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: 27 Sep 2015  
 
Reviewer: Ahmed  Messallam  
 
Reviewer's report:  
 
Study Population:  
The study population included patients with suspected cholangitis according to TG13, as 
opposed to definitive cholangitis which necessitates the presence of compatible imaging 
findings. Was there evidence of biliary dilat ion on ERCP/PTC? Or visualization of the cause of 
obstruction? Based on the date presented in table one the etiology of obstruction may be 
identified, and therefore these patients may meet TK13 criteria for definite cholangitis, and 
identifying them as suc h would be more appropriate  
 
Statistics:  
- All models were compared using pre -set 22 variables. The authors mention that variable 
selection models were inferior and therefore concluded that each predictor has a certain 
predictive value. Although this may b e true, including all variables, may not result in the 
optimal model using  
- Including the same variable as a continuous and dichotomous variable invalidates the 
assumption that all variables in the prediction model are independent (eg age continuous and 
dichotomized). This needs to be adjusted for. Was a test for non -correlation between the 
variables performed?  
 
Discussion  
The main advantage of this model as opposed to current guidelines (TG13) is that it‚ puts more 
wieght on the predictors that this data  show are associated with higher mortality. The 
management of the 3 groups as predicted by this model is the same as that of the TG13 which is 
based on similar variables without the need of a predictive model. It is unclear wether the 
utilization of the pr oposed model will results in a patient being classified in a different group 
(mild, moderate, severe) compared to the classification per current TG13, and therefore be 
managed differently. Did the authors compare the suggested recommendations of this model  to 
that of the TG13? Did the use of this model result in patients being classified differently?  
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
Yes 
 
Does the work include the necessary controls?  
If not , please specify which controls are required in your comments to the authors.  
 
No 
 
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:  
 
Needs some language corrections before being published  
 
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  
 
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