Reviewer's report
Title:Social disparities in the use of colonoscopy by primary care physicians in
Ontario
Version: 11Date:1 August 2011
Reviewer: Carl J Lombard
Reviewer's report:
The description of the ecological variables have been improved and this has
solved the understanding of the multiple regression model.
Some small comments on the multiple regression model.
1. the covariates have been categorised for ease of interpretation such as for
example median age of practice characteristic. The categories seems odd and
arbitrary. For median age for example we have 3 categories 50-59, 60-61, >=62
years. Why was this categorisation used especially a 10 year interval followed by
a 2 year interval followed by and open interval which should actually be 62-74.
Given this categorisation the rr for the less orlder age categories are .96 and .97
respectively. Are they really significantly different? This should be tested if you
are sticking to this categorisation.
This comment also holds for other coavariates such as % low income ( difference
between ,10,10-19?) % of life in rural location (please note that you are using
'lives': significant difference between <1 and 1-3?), %of labour force (<65 versus
65-69 - significantly different?)
2. For co-variates with more than two categories the p-values provided do not
reflect the overal significance of the variable - this overal p-values have not been
provided andit may be stated in the text that all such covariates in the model
were signficant.
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: Yes, and I have assessed the statistics in my report.
Declaration of competing interests:
'I declare that I have no competing interests'
Reviewer's report
Title:Social disparities in the use of colonoscopy by primary care physicians in
Ontario
Version: 11Date:1 August 2011
Reviewer: Carl J Lombard
Reviewer's report:
The description of the ecological variables have been improved and this has
solved the understanding of the multiple regression model.
Some small comments on the multiple regression model.
1. the covariates have been categorised for ease of interpretation such as for
example median age of practice characteristic. The categories seems odd and
arbitrary. For median age for example we have 3 categories 50-59, 60-61, >=62
years. Why was this categorisation used especially a 10 year interval followed by
a 2 year interval followed by and open interval which should actually be 62-74.
Given this categorisation the rr for the less orlder age categories are .96 and .97
respectively. Are they really significantly different? This should be tested if you
are sticking to this categorisation.
This comment also holds for other coavariates such as % low income ( difference
between ,10,10-19?) % of life in rural location (please note that you are using
'lives': significant difference between <1 and 1-3?), %of labour force (<65 versus
65-69 - significantly different?)
2. For co-variates with more than two categories the p-values provided do not
reflect the overal significance of the variable - this overal p-values have not been
provided andit may be stated in the text that all such covariates in the model
were signficant.
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: Yes, and I have assessed the statistics in my report.
Declaration of competing interests:
'I declare that I have no competing interests'
Please review this paper.
user
Reviewer's report
Title:Social disparities in the use of colonoscopy by primary care physicians in
Ontario
Version: 11Date:1 August 2011
Reviewer: Carl J Lombard
Reviewer's report:
The description of the ecological variables have been improved and this has
solved the understanding of the multiple regression model.
Some small comments on the multiple regression model.
1. the covariates have been categorised for ease of interpretation such as for
example median age of practice characteristic. The categories seems odd and
arbitrary. For median age for example we have 3 categories 50-59, 60-61, >=62
years. Why was this categorisation used especially a 10 year interval followed by
a 2 year interval followed by and open interval which should actually be 62-74.
Given this categorisation the rr for the less orlder age categories are .96 and .97
respectively. Are they really significantly different? This should be tested if you
are sticking to this categorisation.
This comment also holds for other coavariates such as % low income ( difference
between ,10,10-19?) % of life in rural location (please note that you are using
'lives': significant difference between <1 and 1-3?), %of labour force (<65 versus
65-69 - significantly different?)
2. For co-variates with more than two categories the p-values provided do not
reflect the overal significance of the variable - this overal p-values have not been
provided andit may be stated in the text that all such covariates in the model
were signficant.
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: Yes, and I have assessed the statistics in my report.
Declaration of competing interests:
'I declare that I have no competing interests'
assistant