Reviewer's report
Title:Validation of the FIB4 index in a Japanese nonalcoholic fatty liver disease
population
Version: 1Date:30 August 2011
Reviewer: Ancha Baranova
Reviewer's report:
This is a review of the paper “Validation if FIB4 index in a Japanese nonalcoholic
fatty liver disease population” by Yoshio Sumida and co-authors.
This paper validates the performance of noninvasive marker FIB4 (based on
ALT, AST, age and platelet counts) for predicting advanced liver fibrosis in a
Japanese cohort with NAFLD. AUROC for FIB4 index was compared with six
other noninvasive markers. The authors show FIB4 index to be superior
compared to others with a high negative predictive power and FIB4 index can be
established as a relatively inexpensive method correlating with stage of fibrosis in
adult subjects with NAFLD. This study this study was restricted to Japanese
population with NAFLD and the utility of FIB4 index needs to be tested on a wider
population to be established as a predictor for advanced liver fibrosis in adult
subjects with NAFLD.
The FIB4 index is based in ALT and AST values, in addition to age and platelet
count. Studies have reported that not all patients with NAFLD have elevated ALT
and AST values ( http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2670414/ ).
Authors should discuss the impact of normal liver enzyme levels on utility of FIB4
index to predict advanced fibrosis in such individuals.
Also, all tests used for cross-comparisons were centered around AST, ALT and
platelets e.g. APRI index. It will be more valuable if some panel based on soluble
serum markers was included into the comparison. (at least in discussion section).
Another major point is prevalence of NAFLD in patients with HCV (
http://www.ncbi.nlm.nih.gov/pubmed/14499789 ). I understood that these patients
were excluded from current study. However, authors should address if FIB4
index performs differently in such cohorts in the discussion.
Minor comments
1. Rephrase: “demonstrated that performance characteristics for the diagnosis of
advanced fibrosis in NAFLD are better than those of other similar panels that do
not require additional testing, and comparable to several others that do require
additional tests.”
2. Introduction: In this study, we therefore aimed ……predicting ‘significant
fibrosis’. Did the authors mean ‘advanced fibrosis’?
3. Inconsistent definition - Methods: Diagnosis of NAFLD was based on the
following criteria (1) liver biopsy showing steatosis in at least 5% hepatocytes.
However, under histological evaluation fatty liver was defined as the presence of
> 5% steatosis (is it 5% of the area?).
4. need to indicate what software (vendor) was employed for regression analysis
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 the FIB4 index in a Japanese nonalcoholic fatty liver disease
population
Version: 1Date:30 August 2011
Reviewer: Ancha Baranova
Reviewer's report:
This is a review of the paper “Validation if FIB4 index in a Japanese nonalcoholic
fatty liver disease population” by Yoshio Sumida and co-authors.
This paper validates the performance of noninvasive marker FIB4 (based on
ALT, AST, age and platelet counts) for predicting advanced liver fibrosis in a
Japanese cohort with NAFLD. AUROC for FIB4 index was compared with six
other noninvasive markers. The authors show FIB4 index to be superior
compared to others with a high negative predictive power and FIB4 index can be
established as a relatively inexpensive method correlating with stage of fibrosis in
adult subjects with NAFLD. This study this study was restricted to Japanese
population with NAFLD and the utility of FIB4 index needs to be tested on a wider
population to be established as a predictor for advanced liver fibrosis in adult
subjects with NAFLD.
The FIB4 index is based in ALT and AST values, in addition to age and platelet
count. Studies have reported that not all patients with NAFLD have elevated ALT
and AST values ( http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2670414/ ).
Authors should discuss the impact of normal liver enzyme levels on utility of FIB4
index to predict advanced fibrosis in such individuals.
Also, all tests used for cross-comparisons were centered around AST, ALT and
platelets e.g. APRI index. It will be more valuable if some panel based on soluble
serum markers was included into the comparison. (at least in discussion section).
Another major point is prevalence of NAFLD in patients with HCV (
http://www.ncbi.nlm.nih.gov/pubmed/14499789 ). I understood that these patients
were excluded from current study. However, authors should address if FIB4
index performs differently in such cohorts in the discussion.
Minor comments
1. Rephrase: “demonstrated that performance characteristics for the diagnosis of
advanced fibrosis in NAFLD are better than those of other similar panels that do
not require additional testing, and comparable to several others that do require
additional tests.”
2. Introduction: In this study, we therefore aimed ……predicting ‘significant
fibrosis’. Did the authors mean ‘advanced fibrosis’?
3. Inconsistent definition - Methods: Diagnosis of NAFLD was based on the
following criteria (1) liver biopsy showing steatosis in at least 5% hepatocytes.
However, under histological evaluation fatty liver was defined as the presence of
> 5% steatosis (is it 5% of the area?).
4. need to indicate what software (vendor) was employed for regression analysis
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 the FIB4 index in a Japanese nonalcoholic fatty liver disease
population
Version: 1Date:30 August 2011
Reviewer: Ancha Baranova
Reviewer's report:
This is a review of the paper “Validation if FIB4 index in a Japanese nonalcoholic
fatty liver disease population” by Yoshio Sumida and co-authors.
This paper validates the performance of noninvasive marker FIB4 (based on
ALT, AST, age and platelet counts) for predicting advanced liver fibrosis in a
Japanese cohort with NAFLD. AUROC for FIB4 index was compared with six
other noninvasive markers. The authors show FIB4 index to be superior
compared to others with a high negative predictive power and FIB4 index can be
established as a relatively inexpensive method correlating with stage of fibrosis in
adult subjects with NAFLD. This study this study was restricted to Japanese
population with NAFLD and the utility of FIB4 index needs to be tested on a wider
population to be established as a predictor for advanced liver fibrosis in adult
subjects with NAFLD.
The FIB4 index is based in ALT and AST values, in addition to age and platelet
count. Studies have reported that not all patients with NAFLD have elevated ALT
and AST values ( http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2670414/ ).
Authors should discuss the impact of normal liver enzyme levels on utility of FIB4
index to predict advanced fibrosis in such individuals.
Also, all tests used for cross-comparisons were centered around AST, ALT and
platelets e.g. APRI index. It will be more valuable if some panel based on soluble
serum markers was included into the comparison. (at least in discussion section).
Another major point is prevalence of NAFLD in patients with HCV (
http://www.ncbi.nlm.nih.gov/pubmed/14499789 ). I understood that these patients
were excluded from current study. However, authors should address if FIB4
index performs differently in such cohorts in the discussion.
Minor comments
1. Rephrase: “demonstrated that performance characteristics for the diagnosis of
advanced fibrosis in NAFLD are better than those of other similar panels that do
not require additional testing, and comparable to several others that do require
additional tests.”
2. Introduction: In this study, we therefore aimed ……predicting ‘significant
fibrosis’. Did the authors mean ‘advanced fibrosis’?
3. Inconsistent definition - Methods: Diagnosis of NAFLD was based on the
following criteria (1) liver biopsy showing steatosis in at least 5% hepatocytes.
However, under histological evaluation fatty liver was defined as the presence of
> 5% steatosis (is it 5% of the area?).
4. need to indicate what software (vendor) was employed for regression analysis
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