Review for 10.1186/s12876-016-0428-1 (2016)

Revie wer’s report  
 
Title: Mortality Risk for Acute Cholangitis (MAC): A risk prediction m odel for in -hospital 
mortality in patients with acute cholangitis  
 
Version: 0 Date: 07 Oct 2015  
 
Reviewer: Askin  Erdogan  
 
Reviewer's report:  
 
Dear Editor,  
 
I have revised the paper "Mortality Risk for Acute Cholangitis (MAC): A risk  prediction model 
for in -hospital mortality in patients with acute cholangitis". The study  aims to create a feasible 
risk model for predicting mortality in patients with acute cholangitis. Approximately 70 -80% 
patients with acute cholangitis can be treated with conservative management with antiobotics 
therapy and patient with low risk mortality  can be waited 24 -48 hours for suitable condition such 
as expreinced staff.   Therefore initial risk evaluation is important. However I have some 
concerns regarding the paper as listed below.  
 
Background:  
1. Although the authors state that the study aims w ere to create a feasible risk model for 
predicting mortality in patients with acute cholangitis and also provide an orientation how 
fast a biliary drainage should be performed and how potent antibiotic therapy should be, 
they need to explain pros and cones  of Japan guidelines and why they needed a new model.  
 
Methods:  
1. The authors give the patient characteristics for study inclusion. Having fever >38°C and/or 
elevated infectious parameters as well as elevated cholestasis parameters  were given as the  
inclusion criteria. According to this patients with low risk according to Tokyo criteria were 
probably excluded. May be recruiting patients not fitting moderate/high risk according to 
Tokyo criteria might be more covering.  
2. The authors state that organ fai lure was mainly based on Tokyo guidelines, so they 
incorporate mainly Tokyo guideline into their model.  
3. The authors state that the sensitivity, specificity, positive and negative predictive value of 
the corresponding optimal cut -point were 82.9%, 85.1%,  19.0% and 99.3%, respectively. 
What was the gold standard and it is interesting to have a very low positive predictive value. 
I would suggest checking for this.  
4. How many patients were not enrolled in this study due to incomplete data records (missing 
laboratory values or medical examination), end stage liver cirrhosis as well as other focus of 
infection???  
5. The authors give the data as follows: leucocytes > 15 G/l, platelet count< 100 G/L, (Is G 
equal to x109/L?)  
 
Results:  
1. Univariate analysis of p redictors for mortality: Biliary drainage and appropriate antibiotics 
are essential to prevent mortality for acute cholangitis. Were all patients given same 
antibiotics during study period? Please give more information.  
 
Discussion  
1. "….other si gnificant risk predictors like respiratory rate > 120/min,…" is the respiratory rate 
correct?  
2. If positive predictive value is really that low then as authors state that very small number of 
patients assigned a high mortality risk will actually die. So t hey will actually will not need to 
go urgent drainage although not needed to be urgent.  
3. Please state the advantage of this model over Tokyo guideline and what adds up to the 
literature.  
 
Yours sincerely,  
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 assess  
 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
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  
 
Declaration of competing interests  
Please complete a declaration of competing interest s, 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 ho ld 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 tha t I have no competing interests  
 
I agree to the open peer review policy of the journal. I understand that my name will be included 
on my report to the authors and, if the manuscript is accepted for publication, my named report 
including any attachments I upl oad will be posted on the website along with the authors' 
responses. I agree for my report to be made available under an  Open Access Creative Commons 
CC-BY license ( http://creativecommons.org/licenses/by/4.0/).  I understand that any comments 
which I do not  wish to be included in my named report can be included as confidential comments 
to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal