Review for 10.1186/s12876-017-0642-5 (2017)

Reviewer ’s report  
 
Title: Risk of colorectal cancer among immigrants to Ontario, Canada  
 
Version: 0 Date: 23 Mar 2017  
 
Reviewer: Monica Robotin  
 
Reviewer's report:  
 
This is an interesting paper, adding to the body of epidemiological knowledge about variations in 
cancer risk in migrant populations.  
I have a few comments and queries:  
1. The Background section states that the study aimed to "inform the CCC of the variability of 
risk by origin of immigrants and the potential relative significance of low screening in 
participants by origin of immigrants". This needs rephrasing for clarity, as does the 
paragraph referring to s creening rates in migrants in the Discussion. While it is likely that 
screening rates in migrants are lower, the Discussion needs to refer to the published 
literature to support this contention.  
2. Were the authors able to tease out whether the CRC risk was different for people who 
underwent screening, compared to those who did not?  
3. The Discussion section sells the paper short and needs to be augmented and the contribution 
of this study highlig hted.  
4. The sentence about data from British Columbia (preferably the entire paragraph) needs 
rephrasing and include an interpretation of the cited statistics.  
5. Given the brevity of the paper, it includes a disproportionate number of tables and figures . 
Perhaps Figures 3 and 4 could be included as Appendices.  
 
Small points:  
1. The first paragraph in the Background section needs rephrasing for clarity.  
2. In the Results section - countries of birth appear in Table 2, not Table 1  
3. Spaces and typos on Pa ge 6 comparedto male; by the Kaplan -Meier method the risk…  
 
 
Are the methods appropriate and well describ ed? 
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 supp orted 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 recomme nded, 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 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 p ublication 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 that I have no competing interests'  
 
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