Review for 10.1186/s12876-020-01439-0 (2020)

Reviewer’ s report
Title: An assessment of chromosomal alterations detected by fluorescence in situ hybridisation in
pancreatobiliary tract malignancy
Version: 1Date: 30 Apr 2019
Reviewer: Research Square Statistical Reviewer
Reviewer's report:
"STATISTICAL REVIEWER ASSESSMENT:Is the study design appropriate for the research question (considering whether the analyzed
population accurately reflects the design and whether you see any problems with control/comparison groups, e.g., likely confounders)?Yes - overall design, population, and control groups are appropriate
Are methodologies adequate and well implemented (considering whether assumptions are
addressed and whether analyses are robust)?No - there are minor issues
Are the analyses adequately communicated (considering whether reporting details are adequate
and whether figures and tables are well labeled and described)?No - there are minor issues
Does the interpretation accurately reflect the analyses without overstatement (considering whether
limitations/bias are acknowledged and whether accurate descriptors, e.g., 'significant', are used?
No - there are minor issues
Could an appropriately REVISED version of this work represent a statistically sound
contribution?Probably - with minor revisions
STATISTICAL REVIEWER COMMENTS:Overall the authors have performed an interesting study on the clinical utility of several diagnostic
methods for pancreatobiliary cancer. They have recruited a decent number of patients andemployed different diagnostic methods in order to compare their sensitivity, specificity, predictivevalues and accuracy for the disease. However, the authors have not given too many details aboutthe statistical tests employed for the analyses of each specific set of results, and therefore someminor corrections are needed before the manuscript could be of use of the general readership.
REQUESTED REVISIONS:
The authors have provided a broad description of the statistical methods (section ""Analysis"" on
page 8). It would be desirable to specify which methods have been used for each type of analysis.
For instance, the authors now write they have used ""standard parametric and nonparametric
methods, where appropriate"", but do not really describe for which comparison each type has beenused. Thus it is difficult to assess if the right test has been employed in every case.
I suggest to also write more in detail what is the aim of the study, and be consistent throughout the
manuscript. In some sections the authors write they aim to compare predictive values (e.g. firstline of the Methods), whereas in some other sections it seems they want to compare sensitivity andspecificity per se (e.g. last sentence in the Introduction). I suggest to explain all parameters arestudied (sensitivity, specificity, predictive values and accuracy) and define how they relate to each
other (considering some readers might not be familiar with the terminology).
In the Introduction and Discussion the authors mention a different range for the sensitivity of
brush cytology (6-64% vs 8-38%). I assume the first mention is global while the second mightrefer to their hospital or local area, but this should be clearly defined, or the ranges should bementioned as same.
When mentioning P values, the tables and other results should include by which test the
comparison was done.
Table 2 could include the results for the statistical comparison of the positive and negative results
(PPV and NPV , for instance?). The same applies to table 4.
The legend for figure 2 needs to specify what the colors represent.The Discussion should be more concise and focused around the diagnostic parameters by each
method, and therefore the clinical utility of the markers."
Are the methods appropriate and well described?
If not, please specify what is required in your comments to the authors.
NoDoes the work include the necessary controls?
If not, please specify which controls are required in your comments to the authors.
YesAre the conclusions drawn adequately supported by the data shown?
If not, please explain in your comments to the authors.
NoAre 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 further
assessment in your comments to the editors.
I am able to assess the statistics
Quality 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 thismanuscript, 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.
This reviewer has been recruited by a partner organization, Research Square. Reviewers with
declared or apparent competing interests are not utilized for these reviews. This reviewer hasagreed to publication of their comments online under a Creative Commons Attribution Licenseattributed to Research Square and was paid a small honorarium for completing the review within aspecified timeframe. Honoraria for reviews such as this are paid regardless of the reviewerrecommendation.
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