Review for 10.1186/s12876-021-01931-1 (2021)

Title: Helicobacter pylori infection in Iran: demographic, endoscopic and pathological factors
Version: 3 Date: 25 Mar 2021
Reviewer's report:
Introduction
1. Please add a brief description of Guilan province, Iran such as the population number or some
characteristics that appealing.
Material and Methods
The clearance of the method is important for the repeatability of the study and also the readiness
for the meta-analysis. Hopefully, these questions could help to improve the clearance. Please
add the answer and elaboration of each question below into the method section manuscripts
(start from page 3 line 108).
1. What is the time and duration of data collection.
2. What is the sampling methods, please elaborate.
3. Where are the biopsy location? For example, the biopsy was taken antrum and corpus.
4. How many biopsies were obtained in each location?
5. What kind of buffer were used after sample collection, is it formalin? Were all 5 biopsies
were used for histology evaluation?
6. Could you explain why did 5 biopsies were obtained, was it because you follow the biopsy
guideline from the Updated Sydney System?
7. What is the minimum age of the subjects included?
8. How did you examine the pathology? Please elaborate on the method from making the
paraffin block, what kind of staining did you use, what kind of antibody did you use (if using
histopathology).
9. How did you determine the H. pylori infection status? Is it by the visible bacteria from the
histology?  Because 5 biopsies is obtained, what is the minimum number of biopsies among
5 with a positive number to say Hp positive? How about determining Hp Negative? Please
elaborate more.
10. What is the criteria to evaluate the histology? Is there any reference that you can provide
in the manuscript? Currently, the widely used guideline is the OLGA score from the Updated
Sydney System. Many other studies many also have modification for these guidelines, but they
still follow the neutrophil, monocyte infiltration, atrophy and intestinal metaplasia.
11.  Please change “After obtaining moral consents..” to “informed consent”
12. It was mentioned in the discussion that you did multiple logistic regression, but I could not
find it in the method and results section.. if you performed it, please add in the method. It also
considered being a better statistical approach to analyze this data. It could give us Odd ratio that
is useful to measure the risk.
Results and Discussion
Please add the answer and elaboration of each question below into the method section
manuscripts (start from page 4).
1. What is written in paragraph 1 of the results section can be seen clearly in the table. I think it is
not necessary to repeat it again. The reader might expect some meaning of the content of table 1.
2. The table and figure order should be according to the order of writing in the results.
3. Please provide an interpretation of each table and figure.
4. Please add: figure legend, value number, x-axis and y-axis title.
5. From Table 4  please describe the criteria to determine each category incomplete and complete
metaplasia, normal and etc.
6. What is different between mucin decrease and atrophy? Can you provide literature that shows
the clinical significance of this difference?
7. Why in table 4 you found high-grade dysplasia in one patient but there is no gastric cancer
diagnosis in the endoscopy (Table 3) ? was it not visible?
8. In Table 3, What is different between Ulcers and Duodenal ulcer? Does “Ulcer” means
“Gastric Ulcer”?
9. In Table 3, there was a high proportion of ulcer and duodenal erosion, do you think it is
clinically significant? You can elaborate on this interesting fact and could be added in the
discussion why it happens.
10. You also found 40% atrophy in H. pylori-negative patients in Table 4. I think this is an
interesting finding that should be elaborate in the result, please also explain in the discussion.
11. You can also perform statistical analysis between the risk factors and gastric pathology only
in the H. pylori Negative, to understand what caused the atrophy in Hp negative.
12. In table 3 and 4, I think Gastrointestinal symptoms in the first column Is not a suitable title,
please change.
13.  We can see that Table 5 showed data about gastrointestinal symptoms please elaborate.
What is the meaning of this table? What does this table explain?
General
It is suggested for English proofreading.