Does Blast Mild Traumatic Brain Injury Have an Impact on PTSD Severity? A Systematic Review and Meta-Analysis

Round 1

Reviewer 1 Report

The authors present a well-conceived and clearly written manuscript on the relationship of PTSD to mild TBI from blast injury. Overall it is very well done and an important consideration to the field of TBI.

Author Response

Comment: The authors present a well-conceived and clearly written manuscript on the relationship of PTSD to mild TBI from blast injury. Overall, it is very well done and an important consideration to the field of TBI.

Author response: Thank you for your kind words and thank you for taking the time to review our manuscript.

Reviewer 2 Report

Thank you for your interesting submission.

Introduction

- You discuss the grading of TBI severity as related to loss of consciousness, post-traumatic amnesia, and GCS. I recommend citing your source for this whether it is from the VA/DoD clinical practice guidelines or the Mayo Clinic classification system

-  "protean of" does not make sense. Please use a different word for ease of reading such as plethora.

- you discuss PCL in terms of DSM-IV with 3 distinct versions in your introduction and methods. I understand it is possible no papers were included that used PCL-5 but it may be helpful to readers using the DSM-V to briefly mention the 3 categories used in your systematic review are no longer used.

Results

- Figure 1 does not appear to be included for review

- any additional corrections when using unpaired t-test? For example, Welch's correction for unequal variances?

Discussion

- you discussed a limitation being the use of studies from the last 10 years and increasing the scope of review given timing of military conflicts. Why not do that for this study?

- good discussion on future directions and cautious in conclusions given number of papers and heterogeneity

Author Response

Comment: You discuss the grading of TBI severity as related to loss of consciousness, post-traumatic amnesia, and GCS. I recommend citing your source for this whether it is from the VA/DoD clinical practice guidelines or the Mayo Clinic classification system.

Author response: Thank you for this suggestion. We have added a reference to the Mayo clinic classification.

 

Comment:  "protean of" does not make sense. Please use a different word for ease of reading such as plethora.

Author response: Apologies. It is now amended.

 

Comment: you discuss PCL in terms of DSM-IV with 3 distinct versions in your introduction and methods. I understand it is possible no papers were included that used PCL-5 but it may be helpful to readers using the DSM-V to briefly mention the 3 categories used in your systematic review are no longer used.

Author response: Thank you. We have added this in the Introduction, Lines 89-94.

 

Comment: Figure 1 does not appear to be included for review.

Author comment: Apologies, this is now included.

 

Comment: any additional corrections when using unpaired t-test? For example, Welch's correction for unequal variances?

Author response: No we did not use additional corrections as we used means.

 

Comment: you discussed a limitation being the use of studies from the last 10 years and increasing the scope of review given timing of military conflicts. Why not do that for this study?

Author response: Although this is a limitation as discussed increasing the time and scope of the study would introduce more bias since the diagnosis of mTBI, which is the signature injury in the military has been difficult with improved methods being developed in the last 10 years. Hence, studies in the last 10 years should contain publications with better quality mTBI diagnosis and hence any insights would be more reliable.

 

Comment: good discussion on future directions and cautious in conclusions given number of papers and heterogeneity

Author response: Thank you.

Reviewer 3 Report

This systematic review and meta-analysis provides the influence of blast induced mTBI on PTSD symptom severity among military personnel.

Lines 20, 33: Change "compared to" to "compared with"

Lines 37-40. Is this your definition for mTBI? or did you get this from another source? if so, a reference is needed.

Line 87: Change ""...groups to..." to "...groups with..."

The introduction provides a comprehensive background supporting the aim of the review.

The discussion section is also clearly written and very comprehensive.

The authors conclusions are follow from the information presented in the discussion section.  

Author Response

Comment: Lines 20, 33: Change "compared to" to "compared with"

Author response: Amended.

 

Comment: Lines 37-40. Is this your definition for mTBI? or did you get this from another source? if so, a reference is needed.

Author response: Reference has been added in response to another reviewer comment also.

 

Comment: Line 87: Change ""...groups to..." to "...groups with..."

Author response: Amended, now line 99.

 

Comments: The introduction provides a comprehensive background supporting the aim of the review. The discussion section is also clearly written and very comprehensive. The authors conclusions are follow from the information presented in the discussion section.  

Author response: Thank you and thank you for taking the time to review our manuscript.

Reviewer 4 Report

Thank you for submitting this systematic review. 

As you will note for the comments I have made on your actual paper, one important figure and one table are apparently missing from your submission. I believe that these are crucial to the understanding of your paper.

The methods and results sections are reasonably well explained, but your discussion requires extensive clarification as I have pointed out.

Since you have noted such extensive limitations I wonder if indeed you should repeat this study, applying some of the additional factors you outline.

Comments for author File: Comments.pdf

Author Response

Comment: As you will note for the comments I have made on your actual paper, one important figure and one table are apparently missing from your submission. I believe that these are crucial to the understanding of your paper.

Author response: Apologies for our oversight. Figure 1 and Table 3 are now included.

 

Comment: The methods and results sections are reasonably well explained, but your discussion requires extensive clarification as I have pointed out.

Author response: All of the changes suggested in the pdf version of our document from the reviewer has been addressed in the revised version (all tracked).

 

Comment: Since you have noted such extensive limitations I wonder if indeed you should repeat this study, applying some of the additional factors you outline.

Author response: The trouble with that is that we will have a new set of limitations since there is always some limitations in a systematic review. Hence, we feel that this would not be useful. We merely pointed these out in the review so that the reader is aware.

Round 2

Reviewer 2 Report

Thank you for addressing my previous suggestions. The only change I would make from here are the following:

Line 81: it says '(or DSM-5)' while it should reflect the fact the PCL-5 is the scale that corresponds to DMS-5 criteria for PTSD. I suggest rephrasing this to say '(for DSM-5)'

Line 85: it says '(most similar to DSM-5)'. I would either change it to '(most similar to DSM-5 criteria)' or '(most similar to current PCL-5)'.

Author Response

Comment: You discuss the grading of TBI severity as related to loss of consciousness, post-traumatic amnesia, and GCS. I recommend citing your source for this whether it is from the VA/DoD clinical practice guidelines or the Mayo Clinic classification system.

Author response: Thank you for this suggestion. We have added a reference to the Mayo clinic classification.

 

Comment:  "protean of" does not make sense. Please use a different word for ease of reading such as plethora.

Author response: Apologies. It is now amended.

 

Comment: you discuss PCL in terms of DSM-IV with 3 distinct versions in your introduction and methods. I understand it is possible no papers were included that used PCL-5 but it may be helpful to readers using the DSM-V to briefly mention the 3 categories used in your systematic review are no longer used.

Author response: Thank you. We have added this in the Introduction, Lines 89-94.

 

Comment: Figure 1 does not appear to be included for review.

Author comment: Apologies, this is now included.

 

Comment: any additional corrections when using unpaired t-test? For example, Welch's correction for unequal variances?

Author response: No we did not use additional corrections as we used means.

 

Comment: you discussed a limitation being the use of studies from the last 10 years and increasing the scope of review given timing of military conflicts. Why not do that for this study?

Author response: Although this is a limitation as discussed increasing the time and scope of the study would introduce more bias since the diagnosis of mTBI, which is the signature injury in the military has been difficult with improved methods being developed in the last 10 years. Hence, studies in the last 10 years should contain publications with better quality mTBI diagnosis and hence any insights would be more reliable.

 

Comment: good discussion on future directions and cautious in conclusions given number of papers and heterogeneity

Author response: Thank you.

Reviewer 3 Report

Thank you for all your efforts in responding to our comments ad suggestions. I believe the manuscript is now ready for publication. 

Author Response

Comment: Lines 20, 33: Change "compared to" to "compared with"

Author response: Amended.

 

Comment: Lines 37-40. Is this your definition for mTBI? or did you get this from another source? if so, a reference is needed.

Author response: Reference has been added in response to another reviewer comment also.

 

Comment: Line 87: Change ""...groups to..." to "...groups with..."

Author response: Amended, now line 99.

 

Comments: The introduction provides a comprehensive background supporting the aim of the review. The discussion section is also clearly written and very comprehensive. The authors conclusions are follow from the information presented in the discussion section.  

Author response: Thank you and thank you for taking the time to review our manuscript.

Reviewer 4 Report

Greatly improved manuscript - thank you. Please see edited file for additional comments.

Comments for author File: Comments.pdf

Author Response

Comment: As you will note for the comments I have made on your actual paper, one important figure and one table are apparently missing from your submission. I believe that these are crucial to the understanding of your paper.

Author response: Apologies for our oversight. Figure 1 and Table 3 are now included.

 

Comment: The methods and results sections are reasonably well explained, but your discussion requires extensive clarification as I have pointed out.

Author response: All of the changes suggested in the pdf version of our document from the reviewer has been addressed in the revised version (all tracked).

 

Comment: Since you have noted such extensive limitations I wonder if indeed you should repeat this study, applying some of the additional factors you outline.

Author response: The trouble with that is that we will have a new set of limitations since there is always some limitations in a systematic review. Hence, we feel that this would not be useful. We merely pointed these out in the review so that the reader is aware.