Review for 10.1186/s12876-023-02899-w (2023)

Title: Prevalence of Gastro-oesophageal reflux disease, and its associated risk factors among
medical students: A nation-based cross-sectional study
Version: 2 Date: 03 Jul 2023
Reviewer's report:
The manuscript by Baklola et al provides an overview of the prevalence and risk factors
associated with gastroesophageal reflux disease (GERD) in a selected cohort of young age
patients. The effort of the authors is certainly remarkable considering that nearly 1000 patients
were included. Unfortunately, many issues are present and need major revisions before
evaluating the manuscript for a possible publication.
Major points:
1. In the introduction, the authors should provide a brief description not only of the
pathophysiology, but also of the diagnosis of GERD. Currently, it is well known how the modern
diagnosis of GERD is made according to the Lyon criteria.
2. In the study methods, the diagnosis of GERD is performed by a specific questionnaire (GerdQ)
which has previously been proposed in several studies. Despite this, the accuracy of this tool
is low (if 65% and sp 71%) and this is a limitation of the study that should be reported in a
dedicated section. Unfortunately, the lack of an objective evaluation of reflux disease (i.e., pH-
impedance monitoring) is an important limitation to point out.
3. A major issue concerns the authors' interpretation of the association between students
perceived stress level and increased prevalence of GERD. To date, it is known that
psychopathological distress is closely associated with functional disorders of the oesophagus,
namely hypersensitive oesophagus, and functional heartburn. Unfortunately, knowing the low
accuracy of the GerdQ, the above-mentioned association could be due to many undiagnosed
functional disorders. All of this should be addressed in the manuscript.
4. The statistical analysis has some significant shortcomings. The authors identify several factors
significantly associated with GERD in univariate analysis. The Bonferroni correction is missing,
but its application may be required. In multivariate logistic regression, the choice of variables
that entered the model is unclear. This whole methodology needs revision.
Minor points:
1. The first part of the results looks confusing. The sentence "The prevalence of gastroesophageal
reflux disease (GERD) was found to be 17.4% among study participants, with female
participants making up the majority (64%) of those who took part. The percentage of female
participants with GERD was 18.2%, which was a little higher than the male" should be rephrased
because it does not clarify different populations (i.e., male and female, male with GERD, female
with GERD).
2. In the discussion section, the authors state that there is an association between PPI use and
higher GERD prevalence. Unfortunately, no mention of such therapy is made in the study results
or tables.
3. In the second paragraph of the discussion, the authors compare the prevalence of GERD
observed in their study with the literature. It is useful to report how the diagnosis of GERD was
made in the studies cited by authors (i.e., objective or only symptomatic evaluations).
4. Obesity and overweight are known risk factors for GERD. Although, this association is
missing in the present study. The authors should provide a clearer discussion, and not just
comparing their results with the literature available. A possible cause could be the homogeneity
of the sample.
5. Tables seems not to be self-explained. A brief legends or footnote should be added.