Reviewer's report
Title:Evaluation of a new fluorescence quantitative PCR test for diagnosing
Helicobacter pylori infection in children
Version: 2Date:7 November 2012
Reviewer: Thomas Wex
Reviewer's report:
The authors have addressed all issues appropriately, but I’m still not fully
convinced concerning the H. pylori-negative status. The authors used correctly
the clinical setting and differed between H. pylori-positive and the remaining
patients, subsequently defined as H. pylori-negative. Since no test available
today is a gold standard in regard to specificity and sensitivity, usually the “2 out
of three” rule is applied in clinical management. If a new test (like the studied
PCR) is evaluated, groups should be as “clean” as possible. The authors did this
for the H. pylori-positive by applying the rule mentioned above. It is well known
that due to medication with PPI, H2RA or for other reasons, bacterial load is
decreased, and therefore H. pylori might be not detected by all methods.
Therefore, the remaining group of patients includes also those with just one
positive test (RUT, breath test or histology).
The authors included additional patients (10+10) from the validation study that
meets the highest standard.
I suggest that the authors clearly define the H. pylori-negative status (on page 9)
as they did in the result section (page 10). For instance: “All other patients
(n=100) were assigned to the H. pylori-negative group. Note that among those,
xx patients were negative in all tests applied, and xx patients were positive for
just one test (histology: n=; RUT: n=; UBT: n=).
With respect to the specificity of the fqPCR it would be interesting to know
whether the additionally identified patients in the H. pylori-negative group (100
children) by the fq PCR had one positive test, or how many of those were
negative for all tests. I assume the specificity of the fqPCR will be even higher
than it is calculated from those without any positive test for H. pylori (as done for
the validation group).
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'
Reviewer's report
Title:Evaluation of a new fluorescence quantitative PCR test for diagnosing
Helicobacter pylori infection in children
Version: 2Date:7 November 2012
Reviewer: Thomas Wex
Reviewer's report:
The authors have addressed all issues appropriately, but I’m still not fully
convinced concerning the H. pylori-negative status. The authors used correctly
the clinical setting and differed between H. pylori-positive and the remaining
patients, subsequently defined as H. pylori-negative. Since no test available
today is a gold standard in regard to specificity and sensitivity, usually the “2 out
of three” rule is applied in clinical management. If a new test (like the studied
PCR) is evaluated, groups should be as “clean” as possible. The authors did this
for the H. pylori-positive by applying the rule mentioned above. It is well known
that due to medication with PPI, H2RA or for other reasons, bacterial load is
decreased, and therefore H. pylori might be not detected by all methods.
Therefore, the remaining group of patients includes also those with just one
positive test (RUT, breath test or histology).
The authors included additional patients (10+10) from the validation study that
meets the highest standard.
I suggest that the authors clearly define the H. pylori-negative status (on page 9)
as they did in the result section (page 10). For instance: “All other patients
(n=100) were assigned to the H. pylori-negative group. Note that among those,
xx patients were negative in all tests applied, and xx patients were positive for
just one test (histology: n=; RUT: n=; UBT: n=).
With respect to the specificity of the fqPCR it would be interesting to know
whether the additionally identified patients in the H. pylori-negative group (100
children) by the fq PCR had one positive test, or how many of those were
negative for all tests. I assume the specificity of the fqPCR will be even higher
than it is calculated from those without any positive test for H. pylori (as done for
the validation group).
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'
Please review this paper.
user
Reviewer's report
Title:Evaluation of a new fluorescence quantitative PCR test for diagnosing
Helicobacter pylori infection in children
Version: 2Date:7 November 2012
Reviewer: Thomas Wex
Reviewer's report:
The authors have addressed all issues appropriately, but I’m still not fully
convinced concerning the H. pylori-negative status. The authors used correctly
the clinical setting and differed between H. pylori-positive and the remaining
patients, subsequently defined as H. pylori-negative. Since no test available
today is a gold standard in regard to specificity and sensitivity, usually the “2 out
of three” rule is applied in clinical management. If a new test (like the studied
PCR) is evaluated, groups should be as “clean” as possible. The authors did this
for the H. pylori-positive by applying the rule mentioned above. It is well known
that due to medication with PPI, H2RA or for other reasons, bacterial load is
decreased, and therefore H. pylori might be not detected by all methods.
Therefore, the remaining group of patients includes also those with just one
positive test (RUT, breath test or histology).
The authors included additional patients (10+10) from the validation study that
meets the highest standard.
I suggest that the authors clearly define the H. pylori-negative status (on page 9)
as they did in the result section (page 10). For instance: “All other patients
(n=100) were assigned to the H. pylori-negative group. Note that among those,
xx patients were negative in all tests applied, and xx patients were positive for
just one test (histology: n=; RUT: n=; UBT: n=).
With respect to the specificity of the fqPCR it would be interesting to know
whether the additionally identified patients in the H. pylori-negative group (100
children) by the fq PCR had one positive test, or how many of those were
negative for all tests. I assume the specificity of the fqPCR will be even higher
than it is calculated from those without any positive test for H. pylori (as done for
the validation group).
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'
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