Review for 10.1186/s12876-016-0551-z (2016)

Reviewer ’s report  
 
Title: Long -Term Outcomes of Liver Transplantation in Patients with Hepatitis C Infection are  
Not Affected by HCV Positivity of a Donor  
 
Version: 0 Date: 03 Aug 2016  
 
Reviewer: Alessandro Vitale  
 
Reviewer's report:  
 
This is a potential very interesting study evaluating the impact of HCV positive donors on post 
LT outcome of HCV recipients.  
The authors used the UNOS database, the largest database on LT available worldwide.  
However, I have a  major perplexity about methods and results of this paper.  
The authors showed that the two populations receiving HCV+ and - donors had several 
significant differences both in terms of recipients and donors characteristics. Thus, the main 
result of this stu dy (similar post LT results between the two cohorts) could be biased by other 
confounding covariates (i.e. the lower MELD of patients receiving HCV+ donors).  
The ideal methodology to compare the two cohort should correct for these potential confounders 
by using a propensity score analysis, or inverse probability weighting. As a minimum, the 
authors should adjust multivariate cox analysis not only with time period but also with other 
relevant covariates (i.e. donor risk index, MELD, recipient age, ecc.. ).  
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 i n 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.  
 
No 
 
Are you able to assess any statistics in the manuscript or would you recommend an  
additional st atistical 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 langu age in the manuscript:  
 
Acceptable  
 
Declaration 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 this  
manuscript, 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 f or 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 that 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 a uthors and, if the manuscript is accepted for publication, my named report  
including any attachments I upload 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