Reviewer ’s report  
 
Title:  Is Discard Better than Return Gastric Residual Aspirates: A Systematic Review and M eta-
analysis  
 
Version: 0 Date: 25 Jan 2019 
 
Reviewer:  Thangaraj  Abiramalatha  
 
Reviewer’s report:  
 
I congratulate the authors for choosing a good topic and doing a reasonably good systematic 
review and meta -analysis. There is no recent systematic r eview on this topic (last review was in 
2014 and it included only 2 studies), and hence it would be worthwhile to publish the review. 
Though the available data is not conclusive and we cannot draw any conclusion from this review, 
the review summarizes the available evidence and points out the lack of adequate data and hence 
the need for adequately powered RCTs on this topic.  
 
 However, the article needs a lot of revision before it can be published:  
 
 
Major comments  
 
1. Was the protocol published in PROSPERO or any other registry? - Registration number 
to be stated  
 
 
Background  
 
2. Background reads vague. Could be written a little more elaborate. Preferably under the 
following headings 'Description of the condition', 'description of the intervention', 'how 
the intervention might work' and 'why this review is important'.  
 
 
Objectives  
 
3. Primary outcome and secondary outcomes should be mentioned. And each outcome 
needs to be defined.  
 
4. Specify the pre -planned 'subgroup analyses'  
 
 
Methods  
 
5. Eligibility criteria for inclusion in the review need to be clearly defined.  
 
a. Participants - age groups (since the neonatal study was not included),  
 
b. Definition of the intervention and comparison  
 
c. Timing of starting and ending of the intervention  
 
6. Search strategy - should be written in more detail. Because using the same 'search terms' 
as mentioned in the article, I could get 840 articles in PUBMED and 652 trials in 
CENTRAL. However, the authors have reported that only 91 articles were retrieved from 
all the databases.  
 
 
Results  
 
7. Table 1: Characteristics of included studies - can be presented better. It looks like the 
authors have just copy -pasted from the articles. Uniform language can be used for all the 
studies and telegraphic language can be used rather than sentences.  
 
8. Table on 'Excluded studies' - with reason for exclusion for each study (for the 8 full -text 
articles that were excluded) - can be made as 'online only' file  
 
9. Risk of bias assessment in individual studies (for included tr ials) - Table could be 
included. If there is space constraint, the table can be made as 'online only' file. The table 
has to have the following details:  
 
A. Random sequence generation (selection bias)  
 
B. Allocation concealment (selection bias)   
 
C. Blindi ng of participants and personnel (performance bias)  
 
D. Blinding of outcome assessors (detection bias)  
 
E. Attrition bias  
 
F. Reporting bias  
 
G. Other bias  
 
10. Information on allocation concealment could be obtained from the authors of the 3 trials - 
Behairy 2014, Booker 2000 and Wang 2017. Since lack of allocation concealment is a 
serious risk of bias.  
 
11. Behairy 2014 - method of randomization is not clear. The study is called as a 'quasi -
experimental study'. Booker 2000 - method of randomization is not cle ar. Again, these 
authors could be contacted to know the details on randomization.  
12. Gastric emptying delay: The numbers in the meta -analysis differ from those reported in 
the original studies. Are the authors looking at 'number of episodes of gastric em ptying 
delay' or 'number of patients with episodes of gastric emptying delay'? It is confusing. 
This is the reason why each outcome needs to be pre -defined  
 
13. Vomiting: The authors have included both nausea and vomiting in this outcome. Can the 
outcome b e renamed as 'nausea or vomiting'? Why Behairy 2014 study was not included 
in this particular outcome, when they had given the numbers?  
 
14. Diarrhea: Why Booker 2000 and Behairy AS 2014 studies were not included in this 
particular outcome, when they had g iven the numbers?  
 
15. Sensitivity analysis was done, but is not clearly reported - it was done for which 
outcome? and why was it done?  
 
16. GRADE SoF (Summary of Findings) table to be included. It will give the level of 
evidence for each outcome.  Conclusion has to be written based on the GRADE level of 
evidence for each outcome  
 
 
Minor comments  
 
1. The article needs a lot of language corr ections (syntax, punctuation etc), almost in every 
sentence.  
 
 
Title  
 
2. Primary outcome could be included in the title  
 
 
Abstract  
 
3. Objective to be stated separately. Including the primary and secondary outcomes  
 
4. Study eligibility criteria, participants a nd intervention and control groups need to be 
defined  
 
5. Data sources to be enlisted, rather than writing 'PUBMED et al'  
 
6. p value need not be included in the results from a meta -analysis  
 
7. Systematic review registration number in PROSPERO or any other r egistry to be stated at 
the end of the abstract  
 
 
Methods  
 
8. ln 78: 'collaboration' spelling needs to be corrected  
 
9. Data synthesis and analysis: Could be written as 'we intended to do subgroup analysis if.. 
and analyze Publication bias if…' - since these t wo were not actually done.  
 
 
Results  
 
10. No need to mention the p value for the estimates in a meta -analysis. p should not be 
written in capital letter  
 
 
Discussion  
 
11. line 248: double negative 'no funnel plots' and weren't. The sentence needs to be revise d. 
 
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
No 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Yes 
 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
Are you able to assess any statistics in the manuscript or would yo u recommend an 
additional statistical review?  
If an additional statistical review is recommended, please specify what aspects require further 
assessment in your comments to the editors.  
 
I am able to assess the statistics  
 
Quality of written English  
Please in dicate the quality of language in the manuscript:  
 
Needs some language corrections before being published  
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following questions:  
 
1. Have you in the past five years received reimbursements, fees, funding, or salary from an 
organisation that may in any way gain or lose financially from the publication of this 
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation that may in any way gain or lose 
financially from the publication of this manuscript, either now or in the future?  
 
3. Do you hold or are you currently applying for any patents relating to the content of the 
manuscript?  
 
4. Have you received reimbursements, fees, funding, or salary from an organization tha t 
holds or has applied for patents relating to the content of the manuscript?  
 
5. Do you have any other financial competing interests?  
 
6. Do you have any non -financial competing interests in relation to this paper?  
 
If you can answer no to all of the above, wri te 'I declare that I have no competing interests' 
below. If your reply is yes to any, please give details below.  
 
I declare that I have no competing interests  
 
I agree to the open peer review policy of the journal. I understand that my name will be include d 
on my report to the authors and, if the manuscript is accepted for publication, my named report 
including any attachments I upload will be posted on the website along with the authors' 
responses. I agree for my report to be made available under an Open A ccess Creative Commons 
CC-BY license ( http://creativecommons.org/licenses/by/4.0/ ). I understand that any comments 
which I do not wish to be included in my named report can be included as confidential comments 
to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal  
Reviewer ’s report  
 
Title:  Is Discard Better than Return Gastric Residual Aspirates: A Systematic Review and M eta-
analysis  
 
Version: 0 Date: 25 Jan 2019 
 
Reviewer:  Thangaraj  Abiramalatha  
 
Reviewer’s report:  
 
I congratulate the authors for choosing a good topic and doing a reasonably good systematic 
review and meta -analysis. There is no recent systematic r eview on this topic (last review was in 
2014 and it included only 2 studies), and hence it would be worthwhile to publish the review. 
Though the available data is not conclusive and we cannot draw any conclusion from this review, 
the review summarizes the available evidence and points out the lack of adequate data and hence 
the need for adequately powered RCTs on this topic.  
 
 However, the article needs a lot of revision before it can be published:  
 
 
Major comments  
 
1. Was the protocol published in PROSPERO or any other registry? - Registration number 
to be stated  
 
 
Background  
 
2. Background reads vague. Could be written a little more elaborate. Preferably under the 
following headings 'Description of the condition', 'description of the intervention', 'how 
the intervention might work' and 'why this review is important'.  
 
 
Objectives  
 
3. Primary outcome and secondary outcomes should be mentioned. And each outcome 
needs to be defined.  
 
4. Specify the pre -planned 'subgroup analyses'  
 
 
Methods  
 
5. Eligibility criteria for inclusion in the review need to be clearly defined.  
 
a. Participants - age groups (since the neonatal study was not included),  
 
b. Definition of the intervention and comparison  
 
c. Timing of starting and ending of the intervention  
 
6. Search strategy - should be written in more detail. Because using the same 'search terms' 
as mentioned in the article, I could get 840 articles in PUBMED and 652 trials in 
CENTRAL. However, the authors have reported that only 91 articles were retrieved from 
all the databases.  
 
 
Results  
 
7. Table 1: Characteristics of included studies - can be presented better. It looks like the 
authors have just copy -pasted from the articles. Uniform language can be used for all the 
studies and telegraphic language can be used rather than sentences.  
 
8. Table on 'Excluded studies' - with reason for exclusion for each study (for the 8 full -text 
articles that were excluded) - can be made as 'online only' file  
 
9. Risk of bias assessment in individual studies (for included tr ials) - Table could be 
included. If there is space constraint, the table can be made as 'online only' file. The table 
has to have the following details:  
 
A. Random sequence generation (selection bias)  
 
B. Allocation concealment (selection bias)   
 
C. Blindi ng of participants and personnel (performance bias)  
 
D. Blinding of outcome assessors (detection bias)  
 
E. Attrition bias  
 
F. Reporting bias  
 
G. Other bias  
 
10. Information on allocation concealment could be obtained from the authors of the 3 trials - 
Behairy 2014, Booker 2000 and Wang 2017. Since lack of allocation concealment is a 
serious risk of bias.  
 
11. Behairy 2014 - method of randomization is not clear. The study is called as a 'quasi -
experimental study'. Booker 2000 - method of randomization is not cle ar. Again, these 
authors could be contacted to know the details on randomization.  
12. Gastric emptying delay: The numbers in the meta -analysis differ from those reported in 
the original studies. Are the authors looking at 'number of episodes of gastric em ptying 
delay' or 'number of patients with episodes of gastric emptying delay'? It is confusing. 
This is the reason why each outcome needs to be pre -defined  
 
13. Vomiting: The authors have included both nausea and vomiting in this outcome. Can the 
outcome b e renamed as 'nausea or vomiting'? Why Behairy 2014 study was not included 
in this particular outcome, when they had given the numbers?  
 
14. Diarrhea: Why Booker 2000 and Behairy AS 2014 studies were not included in this 
particular outcome, when they had g iven the numbers?  
 
15. Sensitivity analysis was done, but is not clearly reported - it was done for which 
outcome? and why was it done?  
 
16. GRADE SoF (Summary of Findings) table to be included. It will give the level of 
evidence for each outcome.  Conclusion has to be written based on the GRADE level of 
evidence for each outcome  
 
 
Minor comments  
 
1. The article needs a lot of language corr ections (syntax, punctuation etc), almost in every 
sentence.  
 
 
Title  
 
2. Primary outcome could be included in the title  
 
 
Abstract  
 
3. Objective to be stated separately. Including the primary and secondary outcomes  
 
4. Study eligibility criteria, participants a nd intervention and control groups need to be 
defined  
 
5. Data sources to be enlisted, rather than writing 'PUBMED et al'  
 
6. p value need not be included in the results from a meta -analysis  
 
7. Systematic review registration number in PROSPERO or any other r egistry to be stated at 
the end of the abstract  
 
 
Methods  
 
8. ln 78: 'collaboration' spelling needs to be corrected  
 
9. Data synthesis and analysis: Could be written as 'we intended to do subgroup analysis if.. 
and analyze Publication bias if…' - since these t wo were not actually done.  
 
 
Results  
 
10. No need to mention the p value for the estimates in a meta -analysis. p should not be 
written in capital letter  
 
 
Discussion  
 
11. line 248: double negative 'no funnel plots' and weren't. The sentence needs to be revise d. 
 
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
No 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Yes 
 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
Are you able to assess any statistics in the manuscript or would yo u recommend an 
additional statistical review?  
If an additional statistical review is recommended, please specify what aspects require further 
assessment in your comments to the editors.  
 
I am able to assess the statistics  
 
Quality of written English  
Please in dicate the quality of language in the manuscript:  
 
Needs some language corrections before being published  
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following questions:  
 
1. Have you in the past five years received reimbursements, fees, funding, or salary from an 
organisation that may in any way gain or lose financially from the publication of this 
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation that may in any way gain or lose 
financially from the publication of this manuscript, either now or in the future?  
 
3. Do you hold or are you currently applying for any patents relating to the content of the 
manuscript?  
 
4. Have you received reimbursements, fees, funding, or salary from an organization tha t 
holds or has applied for patents relating to the content of the manuscript?  
 
5. Do you have any other financial competing interests?  
 
6. Do you have any non -financial competing interests in relation to this paper?  
 
If you can answer no to all of the above, wri te 'I declare that I have no competing interests' 
below. If your reply is yes to any, please give details below.  
 
I declare that I have no competing interests  
 
I agree to the open peer review policy of the journal. I understand that my name will be include d 
on my report to the authors and, if the manuscript is accepted for publication, my named report 
including any attachments I upload will be posted on the website along with the authors' 
responses. I agree for my report to be made available under an Open A ccess Creative Commons 
CC-BY license ( http://creativecommons.org/licenses/by/4.0/ ). I understand that any comments 
which I do not wish to be included in my named report can be included as confidential comments 
to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal  
Please review this paper.
user
Reviewer ’s report  
 
Title:  Is Discard Better than Return Gastric Residual Aspirates: A Systematic Review and M eta-
analysis  
 
Version: 0 Date: 25 Jan 2019 
 
Reviewer:  Thangaraj  Abiramalatha  
 
Reviewer’s report:  
 
I congratulate the authors for choosing a good topic and doing a reasonably good systematic 
review and meta -analysis. There is no recent systematic r eview on this topic (last review was in 
2014 and it included only 2 studies), and hence it would be worthwhile to publish the review. 
Though the available data is not conclusive and we cannot draw any conclusion from this review, 
the review summarizes the available evidence and points out the lack of adequate data and hence 
the need for adequately powered RCTs on this topic.  
 
 However, the article needs a lot of revision before it can be published:  
 
 
Major comments  
 
1. Was the protocol published in PROSPERO or any other registry? - Registration number 
to be stated  
 
 
Background  
 
2. Background reads vague. Could be written a little more elaborate. Preferably under the 
following headings 'Description of the condition', 'description of the intervention', 'how 
the intervention might work' and 'why this review is important'.  
 
 
Objectives  
 
3. Primary outcome and secondary outcomes should be mentioned. And each outcome 
needs to be defined.  
 
4. Specify the pre -planned 'subgroup analyses'  
 
 
Methods  
 
5. Eligibility criteria for inclusion in the review need to be clearly defined.  
 
a. Participants - age groups (since the neonatal study was not included),  
 
b. Definition of the intervention and comparison  
 
c. Timing of starting and ending of the intervention  
 
6. Search strategy - should be written in more detail. Because using the same 'search terms' 
as mentioned in the article, I could get 840 articles in PUBMED and 652 trials in 
CENTRAL. However, the authors have reported that only 91 articles were retrieved from 
all the databases.  
 
 
Results  
 
7. Table 1: Characteristics of included studies - can be presented better. It looks like the 
authors have just copy -pasted from the articles. Uniform language can be used for all the 
studies and telegraphic language can be used rather than sentences.  
 
8. Table on 'Excluded studies' - with reason for exclusion for each study (for the 8 full -text 
articles that were excluded) - can be made as 'online only' file  
 
9. Risk of bias assessment in individual studies (for included tr ials) - Table could be 
included. If there is space constraint, the table can be made as 'online only' file. The table 
has to have the following details:  
 
A. Random sequence generation (selection bias)  
 
B. Allocation concealment (selection bias)   
 
C. Blindi ng of participants and personnel (performance bias)  
 
D. Blinding of outcome assessors (detection bias)  
 
E. Attrition bias  
 
F. Reporting bias  
 
G. Other bias  
 
10. Information on allocation concealment could be obtained from the authors of the 3 trials - 
Behairy 2014, Booker 2000 and Wang 2017. Since lack of allocation concealment is a 
serious risk of bias.  
 
11. Behairy 2014 - method of randomization is not clear. The study is called as a 'quasi -
experimental study'. Booker 2000 - method of randomization is not cle ar. Again, these 
authors could be contacted to know the details on randomization.  
12. Gastric emptying delay: The numbers in the meta -analysis differ from those reported in 
the original studies. Are the authors looking at 'number of episodes of gastric em ptying 
delay' or 'number of patients with episodes of gastric emptying delay'? It is confusing. 
This is the reason why each outcome needs to be pre -defined  
 
13. Vomiting: The authors have included both nausea and vomiting in this outcome. Can the 
outcome b e renamed as 'nausea or vomiting'? Why Behairy 2014 study was not included 
in this particular outcome, when they had given the numbers?  
 
14. Diarrhea: Why Booker 2000 and Behairy AS 2014 studies were not included in this 
particular outcome, when they had g iven the numbers?  
 
15. Sensitivity analysis was done, but is not clearly reported - it was done for which 
outcome? and why was it done?  
 
16. GRADE SoF (Summary of Findings) table to be included. It will give the level of 
evidence for each outcome.  Conclusion has to be written based on the GRADE level of 
evidence for each outcome  
 
 
Minor comments  
 
1. The article needs a lot of language corr ections (syntax, punctuation etc), almost in every 
sentence.  
 
 
Title  
 
2. Primary outcome could be included in the title  
 
 
Abstract  
 
3. Objective to be stated separately. Including the primary and secondary outcomes  
 
4. Study eligibility criteria, participants a nd intervention and control groups need to be 
defined  
 
5. Data sources to be enlisted, rather than writing 'PUBMED et al'  
 
6. p value need not be included in the results from a meta -analysis  
 
7. Systematic review registration number in PROSPERO or any other r egistry to be stated at 
the end of the abstract  
 
 
Methods  
 
8. ln 78: 'collaboration' spelling needs to be corrected  
 
9. Data synthesis and analysis: Could be written as 'we intended to do subgroup analysis if.. 
and analyze Publication bias if…' - since these t wo were not actually done.  
 
 
Results  
 
10. No need to mention the p value for the estimates in a meta -analysis. p should not be 
written in capital letter  
 
 
Discussion  
 
11. line 248: double negative 'no funnel plots' and weren't. The sentence needs to be revise d. 
 
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
No 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Yes 
 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
Are you able to assess any statistics in the manuscript or would yo u recommend an 
additional statistical review?  
If an additional statistical review is recommended, please specify what aspects require further 
assessment in your comments to the editors.  
 
I am able to assess the statistics  
 
Quality of written English  
Please in dicate the quality of language in the manuscript:  
 
Needs some language corrections before being published  
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following questions:  
 
1. Have you in the past five years received reimbursements, fees, funding, or salary from an 
organisation that may in any way gain or lose financially from the publication of this 
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation that may in any way gain or lose 
financially from the publication of this manuscript, either now or in the future?  
 
3. Do you hold or are you currently applying for any patents relating to the content of the 
manuscript?  
 
4. Have you received reimbursements, fees, funding, or salary from an organization tha t 
holds or has applied for patents relating to the content of the manuscript?  
 
5. Do you have any other financial competing interests?  
 
6. Do you have any non -financial competing interests in relation to this paper?  
 
If you can answer no to all of the above, wri te 'I declare that I have no competing interests' 
below. If your reply is yes to any, please give details below.  
 
I declare that I have no competing interests  
 
I agree to the open peer review policy of the journal. I understand that my name will be include d 
on my report to the authors and, if the manuscript is accepted for publication, my named report 
including any attachments I upload will be posted on the website along with the authors' 
responses. I agree for my report to be made available under an Open A ccess Creative Commons 
CC-BY license ( http://creativecommons.org/licenses/by/4.0/ ). I understand that any comments 
which I do not wish to be included in my named report can be included as confidential comments 
to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal  
assistant