be highlighted.

• MET Values: The manuscript should emphasize the need for the validation of appropriate MET values for this population, as previously discussed.

• Strengths and Limitations: The manuscript should explicitly state the strengths and limitations of the review process in the discussion section. This should include a discussion of the study designs of the included studies.

• Practical Implications: The authors could expand on the practical implications of their findings for both researchers and clinicians.

• Formatting: The formatting issues in the tables need to be addressed to ensure that the information is clearly displayed.

• Study Protocol Deviations: The authors should include a statement in the methods indicating if there were deviations from the published protocol.

Conclusion

The manuscript is a well-conducted scoping review that highlights the important issue of measuring physical activity in critically ill patients. By addressing the highlighted issues, particularly related to the standardization of data processing, establishing clinimetric properties, validating MET values for this population, and resolving formatting issues, the manuscript will be suitable for publication. The key areas to address would be the standardization of data processing and analysis, validation of MET values, and establishment of clinimetric properties for the critical care population.

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Reviewer #1: No

Reviewer #2: No

Reviewer #3: No

Reviewer #4: Yes:  Abdulmalik Alilu Abubakar

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Device-based measurement of physical activity and sedentary behaviour after critical illness: A scoping review

PONE-D-24-55854R1

Dear Dr. Murphy,

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,

Hidetaka Hamasaki

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: (No Response)

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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: (No Response)

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

Reviewer #1: N/A

Reviewer #2: (No Response)

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4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: (No Response)

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

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: (No Response)

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6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: The authors have made sufficient revisions in response to my comments. Thank you for your research, which is worthy of publication.

Reviewer #2: -. The content of this study was reviewed by four reviewers.

-. This reviewer believes that the researcher is fully aware of the reviewer's content.

-. It is also judged that the reviewer's content has been sufficiently revised.

-. In particular, it is judged that the introduction, methods, and discussion have been appropriately revised in response to the reviewer's revisions.

-. However, there are still parts of the paper format that are not compatible with the academic society format.

-. Please revise the paper format before final publication.

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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

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