Reviewer's report
Title:Risk factors associated with symptomatic cholelithiasis in Taiwan: a
population-based study
Version: 1Date:24 June 2011
Reviewer: Gerardo Nava
Reviewer's report:
Summary:
Manuscript entitled: "Risk factors associated with symptomatic cholelithiasis in
Taiwan: a population-based study" examines disease factors associated to
symptomatic cholelithiasis based on a population-based and case-control study.
The relative risk was estimated by adjusted odds ratio (OR) using multivariate
logistic regression analysis. Authors concluded that the risk factors for
cholelithiasis in this population were obesity, hyperlipidemia, hepatitis B infection,
hepatitis C infection, and cirrhosis.
Critique:
This is a well written and nice study. However, there are a few issues that need
to be clarified by the authors.
Major Compulsory Revisions
1. Abstract
It is not clear how risk factors differed between Asian (this study) and West
populations.
2. Introduction
- Authors need to comment on possible biases or limitations of the methods used
for this study.
- This phrase is confusing and need clarification: "Cholelithiasis is known to affect
60-70% of America Indians and a proportionately smaller number individuals of
mixed Hispanic/American Indian background" Comments: authors need to
specify the ethnicity of this groups.
3. Methods
- Numerous studies (see example below) have shown that in outcomes that have
10% or more prevalence, the adjusted odds ratio derived from the logistic
regression do not approximate the risk ratio. In the present study some diseases
have an incidence >10%. Is it possible to correct the ORs or approximate to a
risk ratio from the adjusted odds ratios?
Zhang J, Yu KF. What's the relative risk? A method of correcting the odds ratio in
cohort studies of common outcomes. JAMA. 1998 Nov 18;280(19):1690-1.
- As presented, it is evident that all selected diseases in the present study
(obesity, hyperlipidemia, hepatitis B infection, hepatitis C infection, cirrhosis and
menopause) represent a risk factor (based on OR values) for symptomatic
cholelithiasis. Is it possible to perform additional analysis to rank the contribution
of each of these diseases? Is it possible to perform a multivariate analysis (PCoA
or NMDS, factor analysis, etc.) to establish the contribution of two or more
diseases?
4. Discussion
- The discussion is verbose and descriptive. Specifically, authors need to discuss
which factors contribute to the pigment stones found in the majority of gallstones
found in Asian populations. Also, they need to correlate and discuss their findings
using reports obtained from studies in different ethnic groups.
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:Risk factors associated with symptomatic cholelithiasis in Taiwan: a
population-based study
Version: 1Date:24 June 2011
Reviewer: Gerardo Nava
Reviewer's report:
Summary:
Manuscript entitled: "Risk factors associated with symptomatic cholelithiasis in
Taiwan: a population-based study" examines disease factors associated to
symptomatic cholelithiasis based on a population-based and case-control study.
The relative risk was estimated by adjusted odds ratio (OR) using multivariate
logistic regression analysis. Authors concluded that the risk factors for
cholelithiasis in this population were obesity, hyperlipidemia, hepatitis B infection,
hepatitis C infection, and cirrhosis.
Critique:
This is a well written and nice study. However, there are a few issues that need
to be clarified by the authors.
Major Compulsory Revisions
1. Abstract
It is not clear how risk factors differed between Asian (this study) and West
populations.
2. Introduction
- Authors need to comment on possible biases or limitations of the methods used
for this study.
- This phrase is confusing and need clarification: "Cholelithiasis is known to affect
60-70% of America Indians and a proportionately smaller number individuals of
mixed Hispanic/American Indian background" Comments: authors need to
specify the ethnicity of this groups.
3. Methods
- Numerous studies (see example below) have shown that in outcomes that have
10% or more prevalence, the adjusted odds ratio derived from the logistic
regression do not approximate the risk ratio. In the present study some diseases
have an incidence >10%. Is it possible to correct the ORs or approximate to a
risk ratio from the adjusted odds ratios?
Zhang J, Yu KF. What's the relative risk? A method of correcting the odds ratio in
cohort studies of common outcomes. JAMA. 1998 Nov 18;280(19):1690-1.
- As presented, it is evident that all selected diseases in the present study
(obesity, hyperlipidemia, hepatitis B infection, hepatitis C infection, cirrhosis and
menopause) represent a risk factor (based on OR values) for symptomatic
cholelithiasis. Is it possible to perform additional analysis to rank the contribution
of each of these diseases? Is it possible to perform a multivariate analysis (PCoA
or NMDS, factor analysis, etc.) to establish the contribution of two or more
diseases?
4. Discussion
- The discussion is verbose and descriptive. Specifically, authors need to discuss
which factors contribute to the pigment stones found in the majority of gallstones
found in Asian populations. Also, they need to correlate and discuss their findings
using reports obtained from studies in different ethnic groups.
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:Risk factors associated with symptomatic cholelithiasis in Taiwan: a
population-based study
Version: 1Date:24 June 2011
Reviewer: Gerardo Nava
Reviewer's report:
Summary:
Manuscript entitled: "Risk factors associated with symptomatic cholelithiasis in
Taiwan: a population-based study" examines disease factors associated to
symptomatic cholelithiasis based on a population-based and case-control study.
The relative risk was estimated by adjusted odds ratio (OR) using multivariate
logistic regression analysis. Authors concluded that the risk factors for
cholelithiasis in this population were obesity, hyperlipidemia, hepatitis B infection,
hepatitis C infection, and cirrhosis.
Critique:
This is a well written and nice study. However, there are a few issues that need
to be clarified by the authors.
Major Compulsory Revisions
1. Abstract
It is not clear how risk factors differed between Asian (this study) and West
populations.
2. Introduction
- Authors need to comment on possible biases or limitations of the methods used
for this study.
- This phrase is confusing and need clarification: "Cholelithiasis is known to affect
60-70% of America Indians and a proportionately smaller number individuals of
mixed Hispanic/American Indian background" Comments: authors need to
specify the ethnicity of this groups.
3. Methods
- Numerous studies (see example below) have shown that in outcomes that have
10% or more prevalence, the adjusted odds ratio derived from the logistic
regression do not approximate the risk ratio. In the present study some diseases
have an incidence >10%. Is it possible to correct the ORs or approximate to a
risk ratio from the adjusted odds ratios?
Zhang J, Yu KF. What's the relative risk? A method of correcting the odds ratio in
cohort studies of common outcomes. JAMA. 1998 Nov 18;280(19):1690-1.
- As presented, it is evident that all selected diseases in the present study
(obesity, hyperlipidemia, hepatitis B infection, hepatitis C infection, cirrhosis and
menopause) represent a risk factor (based on OR values) for symptomatic
cholelithiasis. Is it possible to perform additional analysis to rank the contribution
of each of these diseases? Is it possible to perform a multivariate analysis (PCoA
or NMDS, factor analysis, etc.) to establish the contribution of two or more
diseases?
4. Discussion
- The discussion is verbose and descriptive. Specifically, authors need to discuss
which factors contribute to the pigment stones found in the majority of gallstones
found in Asian populations. Also, they need to correlate and discuss their findings
using reports obtained from studies in different ethnic groups.
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