Review for 10.1186/s12876-022-02096-1 (2022)

Title: The effect of group-based education on gastrointestinal symptoms and quality of life in
patients with celiac disease: Randomized controlled clinical trial
Version: 6 Date: 14 Oct 2021
Reviewer:  Pilvi Laurikka
Reviewer's report:
The study design of the present study is clear and clinically relevant. The main result is that celiac
disease patients benefit from group education considering the management of their disease. The
results are interesting and I see no ethical problems. However, I have couple of suggestions to
further clarify the results and make their interpretation easier for the reader.
Abstract:
- It is not evident what kind of celiac disease patients the study population consists of; whether
they are newly diagnosed patients receiving their first education about the diet or patients having
followed gluten-free diet for a longer time. This is clarified later in the methods section, but I
think it’d be good to clarify it already in the abstract. Based on abstract alone, I’d have presumed
the patients to be newly diagnosed.
Background:
- References #13 and 14 have been published several years ago. Is there some newer reference
available? I´d also be interested if adherence to GFD has been studied in Iran? If yes, I’d add the
citation here. Also, I’d not say that adherence is bad everywhere, but it varies a lot. In Finland/
Northern Europe for example, the adherence to GFD is generally good. There are probably
multiple cultural and practical reasons why the adherence varies so much between countries.
Methods and material:
Patiens selection paragraph:
-  You refer to citation #24. I agree that it makes the manuscript more readable not to repeat
all the details, if they are explained elsewhere. However, as majority of the readers probably
won´t check the citation for further information, I’d consider to briefly describe the main details
also here.
Intervention paragraph:
- It is a bit unclear if the intervention sessions lasted 3 hours each (= altogether 9 hours) or one
hour each (=altogether three hours).
- “An expert dietitian conducted all educational sessions in the intervention and the control
group with the same educational content.“ I would move this sentence earlier. When reading
the description about intervention sessions I was already wondering who gave the education, so
maybe at the beginning of that paragraph?
Statistical analyses paragraph:
- Were all the variables truly normally distributed? My own experience on using GSRS
questionnaire is that variables are often skewed, and non-parametric tests have to be used. Of
course, this may depend on the study population.
Results
- Second paragraph: I think age can also be reported with fewer decimals. I also think that there’s
no need to repeat the numeric values of the baseline characteristics both in the text and in the
table, the text becomes more concise if you just say that there were no differences and refer
to table 1.
- Throughout the results I’d rather say “GSRS total score” than “GSRS score” to better
differentiate total score from sub-dimension scores.
Discussion:
- In second paragraph you say: “Clinical improvement in some psychiatric symptoms such as
depression, anxiety, and irritability was observed after administration of a GFD in CD (28). It
seems that the gut can influence the blood-brain barrier through secretion of gastro-intestinal-
derived hormones, small molecule, and production of metabolic cofactors (29)” I think this is
an interesting theory, but the discussion remains a bit narrow here. Maybe the patient was just
worried about his/her symptoms and after having a diagnosis and resolution of symptoms, also
depression and anxiety alleviate? Moreover, there are also many contradictory results, where
these symptoms have even increased after beginning of GFD (see e.g. Wolf et al Dig Dis Sci
2018 Jun;63(6):1438-1448). I mean that psychiatric symptoms and quality of life are compelx
issues and as it is your main result that symptoms and QoL improved with group-education, I’d
take a little bit broader perspective.
Conclusions:
- “The results of the present study showed that group-based education had statistically significant
effects on improving GI symptoms as well as QOL.” I’d add “compared with…”
Table 2
- The table is somewhat difficult to interpret for me. The headline tells that it is comparison of
mean scores, but when looking the numeric values in the table it seems to me that they are sums
of the questions considering each sub-dimension/ total score, as the range is larger than 1-7.
Please clarify this issue. Also, I’m used to interpreting GSRS scores as calculated mean values
instead of the sum, since that way the scores are presented on a same Likert-scale than patients
use when filling the questionnaire. Of course, reporting sum is not wrong, but I’d consider to
report also mean values to make interpretation easier.
- Secondly, the table heading says that you compare intervention group and control group, but
there are both paired comparison between pre- and post-intervention AND comparison between
intervention group and control group. Basically one has to remember how the statistical analyses
mentioned in the footnote are used to figure this out. I think it’s not necessary to mention the
specific statistical analysis in the table if they are listed in the Statisctics section, but instead the
table should be readable without going back to check anything from the main text.
- Have you considered presenting some of the information as a figure? I think that e.g. your
main result that intervention group had fewer symptoms and better quality of life than control
group would look great and clearer as a figure.