Reviewer’s report
Title: 
The Level and Prevalence of Depression and Anxiety among Patients with
Different Subtypes of Irritable Bowel Syndrome: A Network Meta-analysis
Version: 
0 
Date: 
02 Jun 2020
Reviewer's report:
This is a meta-analysis of 11 studies with 4400 participants showing no
significant difference in the level of depression and anxiety among different
irritable bowel syndrome (IBS)-subtype patients.
Comments
There are serious limitations in this study such as: 1. difference in the definition
of IBS subtypes according to past Rome criteria (Rome III criteria were used in 4
studies, Rome II criteria in 6, one study just mentioned they used Rome criteria,
and no study has been published based on the current Rome IV criteria); 2.
depression and anxiety criteria were not uniform among the studies and different
measurement scales were used; 3. comorbidities and other factors that might
have contributed to depression and anxiety were not assessed (low quality
papers); and 4. matched healthy control groups were not employed by all studies.
The authors acknowledged that due to the high heterogeneity and small number
of studies, they did not conduct a meta-analysis. In a recent relative meta-
analysis published in 2019 (Zamani M, et al. Aliment Pharmacol Ther.
2019;50:132
‐
143), subgroup analyses from 5 studies showed that the pooled
prevalence rates of anxiety symptoms were 43.7% (95% CI: 33.2
‐
54.2), 35.5%
(95% CI: 26.9
‐
44.1) and 37% (95% CI: 26.9
‐
47) in patients with IBS
‐
C, IBS
‐
D
and IBS
‐
M respectively, i.e., quite similar in all subgroups, as in the present
study. However, Zamani et al. also reported a very high heterogeneity among the
studies (I2 = 93.6%). In view of the above-mentioned comments, I am afraid that
the present study is neither novel not reliable to draw definitive conclusions.
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.
No
Are the conclusions drawn adequately supported by the data shown?
If not, please explain in your comments to the authors.
No
Are you able to assess any statistics in the manuscript or would you
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 indicate the quality of language in the manuscript:
Acceptable
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 that 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, write '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
Reviewer Publication Consent.
 I agree for my report to be made available
under an Open Access Creative Commons CC-BY License (
http://creativecommons.org/licenses/by/4.0
) if this manuscript is accepted for
publication. Any comments that I do not wish to be included in the published
report have been included as confidential comments to the editor, which will not
be published.
If you are not happy for us to publish this report, please contact the editorial
office before completing the review.
If you wish, you can include your name in your published report. Please note
you must decide whether to include your name at the start of the process and
confirm this decision whenever prompted. If you change your decision later, we
will not be able to publish your name.
I agree to the terms of the CC-BY 4.0 license; please 
do not
 publish my name
with my report. (default)
Reviewer’s report
Title: 
The Level and Prevalence of Depression and Anxiety among Patients with
Different Subtypes of Irritable Bowel Syndrome: A Network Meta-analysis
Version: 
0 
Date: 
02 Jun 2020
Reviewer's report:
This is a meta-analysis of 11 studies with 4400 participants showing no
significant difference in the level of depression and anxiety among different
irritable bowel syndrome (IBS)-subtype patients.
Comments
There are serious limitations in this study such as: 1. difference in the definition
of IBS subtypes according to past Rome criteria (Rome III criteria were used in 4
studies, Rome II criteria in 6, one study just mentioned they used Rome criteria,
and no study has been published based on the current Rome IV criteria); 2.
depression and anxiety criteria were not uniform among the studies and different
measurement scales were used; 3. comorbidities and other factors that might
have contributed to depression and anxiety were not assessed (low quality
papers); and 4. matched healthy control groups were not employed by all studies.
The authors acknowledged that due to the high heterogeneity and small number
of studies, they did not conduct a meta-analysis. In a recent relative meta-
analysis published in 2019 (Zamani M, et al. Aliment Pharmacol Ther.
2019;50:132
‐
143), subgroup analyses from 5 studies showed that the pooled
prevalence rates of anxiety symptoms were 43.7% (95% CI: 33.2
‐
54.2), 35.5%
(95% CI: 26.9
‐
44.1) and 37% (95% CI: 26.9
‐
47) in patients with IBS
‐
C, IBS
‐
D
and IBS
‐
M respectively, i.e., quite similar in all subgroups, as in the present
study. However, Zamani et al. also reported a very high heterogeneity among the
studies (I2 = 93.6%). In view of the above-mentioned comments, I am afraid that
the present study is neither novel not reliable to draw definitive conclusions.
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.
No
Are the conclusions drawn adequately supported by the data shown?
If not, please explain in your comments to the authors.
No
Are you able to assess any statistics in the manuscript or would you
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 indicate the quality of language in the manuscript:
Acceptable
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 that 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, write '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
Reviewer Publication Consent.
 I agree for my report to be made available
under an Open Access Creative Commons CC-BY License (
http://creativecommons.org/licenses/by/4.0
) if this manuscript is accepted for
publication. Any comments that I do not wish to be included in the published
report have been included as confidential comments to the editor, which will not
be published.
If you are not happy for us to publish this report, please contact the editorial
office before completing the review.
If you wish, you can include your name in your published report. Please note
you must decide whether to include your name at the start of the process and
confirm this decision whenever prompted. If you change your decision later, we
will not be able to publish your name.
I agree to the terms of the CC-BY 4.0 license; please 
do not
 publish my name
with my report. (default)
Please review this paper.
user
Reviewer’s report
Title: 
The Level and Prevalence of Depression and Anxiety among Patients with
Different Subtypes of Irritable Bowel Syndrome: A Network Meta-analysis
Version: 
0 
Date: 
02 Jun 2020
Reviewer's report:
This is a meta-analysis of 11 studies with 4400 participants showing no
significant difference in the level of depression and anxiety among different
irritable bowel syndrome (IBS)-subtype patients.
Comments
There are serious limitations in this study such as: 1. difference in the definition
of IBS subtypes according to past Rome criteria (Rome III criteria were used in 4
studies, Rome II criteria in 6, one study just mentioned they used Rome criteria,
and no study has been published based on the current Rome IV criteria); 2.
depression and anxiety criteria were not uniform among the studies and different
measurement scales were used; 3. comorbidities and other factors that might
have contributed to depression and anxiety were not assessed (low quality
papers); and 4. matched healthy control groups were not employed by all studies.
The authors acknowledged that due to the high heterogeneity and small number
of studies, they did not conduct a meta-analysis. In a recent relative meta-
analysis published in 2019 (Zamani M, et al. Aliment Pharmacol Ther.
2019;50:132
‐
143), subgroup analyses from 5 studies showed that the pooled
prevalence rates of anxiety symptoms were 43.7% (95% CI: 33.2
‐
54.2), 35.5%
(95% CI: 26.9
‐
44.1) and 37% (95% CI: 26.9
‐
47) in patients with IBS
‐
C, IBS
‐
D
and IBS
‐
M respectively, i.e., quite similar in all subgroups, as in the present
study. However, Zamani et al. also reported a very high heterogeneity among the
studies (I2 = 93.6%). In view of the above-mentioned comments, I am afraid that
the present study is neither novel not reliable to draw definitive conclusions.
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.
No
Are the conclusions drawn adequately supported by the data shown?
If not, please explain in your comments to the authors.
No
Are you able to assess any statistics in the manuscript or would you
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 indicate the quality of language in the manuscript:
Acceptable
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 that 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, write '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
Reviewer Publication Consent.
 I agree for my report to be made available
under an Open Access Creative Commons CC-BY License (
http://creativecommons.org/licenses/by/4.0
) if this manuscript is accepted for
publication. Any comments that I do not wish to be included in the published
report have been included as confidential comments to the editor, which will not
be published.
If you are not happy for us to publish this report, please contact the editorial
office before completing the review.
If you wish, you can include your name in your published report. Please note
you must decide whether to include your name at the start of the process and
confirm this decision whenever prompted. If you change your decision later, we
will not be able to publish your name.
I agree to the terms of the CC-BY 4.0 license; please 
do not
 publish my name
with my report. (default)
assistant