Title: Helicobacter pylori infection is not an independent risk factor of non-alcoholic fatty liver
disease in China
Version: 4 Date: 31 Oct 2021
Reviewer's report:
The authors investigated the association between H pylori and NAFLD. While the results are
interesting, I have some questions and comments.
1. In the multivariate models, the authors failed to account for multicollinearity. For example,
total cholesterol and triglyceride levels or IFG and HbA1c. These exert a high amount of
influence on each other and should not be included in the same model unless they are shown
to be completely independent.
2. Table 1 suggests that metabolic factors (cholesterol, HbA1c, BP, etc) are indeed associated
with HP. However, due to the cross-sectional nature of the study, it is difficult to determine
whether HP is the culprit behind these differences. As the study numbers seem sufficient, I
suggest a further analysis using propensity matching to account for the more influential factors
such as BP and BMI, etc.
3. H pylori is not always in italics while some are. Please unify according to BMC guidelines.
Also, some are  reported as HP while some use H. pylori. Please unify these as well.
Title: Helicobacter pylori infection is not an independent risk factor of non-alcoholic fatty liver
disease in China
Version: 4 Date: 31 Oct 2021
Reviewer's report:
The authors investigated the association between H pylori and NAFLD. While the results are
interesting, I have some questions and comments.
1. In the multivariate models, the authors failed to account for multicollinearity. For example,
total cholesterol and triglyceride levels or IFG and HbA1c. These exert a high amount of
influence on each other and should not be included in the same model unless they are shown
to be completely independent.
2. Table 1 suggests that metabolic factors (cholesterol, HbA1c, BP, etc) are indeed associated
with HP. However, due to the cross-sectional nature of the study, it is difficult to determine
whether HP is the culprit behind these differences. As the study numbers seem sufficient, I
suggest a further analysis using propensity matching to account for the more influential factors
such as BP and BMI, etc.
3. H pylori is not always in italics while some are. Please unify according to BMC guidelines.
Also, some are  reported as HP while some use H. pylori. Please unify these as well.
Please review this paper.
user
Title: Helicobacter pylori infection is not an independent risk factor of non-alcoholic fatty liver
disease in China
Version: 4 Date: 31 Oct 2021
Reviewer's report:
The authors investigated the association between H pylori and NAFLD. While the results are
interesting, I have some questions and comments.
1. In the multivariate models, the authors failed to account for multicollinearity. For example,
total cholesterol and triglyceride levels or IFG and HbA1c. These exert a high amount of
influence on each other and should not be included in the same model unless they are shown
to be completely independent.
2. Table 1 suggests that metabolic factors (cholesterol, HbA1c, BP, etc) are indeed associated
with HP. However, due to the cross-sectional nature of the study, it is difficult to determine
whether HP is the culprit behind these differences. As the study numbers seem sufficient, I
suggest a further analysis using propensity matching to account for the more influential factors
such as BP and BMI, etc.
3. H pylori is not always in italics while some are. Please unify according to BMC guidelines.
Also, some are  reported as HP while some use H. pylori. Please unify these as well.
assistant