PONE-D-22-18764Accuracy and repeatability of the Microsoft Azure Kinect for clinical measurement of motor functionPLOS ONE

Dear Dr. Otte,

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• Consider removing the information relating to the discontinued product
• Add Limits of Agreement in your analysis, as it would not only substantiate it further but also allow the reader a more informed decision on the agreement of the new device
• Include the limitations identified as part of your discussion

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PLOS ONE

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“The work was supported by the German Federal Ministry for Education and Science (BMBF, IFB 01EO1401), the Else Kröner-Fresenius Foundation (2018EKES09 80766157) and the Federal Joint Committee (G-BA, 01NVF19030). The Motognosis GmbH provided salaries for KO, SMM, TK and HMR.”

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“I have read the journal's policy and the authors of this manuscript have the following competing interests: SMM and KO are are shareholder of Motognosis GmbH and named as inventors on patent applications describing perceptive visual computing for tracking of motor dysfunction. HMR and TK are employed at Motognosis GmbH. All others report no conflict of interest.”

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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: Yes

Reviewer #2: Yes

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

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

Reviewer #1: 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: Dear Authors.

The work is very interesting and supports the results of others previously published with the Kinect One camera that this system is an easy solution for the evaluation of movement. The only problem is in relation to the sample size and the non-evaluation by age range.

The authors should explain the limitations of the sample and the age of the participants that prevent them from demonstrating the strength of the results.

Reviewer #2: This manuscript is well done and achieves its aim to assess the agreement between a marker system (the ‘gold’ standard Qualysis) against a newer marker-less system, and their respective reliability.

I have several observations which should be strongly considered before publication.

1. I am uncertain of the role of the K2 in this study. There is no convincing argument for including this device and comparing it to the others, especially when (as the authors state in at least 2 sentences) the K2 is no longer manufactured. If the K2 has never been compared to a 'gold standard' (which is implied on line 61,) it's a bit late!. Having these data also complicates the agreement and reliability analysis.

2. The statistical analysis is well done and comprehensive. However, when assessing the level of agreement between the systems (and hence the newer system’s (i.e. AK) validity against the ‘gold’ standard) the authors have opted for ICC (A,1). I strongly expect most readers will be also expecting to see the more familiar Bland and Altman plots to assess levels of agreement. Even though the ICC (A,1) does this, the visual effect of the Bland and Altman plots are important.

3. The second piece of advice surrounds the phrase ‘gold standard’. A more appropriate term, in this study using these systems, would be ‘clinical reference standard’. This means that it is the best available method, rather than the perfect method which the phrase ‘gold standard’ often implies.

4. Technical points. Figures 2 & 4 were unhelpful. Not sure what readers are supposed to see in this. This was even after I downloaded the tiff files.

Typographical errors

Line 57 spelling ‘these’

Line 57-62: it makes more sense to have the verbs in the past tense (i.e. extended, determined)

Line 68-69: This makes more sense to say that these were “exclusion criteria”

Line 76: “day- and artificial light“ ; delete the hypen

Line 114: insert ‘were terminated’

Line 303 “subtle disease-“ delete the hyphen

Line 307: it’s better to write more simply: “which is no longer manufactured”; I would repeat this version in the conclusion on line 328.

Line 325: The word ‘current’ here is actually a little confusing as at first glance it seems it should be ‘concurrent validation experiments’ (which I presume it is not). It would be better to write: “ In conclusion, the present validation experiments….”

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Reviewer #1: No

Reviewer #2: No

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Accuracy and Repeatability of the Microsoft Azure Kinect for clinical Measurement of motor Function

PONE-D-22-18764R1

Dear Dr. Otte,

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,

Theodoros M. Bampouras

Academic Editor

PLOS ONE

Additional Editor Comments: Please note the issues raised by Reviewer 2 re the image files and ability to play the files. Once in production, updated files may be required.

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: Yes

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

Reviewer #1: Yes

Reviewer #2: Yes

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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: Yes

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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: Yes

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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: Dear Authors

Thank you for responding appropriately to the suggestions made on the manuscript. I do not require any further clarification

Reviewer #2: All comments have been addressed.

Bland and Altman plots have been added and are now viewable.

However, the quality of supplementary files S1,2,3 is still very poor. I don't know if this will improve in the finalised published form.

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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: GRACIA CASTRO-LUNA

Reviewer #2: No

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