Review for 10.1186/s12876-021-01673-0 (2021)

Reviewer’s report
Title: 
The impact of symptoms on quality of life before and after diagnosis of
coeliac disease: the results from a Polish population survey and comparison with
the results from the United Kingdom
Version: 
1 
Date: 
02 Sep 2020
Reviewer's report:
The Authors prompted by the suspicion that in Poland the mean time between
the onset of coeliac symptoms and CD diagnosis can be even longer than that
reported in a study published 10 years before in the UK, conducted a similar
study using comparable instruments and methods among Polish CD patients.
This study aimed at analysing the diagnostic process of CD in Poland and
evaluating the quality of life of patients before and after CD diagnosis. In
addition, results were compared to the results of the original study conducted in
the UK. 
The survey included 2,500 members of the Polish Coeliac Society.
Questionnaires received from 796 respondents were included in the final
analysis. 
The conclusions were: 
Duration of symptoms prior to the diagnosis of
CD in Poland, although shorter than in the UK, was long with an average of 7.3
years from first CD symptoms. Faster CD diagnosis after the onset of symptoms
in Polish respondents may be related to a higher percentage of children in the
Polish sample. Introduction of a gluten-free diet improves coeliac patients'
quality of life.
With respect to the first objective, that is delay in diagnosis and related costs,
this issue is relevant because knowing these data can suggest health policies that
could bridge the diagnostic gap for celiac disease thus lowering costs, not only
economic ones.
Regarding the objective to assess the quality of life (QoL) before and after
diagnosis of CD, this issues has already been addressed in many studies and a
recent systematic review (Clin Nutr. 2017;36:399-406), not cited by Majsiak et
al, 
showed that a GFD significantly improved QOL in patients with CD.
Morever another study, not cited by Majsiak et al, differentiated QoL 
between
patients with nonclassical and classical presentation of CD (Choung RS et al. J
Clin Gastroenterol 2020;54:620-625).
The retrospective design of the studies performed in UK and Poland and the
patients considered in both the studies who are members of the UK and Polish
Coeliac Society, respectively, should make the Authors to consider and discuss
some responder bias and differences in methods with previous studies already
published, and some not cited by Majsiak et al.
It is possible that the responders were more motivated to do it because they had a
longer delay of diagnosis and more severe disease. This is unavoidable in a
questionnaire asked to Celiac Society Members as done in UK and Poland
studies without a control cohort collected in a tertiary or Celiac Centre. 
This
cohort should be included collecting the CD cases diagnosed and in follow up at
the Centres to which the Authors of the study belong. In the UK study a total
membership of 70,000 or 56% of the estimated 125,000 people with a clinical
diagnosis of coeliac disease in the UK as of October 2007 are reported. What is
the estimated celiac population in Poland? Does a CD registry exist in Poland? 
The difference in time between diagnosis and and questionnaire compilation is
about 5 five years in Poland and more than 10 years in UK. Even in the above
cited study by Choung et al. 
among a total of 1930 subjects diagnosed at their
tertiary center only 335 were included in the study that are those who had a
baseline questionnaire completed within 30 days of their diagnosis. Otherwise, it
is difficult to compare the present symptoms with those presented at diagnosis.
Due to the design and setting of the Majsiak et al. study, it is impossible to
recover these informations but at least a comparison of QoL before and after
diagnosis in a cohort of CD patients diagnosed and in follow up in the Authors'
centres should be tried.
A difference between patients with classical and nonclassical presentation should
be made.
Morever the Authors report that there is a difference in the number of children
and
adults who took part in the studis in UK and in Poland that may have influenced
the results regarding the delay of diagnosis. They are right and the results should
be reported and discussed separately for adults and children also looking for the
delay of diagnosis according to patients' age.
One limitation of the questionnaire is that it is utilized for adults and children.
Looking at the questionnaire, the questions regarding symptoms asked to adults
cannot fit in children in whom symptoms defined by the ESPGHAN should be
looked for. 
Majsiak et al replicated the study performed 10 years before in UK in which the
Authors stated that the EQ- 5D is the only quality of life instrument specifically
recommended for calculating quality adjusted life years by the National Institute
of Health and Clinical Excellence in its recommended methods for technology
appraisal. This issue should 
be addressed in the Discussion comparing this
methods with others widely utilized in gastronterology such as that suggested by
Talley et al (Annals of Internal Medicine. 1989;111:671-674) and the 
36-Item
Short Form Survey Instrument (SF-36)
(https://form.jotform.com/71537611884159) 
The references do not follow the editorial policies for author guidance on good
citation practice of the Journal and the Vancouver reference style. 
Example: 
Reference 1 Clin Gastroenterol Hepatol 2018;16:823-836 NOT Clinical
gastroenterology and hepatology : the official clinical practice journal of the
American Gastroenterological Association.
2018;16(6):823-36 e2.
Reference 2 J Clin Gastroenterol 2013;47:121-6 NOT Journal of clinical
gastroenterology. 2013;47(2):121-6
Reference N. 7: J Pediatr Gastroenterol Nutr 
2017;64(1):e1-e6 
NOT 
Journal of
pediatric gastroenterology and nutrition. 2017;64(1):e1-e6.
Reference N. 17: Arch Med Sci. 2017;13:191-200 
NOT Archives of medical
science : AMS. 2017;13(1):191-200.
Please include all comments for the authors in this box rather than uploading
your report as an attachment. Please only upload as attachments annotated
versions of manuscripts, graphs, supporting materials or other aspects of your
report which cannot be included in a text format.
Please overwrite this text when adding your comments to the authors.
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 upon publication of the manuscript. 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
Yes
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 publish my name with my
report.
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?
No
Are the methods sufficiently described to allow the study to be repeated?
Yes
Is the use of statistics and treatment of uncertainties appropriate?
Yes
Is the presentation of the work clear?
Yes
Are the images in this manuscript (including electrophoretic gels and blots) free
from apparent manipulation?
Yes