Reviewer's report
Title:Psychopathological features of irritable bowel syndrome patients with and
without functional dyspepsia: a cross sectional study
Version: 2Date:24 November 2010
Reviewer: Michael Crowell
Reviewer's report:
Manuscript ID: BMC MS 2070463711382080
Title: Psychopathological features of irritable bowel syndrome patients with and
without functional dyspepsia: a cross sectional study
Dear Editor,
The paper has been revised and improved from the original version. The authors
have adequately addressed my concerns related to design and statistical issues
except for one point. Point 5 of my previous review raised the concern that the
type I error was inflated due to multiple testing of the SCL90 subscales without
correction or specifically stating that the alpha level was not corrected for multiple
testing. The study evaluated differences between IBS and IBS+FD for 10 scales
resulting in a dramatic inflation of type I error rate. With 10 separate statistical
tests the potential to find a p-value less than 0.05 is greater than 40% provided
that the endpoints are not highly correlated. The authors should be more specific
about their primary hypothesis and use the GSI at 0.05 and adjust the subscales
or at least point out that no adjustments were made and that type I error rate was
inflated. Given the size of most of the p-values these adjustments are unlikely to
change the outcome of the study, but should be reported appropriately.
My concern can be readily addressed, at which time I would recommend that the
paper be accepted at the discretion of the managing Editors.
Thank You,
Michael D. Crowell, Ph.D., FACG, AGAF
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:Psychopathological features of irritable bowel syndrome patients with and
without functional dyspepsia: a cross sectional study
Version: 2Date:24 November 2010
Reviewer: Michael Crowell
Reviewer's report:
Manuscript ID: BMC MS 2070463711382080
Title: Psychopathological features of irritable bowel syndrome patients with and
without functional dyspepsia: a cross sectional study
Dear Editor,
The paper has been revised and improved from the original version. The authors
have adequately addressed my concerns related to design and statistical issues
except for one point. Point 5 of my previous review raised the concern that the
type I error was inflated due to multiple testing of the SCL90 subscales without
correction or specifically stating that the alpha level was not corrected for multiple
testing. The study evaluated differences between IBS and IBS+FD for 10 scales
resulting in a dramatic inflation of type I error rate. With 10 separate statistical
tests the potential to find a p-value less than 0.05 is greater than 40% provided
that the endpoints are not highly correlated. The authors should be more specific
about their primary hypothesis and use the GSI at 0.05 and adjust the subscales
or at least point out that no adjustments were made and that type I error rate was
inflated. Given the size of most of the p-values these adjustments are unlikely to
change the outcome of the study, but should be reported appropriately.
My concern can be readily addressed, at which time I would recommend that the
paper be accepted at the discretion of the managing Editors.
Thank You,
Michael D. Crowell, Ph.D., FACG, AGAF
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:Psychopathological features of irritable bowel syndrome patients with and
without functional dyspepsia: a cross sectional study
Version: 2Date:24 November 2010
Reviewer: Michael Crowell
Reviewer's report:
Manuscript ID: BMC MS 2070463711382080
Title: Psychopathological features of irritable bowel syndrome patients with and
without functional dyspepsia: a cross sectional study
Dear Editor,
The paper has been revised and improved from the original version. The authors
have adequately addressed my concerns related to design and statistical issues
except for one point. Point 5 of my previous review raised the concern that the
type I error was inflated due to multiple testing of the SCL90 subscales without
correction or specifically stating that the alpha level was not corrected for multiple
testing. The study evaluated differences between IBS and IBS+FD for 10 scales
resulting in a dramatic inflation of type I error rate. With 10 separate statistical
tests the potential to find a p-value less than 0.05 is greater than 40% provided
that the endpoints are not highly correlated. The authors should be more specific
about their primary hypothesis and use the GSI at 0.05 and adjust the subscales
or at least point out that no adjustments were made and that type I error rate was
inflated. Given the size of most of the p-values these adjustments are unlikely to
change the outcome of the study, but should be reported appropriately.
My concern can be readily addressed, at which time I would recommend that the
paper be accepted at the discretion of the managing Editors.
Thank You,
Michael D. Crowell, Ph.D., FACG, AGAF
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