Review for 10.1186/s12876-016-0497-1 (2016)

Reviewer ’s report  
 
Title: Colonic polyp histopathology and location in a community -based sample of older adults  
 
Version: 0 Date: 22 Mar 2016 
 
Reviewer:  Mala  Pande  
 
Reviewer’s report:  
 
This is an interesting descriptive study focusing on the prevalence and distribution of colonic 
polyps by histopathology and location using pathology reports obtained from a regional 
laboratory.  
 
The strengths of the study are the large sample size, the detailed histopathology information from 
biopsy reports and a sample broadly representing community -based hospitals and surgical 
centers in the mid -Michigan region. Key independent variable s examined were age and gender.  
 
 
Comments (in order in which they appear in the article):  
 
1. Abstract:  
 
Results: Mentioning direction of association for age and gender for adenomas would be more 
meaningful than simply reporting that there was a statistically  significant difference by gender 
and age. Similarly, for sessile serrated adenomas, report whether positively or negatively 
associated with female gender.  
 
Conclusion: The statement "particularly in women and older adults" is not relevant the way the 
sente nce is framed because the study examined both genders and all relevant age distributions.  
 
 
2. Methods:  
 
It may be helpful to clarify whether or not the lab is CLIA certified or a research lab.  
 
 
Statistical Methods:  
 
It is mentioned that distribution of histop athology, morphology and location were compared by 
age and gender but the results (chi square, p values) are not presented in the tables. The authors 
could also use logistic regression for binary outcomes (left vs. right sided polyp, etc) and assess 
the as sociation of age and gender as independent variables by presenting odds ratios and 95% 
confidence intervals. May also like to consider age as a continuous variable in the logistic 
regression model as a covariate when assessing the influence of gender and v ice versa.  
 
3. Tables:  
 
Table 1: 2nd row, would be helpful to present mean and standard deviation overall and then by 
gender (male and female), instead of male/female at the end of the table. This will also allow 
presenting chi2 test p -values by gender for each age category.  
 
Table 2: Similarly, Table 2 would be more meaningful if the total n and %s are also stratified by 
gender by adding additional columns for male and female (n and %) and providing chi2 p -values 
across the single/multiple comparisons.  
 
Table 3: same as for Tables 1 and 2, add n and % by gender. This will help provide support for 
statements in the text such as sessile serrated polyps were more common in females (5.1%) than 
males (4.0%) (line 163) and lines 185 -186 (statistically significant d ifference in distribution by 
gender for location).  
 
Table 4: Could also provide logistic regression results stratified by gender. In the table 
formatting, if the first row is made 50 -59 years, with a referent OR of 1.0 (as per convention), 
then 50 -59 does n ot have to be repeated each time. The last row (female vs. male) can be 
removed and included by gender to the right of the table with males as the referent group.  
 
Table 5. Suggest reorganize by males and females in addition, as for other tables. Clarify wh at is 
cm in legend and label the column as Size (if that is what the cm refers to).  
 
 
4. Conclusion:  
 
Change "clinically" to "clinical" (line 198).  
 
Line 194: "more often in women at younger ages" provide support with data/numbers.  
 
Last line 227: should be "adenoma" instead of "carcinoma". Replace "most" with "more".  
 
 
5. Figures:  
 
Suggest combine Figures 1 and 2. Do gender comparison by age group using frequencies from 
tables. It would also be helpful to indicate statistically signific ant differences by using a * over 
the bar graphs or by some other means.Similarly, consider combining Figures 4 and 5.  
 
Are the methods appropriate and well described?  
If not, plea se 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 dat a 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 am able to assess the statistics  
 
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 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 c ontent of the 
manuscript?  
 
4. Have you received reimbursements, fees, funding, or salary from an organiz ation 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 a ny 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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