Title: Risk of Severe COVID-19 and Mortality in Patients with Established Chronic Liver
Disease: A Nationwide Matched Cohort Study
Version: 3 Date: 07 Jun 2021
Reviewer's report:
I congratulate the authors for their study. I made a few suggestionf to potentially improve the
reporting of their results:
1. How did you select controls? You named them "without recorded CLD" - but based on clinical
or histopathology data? How did you select 5 of them per each case - randomly or by any other
method? This aspect is of paramount relevance and this influences decisively or HR estimates.
2. The cases had higher prevalence of all comorbidities measured at index date (biopsy), many
of them the main risk factors for severe COVID in the general population and some of them
intrinsically related to CLD (e.g. metabolic syndrome); how can we say that this did not have
at least a similar impact on CLD patients and per se increased the risk of COVID complications
further? Don't you think the prevalence of COVID in your sample is just too small (follw-up
from 02 to 07/2020)?
3. Cases showed higher all-cause mortality rate but similar severe COVID rate. Could this
mortality excess be attributable to liver disease only or just no-covid-related factors? Could the
impact of the COVID pandemic on the health system be the driver of this mortality excess or
this difference would be similar in preCOVID era? Are there any other explanations?
4. I would suggest the authors elaborate more on the impact of their findings namely: (1) a
plausible biological explanation for the apparent lack of increased risk of severe COVID among
CLD patients; (2) the lessons for the every-day clinician and for public health authorities for
this and perhaps another viral pandemic.
5. I praise the authors for the space dedicated to the limitations of their study, I fully agree with
them.
Title: Risk of Severe COVID-19 and Mortality in Patients with Established Chronic Liver
Disease: A Nationwide Matched Cohort Study
Version: 3 Date: 07 Jun 2021
Reviewer's report:
I congratulate the authors for their study. I made a few suggestionf to potentially improve the
reporting of their results:
1. How did you select controls? You named them "without recorded CLD" - but based on clinical
or histopathology data? How did you select 5 of them per each case - randomly or by any other
method? This aspect is of paramount relevance and this influences decisively or HR estimates.
2. The cases had higher prevalence of all comorbidities measured at index date (biopsy), many
of them the main risk factors for severe COVID in the general population and some of them
intrinsically related to CLD (e.g. metabolic syndrome); how can we say that this did not have
at least a similar impact on CLD patients and per se increased the risk of COVID complications
further? Don't you think the prevalence of COVID in your sample is just too small (follw-up
from 02 to 07/2020)?
3. Cases showed higher all-cause mortality rate but similar severe COVID rate. Could this
mortality excess be attributable to liver disease only or just no-covid-related factors? Could the
impact of the COVID pandemic on the health system be the driver of this mortality excess or
this difference would be similar in preCOVID era? Are there any other explanations?
4. I would suggest the authors elaborate more on the impact of their findings namely: (1) a
plausible biological explanation for the apparent lack of increased risk of severe COVID among
CLD patients; (2) the lessons for the every-day clinician and for public health authorities for
this and perhaps another viral pandemic.
5. I praise the authors for the space dedicated to the limitations of their study, I fully agree with
them.
Please review this paper.
user
Title: Risk of Severe COVID-19 and Mortality in Patients with Established Chronic Liver
Disease: A Nationwide Matched Cohort Study
Version: 3 Date: 07 Jun 2021
Reviewer's report:
I congratulate the authors for their study. I made a few suggestionf to potentially improve the
reporting of their results:
1. How did you select controls? You named them "without recorded CLD" - but based on clinical
or histopathology data? How did you select 5 of them per each case - randomly or by any other
method? This aspect is of paramount relevance and this influences decisively or HR estimates.
2. The cases had higher prevalence of all comorbidities measured at index date (biopsy), many
of them the main risk factors for severe COVID in the general population and some of them
intrinsically related to CLD (e.g. metabolic syndrome); how can we say that this did not have
at least a similar impact on CLD patients and per se increased the risk of COVID complications
further? Don't you think the prevalence of COVID in your sample is just too small (follw-up
from 02 to 07/2020)?
3. Cases showed higher all-cause mortality rate but similar severe COVID rate. Could this
mortality excess be attributable to liver disease only or just no-covid-related factors? Could the
impact of the COVID pandemic on the health system be the driver of this mortality excess or
this difference would be similar in preCOVID era? Are there any other explanations?
4. I would suggest the authors elaborate more on the impact of their findings namely: (1) a
plausible biological explanation for the apparent lack of increased risk of severe COVID among
CLD patients; (2) the lessons for the every-day clinician and for public health authorities for
this and perhaps another viral pandemic.
5. I praise the authors for the space dedicated to the limitations of their study, I fully agree with
them.
assistant