Review for 10.1186/s12876-020-01418-5 (2020)

Reviewer’ s report
Title: Relationship between time-varying status of reflux esophagitis and Helicobacter pylori and
progression to long-segment Barrett’ s esophagus: time-dependent Cox proportional-hazards
analysis
Version: 0Date: 23 May 2020
Reviewer's report:
The authors conducted a retrospective analysis comprising consecutive patients who underwent
medical check-up and tried to figure out the relationship between RE or H. pylori infection anderadication on the progression to LSBE. The study may bring important information for Japanesereaders. However, some concerns, especially regarding methodology, are found in this article asdescribed below.
1. As the authors mentioned in the limitation, the definition of LSBE and SSBE used in author's
article is a Japanese one and not the mostly used in the West, which were: "Any segment of BEmeasuring >3 cm has been classified as long-segment BE " or "SSBE is an abnormal appearingesophageal lining at endoscopy that is 3 cm".
2. The authors should demonstrate the detailed data of Prague criteria such as a median length of
BE (C&M) of the study population. The authors explained that the exact endoscopic assessment ofthe elongation of SSBE is difficult, however, that should be the most fundamental part of thisstudy. At least C&M length of BE should be demonstrated.
3. According to the authors' description, the diagnosis of BE was evaluated based on the
endoscopic images. If so, the authors should demonstrate how they decided endoscopically where
the EGJ was in more detail. Since there were many H.pylori positive patients who may haveatrophic gastritis, the decision of the site of EGJ should not have been easy. Was the finding ofdistal ends of palisade vessels used in this study to decide the site of EGJ?
4. In the hazard ratio for the progression to LSBE in the multivariable time-dependent Cox
models, smoking, hiatal hernia and PPI or H2RA seemed to be strongly associated with higherrates of progression to LSBE. Please discuss these results in the discussion, especially why takingPPI seemed to have higher risk of progression to LSBE should be discussed.
5. Were any patients having low-grade or high-grade dysplasia detected during the study period?
That should be mentioned in the result.
Are the methods appropriate and well described?
If not, please specify what is required in your comments to the authors.
No
Does the work include the necessary controls?
If not, please specify which controls are required in your comments to the authors.
Unable to assessAre the conclusions drawn adequately supported by the data shown?
If not, please explain in your comments to the authors.
No
Are you able to assess any statistics in the manuscript or would you recommend an
additional statistical review?If an additional statistical review is recommended, please specify what aspects require furtherassessment in your comments to the editors.
I am able to assess the statisticsQuality of written English
Please indicate the quality of language in the manuscript:
AcceptableDeclaration 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
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