Review for 10.1186/s12876-020-01200-7 (2020)

Reviewer’s report
Title: Infection Control in ERCP using a Duodenoscope with a Disposable Cap (ICECAP):
Rationale for and Design of a Randomized Controlled Trial
Version: 0 Date: 28 Dec 2019
Reviewer: Manabu Kawai
Reviewer's report:
This  study  protocol  was  written  about  infection  control  in  ERCP using  a  duodenoscope  with  a
disposable cap (ICECAP). This study will clarify some important issues to prevent persistent bacterial
contamination and infection transmission by ERCP. However further discussion would be required to
confirm this expected conclusion. Therefore, authors would clarify several matters that mentioned
below to confirm these expected conclusions.
1. Authors report that a parallel arm randomized controlled trial will be performed for which
520 patients will be recruited. ERCP using a duodenoscope with a disposable cap is expected as
a promising new modality that has the potential to drastically reduce or eliminate the rates of
duodenoscope-related infection. However, what is the expected rate of reduction of persistent
bacterial contamination rate by using a duodenoscope with a disposable cap? How was the
sample size (n=520) calculated for this primary endpoint? It is the most important to clarify the
presumption of sample size in carrying out a randomized controlled trial.
2. Bile infection due to pancreatic and biliary disease might adversely affect persistent bacterial
contamination in ERCP. In particular, Bile infection in biliary stone seems to be higher than that
in pancreatic disease such as chronic pancreatitis, pancreatic stones or pancreatic stricture. Any
indication to require ERCP will be eligible for this study. Therefore, this study might require
some  modulators  for  allocation  to  be  stratified  to  minimize  background  bias  due  to  the
difference of pancreatic and biliary disease between the two groups.
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.
Yes
Are the conclusions drawn adequately supported by the data shown?
If not, please explain in your comments to the authors.
Unable to assess
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 further
assessment in your comments to the editors.
I recommend additional statistical review
Quality of written English
Please indicate the quality of language in the manuscript:
Acceptable
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