Long COVID Is Associated with Severe Cognitive Limitations Among U.S. Adults

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Thank you for the opportunity to review this important article titled "Long COVID is Associated with Severe Cognitive Limitations Among U.S. Adults." Below are my comments for improvement:

Major Revisions:

1. Consistency in Terminology: Use COVID-19 to refer to acute illness instead of COVID to differentiate it from long COVID.
2. Introduction (Page 1, Second Paragraph): Define cognitive impairment before discussing its consequences on patients’ health and its impact on caregivers.
3. Page 2, Line 53: Cite the publication year for the study by Zhao et al.
4. Page 2, Line 57: Provide the publication year for the UK study.
5. Page 2, Line 61: add (U.S.) after United States to maintain consistency with its abbreviation throughout the text.
6. Page 2, Line 84: Include a reference for the Washington Group Short Form Disability Questions scale.
7. Page 2, Line 86: Clarify the rationale for the indicator variable measuring severe cognitive limitations. How does this classification accurately capture severity? "We created an indicator variable for severe cognitive limitation (Yes/No) by combining adults who responded ‘no’ or ‘yes, with some difficulty’ into one group, and those who responded ‘yes, with a lot of difficulty’ or ‘cannot do at all’ into another group."
8. Page 3, Line 94: Provide a reference for Federal Poverty Level (FPL).
9. Page 3, Line 98: In the Statistical Analyses section, specify the significance level used and briefly explain Rao-Scott chi-square tests.
10. Table 1: Report the p-value for gender.
11. Age Group Analysis: Why does the 18–34 years age category have a higher weighted percentage (wt%) in both long COVID and severe cognitive limitations? Also, why were key variables such as COVID-19 severity at acute illness, hospitalization status, ICU admission, and COVID-19 treatment not included? These factors are potential confounders that should be considered in the analysis.
12. Logistic Regression: In the model, individuals aged 75+ years (AOR = 1.40, 95% CI = 1.19–1.64) were analyzed. What was the reference group? If it was compared to the 18–34 years group, the findings seem inconsistent with the bivariate analysis. Please clarify.
13. Page 8, Line 152: "We found that 15.1% of adults reported experiencing long COVID, representing approximately 29.4 million adults." This finding is missing from the Results section and should be visually represented, such as in a graph.
14. Page 9, Line 158: Define MPES.
15. Address logistic regression findings, including why the 18–34 years age group is highly affected. Additionally, Hyperbaric Oxygen Therapy (HBOT) is mentioned, but there is no relevant data in the study to compare—please clarify its inclusion.
16. If cognitive impairment is common in older adults, why does the study show lower rates of impairment post-COVID-19 infection? This requires further explanation.

 

 

 

                                                                                             

 

Author Response

Please see the attachment 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The paper is interesting and important for the medical society. For me, the most intersting are the limitations of the study, all of them are so serious, that made me assess the overall merit as "no answer". Additionally, I am wondering why the authors of the survey did not ask a question about vaccination. I am sure, a good share of the participants in the study, are not vaccinated. The authors of the survey know very well studies pointing to reduction in "brain fog" and other cognitive  impairements in immunized individuals compared to non-immunized ones. My opinion is the paper to be re-considered after addition of some factors controlling cognitive functions like vaccination and physical exercises.   

Author Response

Please see the attachment 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Thank you for addressing all comments.

Reviewer 2 Report

Comments and Suggestions for Authors

I read thouroughly the revised version and now the paper looks quite 
different! Now I believe it is much better, informative and brings a real input
into our knowledge about the Long Covid and cognitive limitations.
I recommend the aticle for publication in COVID!