Reviewer's report
Title:Validation of a survey methodology for gastroesophageal reflux disease in
China
Version: 2Date:15 June 2008
Reviewer: Vic Velanovich
Reviewer's report:
Overall, this is a very well done study and the authors should be congradulated.
Major Compulsory Revisions
1. p. 8, "Questionnaires" section. The authors need to state a rationale for why
these instruments were chosen for study. Why other GERD-related instruments
were excluded. It seems that these instruments assess slightly different aspects
of how GERD affects quality of life, therefore, they may not be interchangable. I
think that a table or figure showing the complete questionnaires so that the
reader can see what is being asked of the patient would be helpful.
2. p. 10, last two sentences. How was it determine that the subjects considered
the questions "relevant and clear." The authors discuss in a few places in the
manuscript the cultural nuances of Chinese patients related symptoms to GERD.
Was a qualitative analysis done? How much of the original language of the
instruments had to be modified to order to gain meaning in Mandarin? This is no
trivial issue as your factor analysis of the QOLRAD showed poor construct
validity and translation issues may play a role in this.
3. p. 19. I think that the authors have done a great service to researchers wanting
to study GERD in Madarin-speaking patients, therefore, how are the authors
going to make available there translations of these instruments? Perhaps these
translations should be published in this paper.
Minor Essential Revisions
1. p. 11, "Statistical Analysis" section. What is the rationale "50%" of item
completion used as cutoff to include or exclude demension scores from analysis?
Morevoer, in the results section, these is no mention of the frequency of missing
items, and if this varied by region.
2. p. 16, 1st full para. Why does not the factor analysis of the QOLRAD deserve
its own table?
3. p. 16, "Convergent validity" section. In linear regression analysis, correlations
are not "statistically significant." What is statistically significant is that the slope of
the regression line is different from 0. A minor point, but it speaks to an
understanding of the data analysis used.
Discretionary Revisions
1. p. 17, last sentence of 1st incomplete para. The fact that facilitators considered
some items difficult to explain speaks to a problem of practicality. That is, not
matter how good an instruments validity and reliability is, if it is impractical to
administer, then it will not be used by other researchers. Can the authors
comment?
2. p. 17, last sentence of 1st full paragraph. Are the authors suggesting or
recommending that trained facilitators always be used when trying to administer
these instruments to Mandarin-speaking patients?
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:Validation of a survey methodology for gastroesophageal reflux disease in
China
Version: 2Date:15 June 2008
Reviewer: Vic Velanovich
Reviewer's report:
Overall, this is a very well done study and the authors should be congradulated.
Major Compulsory Revisions
1. p. 8, "Questionnaires" section. The authors need to state a rationale for why
these instruments were chosen for study. Why other GERD-related instruments
were excluded. It seems that these instruments assess slightly different aspects
of how GERD affects quality of life, therefore, they may not be interchangable. I
think that a table or figure showing the complete questionnaires so that the
reader can see what is being asked of the patient would be helpful.
2. p. 10, last two sentences. How was it determine that the subjects considered
the questions "relevant and clear." The authors discuss in a few places in the
manuscript the cultural nuances of Chinese patients related symptoms to GERD.
Was a qualitative analysis done? How much of the original language of the
instruments had to be modified to order to gain meaning in Mandarin? This is no
trivial issue as your factor analysis of the QOLRAD showed poor construct
validity and translation issues may play a role in this.
3. p. 19. I think that the authors have done a great service to researchers wanting
to study GERD in Madarin-speaking patients, therefore, how are the authors
going to make available there translations of these instruments? Perhaps these
translations should be published in this paper.
Minor Essential Revisions
1. p. 11, "Statistical Analysis" section. What is the rationale "50%" of item
completion used as cutoff to include or exclude demension scores from analysis?
Morevoer, in the results section, these is no mention of the frequency of missing
items, and if this varied by region.
2. p. 16, 1st full para. Why does not the factor analysis of the QOLRAD deserve
its own table?
3. p. 16, "Convergent validity" section. In linear regression analysis, correlations
are not "statistically significant." What is statistically significant is that the slope of
the regression line is different from 0. A minor point, but it speaks to an
understanding of the data analysis used.
Discretionary Revisions
1. p. 17, last sentence of 1st incomplete para. The fact that facilitators considered
some items difficult to explain speaks to a problem of practicality. That is, not
matter how good an instruments validity and reliability is, if it is impractical to
administer, then it will not be used by other researchers. Can the authors
comment?
2. p. 17, last sentence of 1st full paragraph. Are the authors suggesting or
recommending that trained facilitators always be used when trying to administer
these instruments to Mandarin-speaking patients?
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:Validation of a survey methodology for gastroesophageal reflux disease in
China
Version: 2Date:15 June 2008
Reviewer: Vic Velanovich
Reviewer's report:
Overall, this is a very well done study and the authors should be congradulated.
Major Compulsory Revisions
1. p. 8, "Questionnaires" section. The authors need to state a rationale for why
these instruments were chosen for study. Why other GERD-related instruments
were excluded. It seems that these instruments assess slightly different aspects
of how GERD affects quality of life, therefore, they may not be interchangable. I
think that a table or figure showing the complete questionnaires so that the
reader can see what is being asked of the patient would be helpful.
2. p. 10, last two sentences. How was it determine that the subjects considered
the questions "relevant and clear." The authors discuss in a few places in the
manuscript the cultural nuances of Chinese patients related symptoms to GERD.
Was a qualitative analysis done? How much of the original language of the
instruments had to be modified to order to gain meaning in Mandarin? This is no
trivial issue as your factor analysis of the QOLRAD showed poor construct
validity and translation issues may play a role in this.
3. p. 19. I think that the authors have done a great service to researchers wanting
to study GERD in Madarin-speaking patients, therefore, how are the authors
going to make available there translations of these instruments? Perhaps these
translations should be published in this paper.
Minor Essential Revisions
1. p. 11, "Statistical Analysis" section. What is the rationale "50%" of item
completion used as cutoff to include or exclude demension scores from analysis?
Morevoer, in the results section, these is no mention of the frequency of missing
items, and if this varied by region.
2. p. 16, 1st full para. Why does not the factor analysis of the QOLRAD deserve
its own table?
3. p. 16, "Convergent validity" section. In linear regression analysis, correlations
are not "statistically significant." What is statistically significant is that the slope of
the regression line is different from 0. A minor point, but it speaks to an
understanding of the data analysis used.
Discretionary Revisions
1. p. 17, last sentence of 1st incomplete para. The fact that facilitators considered
some items difficult to explain speaks to a problem of practicality. That is, not
matter how good an instruments validity and reliability is, if it is impractical to
administer, then it will not be used by other researchers. Can the authors
comment?
2. p. 17, last sentence of 1st full paragraph. Are the authors suggesting or
recommending that trained facilitators always be used when trying to administer
these instruments to Mandarin-speaking patients?
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