Kidney and Liver Predictors of Adults Hospitalized with COVID-19 Infection

Round 1

Reviewer 1 Report

Respectful greetings, I congratulate the authors for the paper, it seems to me that it contributes to the discussion of prognostic factors in patients with COVID 19 with severe clinical presentations, the design of the study being retrospective has important biases but the authors recognize the same, However, they have points in common with findings made by other research groups. Probably the point that makes extrapolation of the results more difficult is being only one institution, although the sample size is important. On the other hand, the findings suggest future development. of studies with prospective methodological designs that I believe must necessarily be the step to follow, the discussion seems well founded and the bibliographic review seems complete to me.

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Author Response

thank you very much for your review. 

Reviewer 2 Report

As indicated in Discussion, there is a significant age difference between cases and controls. Liver and kidney parameters may be influenced by age (The authors say: "...age could be a confounding parameter..."). This difference should be reduced by incorporating more controls with older adults.

Therefore, the results and conclusions are not consistent with the evidence and arguments presented.

Review the text in general. For example, COVID-19 is often written in lowercase letters.

It is necessary to increase the number of controls (preferably over 60 years old), so that it is comparable to the cases.

Author Response

thank you very much for your comment. I addressed them in the following attached file. 

Author Response File: Author Response.pdf

Reviewer 3 Report

The authors present a striking work whose objective was to investigate whether liver and kidney indexes can predict severity and mortality in COVID-19 patients. However, several details must be specified before it can be published. 

Methods, what is the study design? Cross-sectional, Longitudinal?

Methods, how the study sample was selected. Give more details.

Methods, what were the inclusion and exclusion criteria, respectively?

Methods, statistical analysis, were all the data normally distributed?  If not, what statistical tests were used?

Discussion, “For these reasons, we suggest carrying out a multi-center prospective trial, in a scale large enough to allow stratification of the results to address the limiting confounders.” A trial? Or rather a cohort design? What is the rationale? it is not clear because a trial involves randomization and intervention.

N/A.

Author Response

Thank you very much for your comments. I addressed this in the following attached file.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

There is a significant difference in age between cases and controls. Liver and kidney parameters can be influenced by age. Although this difference should be reduced by incorporating more controls with older adults, this is indicated in the discussion. 

There is a significant difference in age between cases and controls. Liver and kidney parameters can be influenced by age. Although this difference should be reduced by incorporating more controls with older adults, this is indicated in the discussion. 

Author Response

thank you very much for your reply. 

we addressed your important point in the discussion indeed. with extra analysis to address this difference. 

Reviewer 3 Report

The authors did an good job responding to my previous concerns.

1. Delete the period at the end of the title.

2. Methods, Age< 18 years old is not an exclusion criteria. According to the inclusion criteria, no patient under 18 years of age should have enrolled the study. 

3. Table 2, correct punctuation in footnote: replace "DM diabetes Mellitus" with "DM: diabetes Mellitus".  Correct the space between the comma and confidence interval "confidence interval , Std.Error Standard."

4. Table 3, correct the space between the comma and confidence interval "confidence interval , Std.Error Standard."

5. Table 4, correct the space between the comma and confidence interval "confidence interval , Std.Error Standard." Check the footnote font size.

6. Table 5, correct the space between the comma and confidence interval "confidence interval , Std.Error Standard." Check the footnote font size.

7. Table 6, correct the space between the comma and confidence interval "confidence interval , Std.Error Standard." Check the footnote font size.

Author Response

thank you very much for your review!

we corrected the manuscript following your instructions. 

• corrected point in the title.
• erased the space between comma and Confidence interval.
• adjusted the footnote size to the rest of manuscript.