Review for 10.1186/s12876-018-0924-6 (2019)

Reviewer ’s report  
 
Title:  Predictive Modeling of Disease Burden in Adult -Onset Ulcerative Colitis Using Health 
Administrative Data  
 
Version: 0 Date: 28 Nov 2018 
 
Reviewer:  Ammar Hassanzadeh Keshteli  
 
Reviewer’s report:  
 
In this study, Murthy et al. used health administrative data to predict disease burden in adult 
ulcerative colitis patients living in Ont ario, Canada. The authors found that a model based on a 
group of health administrative data could discriminate levels of UC burden at diagnosis. The 
study is well designed and the results are interesting. However, there are some concerns that 
need to be ad dressed by the authors.  
 
It seems that data from all 587 participants were used to generate the models and performance of 
the models were assessed in these 587 patients. I am wondering why the authors did not split 
their participants into two sets: a trai ning set to develop the models and a validation set to verify 
the performance of the generated models. This way they could potentially investigate the 
generalizability of their models to other populations.  
 
Introduction: The study rationale and objectives  should be explained in more details.  
 
It is not clear why the performance of the models to predict disease burden was superior to their 
performance in predicting UC extent and UC activity. Please discuss about this finding and its 
importance in more deta ils.  
 
Lines 181 and 182 should be rewritten (as it is not easy to understand in its current format). 
Apparently, 1 -year definitions were more associated with outcomes in comparison to 2 - and 3 - 
year definitions. Please discuss about this finding in the discussio n section.  
 
Among the 20 variables listed in Table 1, which ones were used in the final models? Were their 
role in the final models equal? Please clarify.  
 
Please define "disease burden" in the methods section of abstract.  
 
Line 80: linkagelinkage -> linkage  
 
Line 81: toto -> to 
 
Line 101: Physician'sphysician's -> physician's  
 
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.  
 
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 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 public ation 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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on my report to the authors and, if the manuscript is accepted for publication, my named report 
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