Review for 10.1186/s12876-021-01782-w (2021)

Reviewer’s report
Title: 
Prevalence of and risk factors for Metabolic associated fatty liver disease
in an urban population in China: a cross-sectional comparative study
Version: 
0 
Date: 
28 Feb 2021
Reviewer's report:
Dear authors,
The work you present brings a much-needed update in the epidemiological data
concerning the recently reconceptualized MALFD. However, I think the methods
and study design should be clarified. 
Please consider the following recommendations:
Tittle
Line 2: your study presents associations, thereby this study design fall under an
analytical, rather than descriptive, category of "cross-sectional comparative
study" - please correct it in the tittle.
Abstract
Line 15: methods should be more detailed.
Page 3
-Line 46: ". It is regarded…" instead of ", it is regarded";
-Line 51: "exclusion diagnosis" instead of "exclusive diagnosis".
Page 4
-Line 2: "exclusion" not "exclusive";
-Line 44: if most participants are urban residents, I would not use the term
"general Chinese population", since urban/rural life style strongly influences
MALFD associated risk factors
-Line 46: It should be clarified what was the setting of this health examination -
does this work as a screening program and everyone in the population is called?
If so, what is the rate of adherence? or are people recruited because of specific
reasons? This should be clarified because it may conceive selection bias
-Line 54: "September 2018. Most…" instead "September 2018, most..:"
-Line 56: "Our study involved 139170 participants which including 78176 males
(56.2%) and 60994 females (43.8%)." Confusing grammar. Please reformulate.
Page 5
Line 15: what was the reason to exclude "nephrectomy"?
Line 56: "Since the diagnosis of MAFLD does not involve the
assessment of alcohol consumption and hepatitis virus, here we didn't include the
two examinations in our study" but this is a limitation of your work because even
though it did not exclude the diagnosis, a subgroup analysis could be made and
would certainly be interesting. Would add this to the "limitations" in discussion.
PAGE 6
Line 15: "The diagnosis of MALFD is based on the ultrasonography" should be
change to "In our study, the diagnosis of MAFLD was based on the
ultrasonography", because other methods might be use to diagnose MALFD
beside US
PAGE 7
Line 32: Using age proxy instead patient reported menopausal history might
harbor information bias due to misclassification, should be specified in the
"limitations". Also, why do you use reference 11 and 12, since none of those
studies used age as a proxy for menopausal status?
PAGE 8
Line 42: "hematocrit" instead of "hematrokit";
Line 51: please be consistent and present significance value as in previous
sentence.
Line 25: "in the age range of 65-69" - according to your graphic it seems it
peaked at age of 69, while still rising at the range of 65-69;
Line 14: "To our knowledge, this is the first study focusing on the prevalence
and associated metabolic characteristics of MAFLD since the new definition of
MAFLD was set up" -This is contestable, please check: 
Prevalence of NAFLD,
MAFLD and associated advanced fibrosis in the contemporary United States
population, Feb 2021 DOI: 10.1111/liv.14828
PAGE 13
Line 12: "was an" - would change to "might be an" 
Line 15: 
"Besides, after stratification by menopausal status, the prevalence of
MAFLD in females rose steady from premenopausal period (6.1%) to
perimenopausal period (16.8%), then to postmenopausal period (30.2%) (Figure
2)." - I don't think it makes sense to present this again after saying in the
previous sentences that the increase of MAFLD with age and the possible
relation with menopausal status, since your definition of menopausal status was
solely based on age. So, you are just repeating the results in slightly different age
cut-offs. 
Line 22: "Is consistent" instead of "consists"
PAGE 17
Line 1: "cannot" instead of "can't" 
Line 59: "it is" instead of "it's"
Figure 1: why does the figure starts at age 24, and not 18, as it is reported in
text?
Publons Reviewer Recognition
. Springer Nature can send verification of this
review directly to Publons (a subsidiary of Clarivate Analytics). If you would
like to take advantage of this service, please click on the “Yes” option below.
Your name, email address, title of the reviewed manuscript, name of the journal,
and date of your review submission (the “Review Data”) will then be transmitted
to Publons after the final decision on the manuscript has been made. If you have
already registered at Publons, they will notify you of the receipt of this review
and update your profile 
as per your settings and their policy. If you are not
registered with Publons, you will receive an email from them asking you to
register in order for them to be able to recognize your review on your new
profile page. Publons may use the Review Data to generate derivative metadata
for the benefit of Publons and you as a reviewer, carefully considering the
sensitivity of such information. For example, Publons may verify your record as
a reviewer by updating your profile published on its webservice if you have
registered for such service or help editors to identify candidate reviewers. Please
find the details of processing in Publons’ privacy policy
https://publons.com/about/terms
No
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 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)
Is the study design appropriate to answer the research question (including the use
of appropriate controls), and are the conclusions supported by the evidence
presented?
Yes
Are the methods sufficiently described to allow the study to be repeated?
No
Is the use of statistics and treatment of uncertainties appropriate?
Yes
Is the presentation of the work clear?
No
Are the images in this manuscript (including electrophoretic gels and blots) free
from apparent manipulation?
Yes