Review for 10.1186/s12876-014-0196-8 (2014)

Reviewer's report
Title:Adenoma detection rates in an opportunistic screening colonoscopy
program in Iran, a country with rising colorectal cancer incidence
Version:1Date:8 September 2014
Reviewer: Joshua Melson
Reviewer's report:
The study is a retrospective review of an opportunistic screening colonoscopy
program from an Iranian center over a 7-year period. Thirteen endoscopists
performed the procedures. The findings of poor preparation, age and male
gender as predictors of adenoma detection rate (ADR) are in line with findings
from numerous North American and European studies. There is limited data from
this region on screening programs in regards to efficacy and ADR and this data
could be somewhat informative in guiding program screening efforts in the future.
The following issues should be addressed.
Major Revision
I. Distribution of procedures by colonoscopist: the distribution of the procedures
by the colonoscopists is not described. There is a somewhat low cecal intubation
rate amongst the cohort even when poor bowel preparations are excluded of
90% and it would be informative to know if this was present in just a few or many
of the cohort of colonoscopists.
2. The rising incidence of colorectal cancer incidence in Iran. While this is not a
crucial point to the design of the study it is mentioned multiple times (in
background and discussion). The cited papers relevant to this claim are not
particular to Iran and CRC rates of nearby countries or Iran itself are not
mentioned. While the referenced Jemal et al. paper does show worldwide
incidence to be increasing in developing countries data which shows or suggests
rising incidence in this region of CRC would be informative.
Along that line what is the current capacity for colonoscopy for screening in Iran.
Is most colonoscopy done by surgeons, gastroenterologists, primary care. Is
there a defined training or credentialing program completion to practice
colonoscopy. For those not familiar with the healthcare structure in Iran this could
be informative.
3. Patient selection and Uptake of Colonoscopy for screening- Over a 7 year
period only 713 patients undergo colonoscopy for screening that make inclusion
criteria. A comment on why the uptake of colonoscopy is presumably low would
be appreciated. If data were available on the rate of completion of colonoscopy in
relation to all those offered screening would be even of more interest. Is there
social or payer coverage leading to this presumably low rate of completion? This
could greatly strengthen the paper. If uptake of offered procedure is markedly low
then this contextualizes that acceptance of screening is an even greater issue
than technical considerations for screening.
The exclusion of “symptomatic individuals” should be further described, for
instance would a patient with a newfound iron deficiency anemia be considered
symptomatic in this cohort?
4. Intubation rates:
The cecal intubation rates are quite low in relation to western gastroenterologist
norms (82.75%). A higher rate of cecal intubation as expected was present in
those with fair or better prep. However, even with adequate preparations the
rates of relatively low intubation rates (90%) deserves some comment whether
this is sedation related, operator or colonoscope related.
5. Bowel preparation:
The rates of poor preparations are very high (37%) far in excess of what would
be expected even among a low SES cohort in North American and European
reports and this deserves further comment. Some further description of the
communication process of providers to patients regarding preparation
instructions would be helpful to inform on this markedly high rate of poor
preparation.
6. Polyp and Advanced ADR rates: The markedly high advanced ADR merits
some discussion and questions whether there is some initial selection bias to a
cohort with advanced lesions or if an excellent detector or two of advanced
lesions is over represented in procedure volume. How are serrated adenomas
considered in relation to advanced ADR? I would recommend serrated adenoma
detection rate also be reported as a separate endpoint. If the advanced adenoma
rate here include sessile serrated adenoma less than 1 cm to explain this
markedly high rate, I would suggest removing those serrated adenomas that are
less than 1 cm from the advanced group as these are not considered advanced
based on USMTF.
Minor Revision
6. Colonoscopies: What is listed for Pentax and Olympus are the video processor
types rather than the colonoscopes themselves. The actual colonoscope model
types are needed.
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a statistician.
Declaration of competing interests:
I declare that I have no competing interests