Reviewer ’s report  
Title: Intrahepatic cholestasis of pregnancy and associated causes of death: a cohort study  with 
follow -up of 27 -46 years  
 
Version: 1 Date: 21 Dec 2017  
 
Reviewer: Olof Stephansson  
 
Reviewer's report:  
Review of manuscript BMWH -D-17-00280_R1  
Thank you for the opportunity to review this manuscript. This is a study on the association 
between ICP and causes of death. In general, data is of high quality with almost complete follow -
up for women with ICP and population controls. The study reports an increase in mortality from 
gastrointestinal diseases among women with a history of ICP compared with contro ls. 
 
General comments  
1. The aim of the study should also include overall mortality as well as specific causes of death 
in women with ICP compared with controls. It seems natural to start with overall mortality 
in women with ICP compared to population contr ols and then take this further into specific 
causes. The main finding would be that ICP women do not have an increased overall 
mortality, and in my view, this should be included in the conclusion of the abstract and the 
discussion.  
2. Would it be possible to present a Kaplan Meyer graph for overall mortality for ICP women 
and controls?  
3. Is there any data on parity, and could this influence the overall and specific mortality?  
4. The increase in gastrointestinal deaths, could it be attributed to existing li ver disease at the 
time of ICP diagnosis. Please discuss this possibility further in the Discussion of the 
manuscript.  
 
 
 
Specific comments  
1. I think it should be stated in the introduction that ICP is characterized by otherwise 
unexplained pruritus with ele vated bile acids and/or transaminases. I.e. in the absence of 
other liver disease.  
2. In what proportion was it not possible to verify the ICP diagnosis?  
3. Is it possible to provide statistics with p -values in Table 1 for comparison of the age 
distribution?  
4. I think the Discussion could be better structured if the authors include a separate section of 
strengths and limitations of the study.  
 
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.  
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 manus cript or would you recommend an 
additional statistical review?  
If an additional statistical review is recommended, please speci fy 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 manuscri pt: 
Accept able 
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, fundi ng, 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 t hat may in any way gain or lose 
financially from t he 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 com peting interests in relation to this paper?  
If you can an swer 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  
 
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