Reviewer's report
Title:A comparison of diagnostic tests for lactose malabsorption - which one is
the best?
Version: 1Date:28 July 2009
Reviewer: Piero Vernia
Reviewer's report:
The study, although of some interest, is not new. In 1975 Necomer et al
published in NEJM a paper addressing the same problem. The test for genetic
defect is here used (and in a subset of patients only) whereas Newcomer
measured lactase activity. In both papers the serum glucose levels after a
lactose load were compared to the H2 breath test. Glucose levels, however, are
not any more used in adults, being less reliable that other techniques for the
diagnosis of lactose malabsorption /intolerance.
One main problem resides in the overall number of patients, which is low. The
patient selection, based on perceived milk intolerance (which is utterly unreliable)
and/or “non specific abdominal discomfort” is vague and debatable. Better
defined inclusion criteria, a larger patient series, and , possibly, exploring the
genetic defect in all patients would add much to this study.
The most interesting point of the paper is the demonstration that the sum of H2
plus CH4 x 2 has slightly better diagnostic properties as compared to H2.
Theoretically this approach is sound, H2 plus CH4 x 2 expressing more precisely
than H2 alone the overall production/ excretion of hydrogen. Nonetheless the
clinical use of methane is difficult as its concentration is highly variable, both in
fasting condition and after meals. The problem, in my opinion should be
discussed in detail by the authors.
Level of interest: An article of limited interest
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:A comparison of diagnostic tests for lactose malabsorption - which one is
the best?
Version: 1Date:28 July 2009
Reviewer: Piero Vernia
Reviewer's report:
The study, although of some interest, is not new. In 1975 Necomer et al
published in NEJM a paper addressing the same problem. The test for genetic
defect is here used (and in a subset of patients only) whereas Newcomer
measured lactase activity. In both papers the serum glucose levels after a
lactose load were compared to the H2 breath test. Glucose levels, however, are
not any more used in adults, being less reliable that other techniques for the
diagnosis of lactose malabsorption /intolerance.
One main problem resides in the overall number of patients, which is low. The
patient selection, based on perceived milk intolerance (which is utterly unreliable)
and/or “non specific abdominal discomfort” is vague and debatable. Better
defined inclusion criteria, a larger patient series, and , possibly, exploring the
genetic defect in all patients would add much to this study.
The most interesting point of the paper is the demonstration that the sum of H2
plus CH4 x 2 has slightly better diagnostic properties as compared to H2.
Theoretically this approach is sound, H2 plus CH4 x 2 expressing more precisely
than H2 alone the overall production/ excretion of hydrogen. Nonetheless the
clinical use of methane is difficult as its concentration is highly variable, both in
fasting condition and after meals. The problem, in my opinion should be
discussed in detail by the authors.
Level of interest: An article of limited interest
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:A comparison of diagnostic tests for lactose malabsorption - which one is
the best?
Version: 1Date:28 July 2009
Reviewer: Piero Vernia
Reviewer's report:
The study, although of some interest, is not new. In 1975 Necomer et al
published in NEJM a paper addressing the same problem. The test for genetic
defect is here used (and in a subset of patients only) whereas Newcomer
measured lactase activity. In both papers the serum glucose levels after a
lactose load were compared to the H2 breath test. Glucose levels, however, are
not any more used in adults, being less reliable that other techniques for the
diagnosis of lactose malabsorption /intolerance.
One main problem resides in the overall number of patients, which is low. The
patient selection, based on perceived milk intolerance (which is utterly unreliable)
and/or “non specific abdominal discomfort” is vague and debatable. Better
defined inclusion criteria, a larger patient series, and , possibly, exploring the
genetic defect in all patients would add much to this study.
The most interesting point of the paper is the demonstration that the sum of H2
plus CH4 x 2 has slightly better diagnostic properties as compared to H2.
Theoretically this approach is sound, H2 plus CH4 x 2 expressing more precisely
than H2 alone the overall production/ excretion of hydrogen. Nonetheless the
clinical use of methane is difficult as its concentration is highly variable, both in
fasting condition and after meals. The problem, in my opinion should be
discussed in detail by the authors.
Level of interest: An article of limited interest
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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