Review for 10.1186/s12876-020-01296-x (2020)

Reviewer’ s report
Title: Elderly-onset vs adult-onset Ulcerative Colitis: a different natural history?
Version: 1Date: 20 Feb 2020
Reviewer: Piotr Eder
Reviewer's report:
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 textformat.Please overwrite this text when adding your comments to the authors.This is a well writtenpaper related to a very important topic. In my opinion, the paper deserves publication in BMCGastroenterology. My only comment is on the mortality rates in the study groups. Could theauthors present what were the causes of patients' deaths in both groups. Were they related in anycase to IBD itseld or its treatment - this would be especially interesting among the elderly patients?Another issue - what was the most frequent type of surgery among elderly patients and was itdifferent when compared with younger ones ?
Are the methods appropriate and well described?
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YesDoes the work include the necessary controls?
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YesAre the conclusions drawn adequately supported by the data shown?
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YesAre 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
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Acceptable
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