Title: Association of FIB-4 Index and Clinical Outcomes in Critically ill Patients with Acute
Kidney Injury: A Cohort Study
Version: 1 Date: 23 Sep 2021
Reviewer's report:
This study aimed to investigate the association between the FIB-4 index and all-cause mortality
in critically ill patients with AKI. Logistic regression model and Cox proportional hazards model
were used to assess the relationship between the FIB-4 index and in-hospital, 28-day and 90-day
mortality, respectively. The authors concluded that the FIB-4 index is associated with clinical
outcomes in critically ill patients with acute kidney injury. The manuscript is well-written, and
the statistical analysis itself seems appropriate. However, I have a major concern as follow:
The FIB-4 index was calculated using the following equation: Fibrosis-4 index = (Age x AST) /
(Platelets x #ALT). Age is an important and well-known prognostic factor predicting death in
critically ill patients. According to the equation of the FIB-4 index, the age and FIB-4 index are
totally proportional. Thus, it could be undoubtedly expected that the FIB-4 index is associated
with mortality in critically ill patients with acute kidney injury, even in other critically ill patient
groups. Actually, the OR or HR calculated in this study is quite small (only about 1.1-1.2),
although the analyses were statistically significant, probably due to the large sample size. Even
the authors used quartile for analyses, the ORs for each quartile variable were only 1.2-1.7 (OR
of Q2 to Q4: 1.216–1.744, with Q1 as reference). Did the authors compare the performance of
the prediction models between the model, including age variable (+- AST, ALT, Platelet) vs. the
model included FIB-4 index? The authors should justify that the FIB-4 index has an additional
and clinically significant effect on predicting mortality compared with age itself. Otherwise, I
do not find any potential impact of the study results on clinical practice.
Title: Association of FIB-4 Index and Clinical Outcomes in Critically ill Patients with Acute
Kidney Injury: A Cohort Study
Version: 1 Date: 23 Sep 2021
Reviewer's report:
This study aimed to investigate the association between the FIB-4 index and all-cause mortality
in critically ill patients with AKI. Logistic regression model and Cox proportional hazards model
were used to assess the relationship between the FIB-4 index and in-hospital, 28-day and 90-day
mortality, respectively. The authors concluded that the FIB-4 index is associated with clinical
outcomes in critically ill patients with acute kidney injury. The manuscript is well-written, and
the statistical analysis itself seems appropriate. However, I have a major concern as follow:
The FIB-4 index was calculated using the following equation: Fibrosis-4 index = (Age x AST) /
(Platelets x #ALT). Age is an important and well-known prognostic factor predicting death in
critically ill patients. According to the equation of the FIB-4 index, the age and FIB-4 index are
totally proportional. Thus, it could be undoubtedly expected that the FIB-4 index is associated
with mortality in critically ill patients with acute kidney injury, even in other critically ill patient
groups. Actually, the OR or HR calculated in this study is quite small (only about 1.1-1.2),
although the analyses were statistically significant, probably due to the large sample size. Even
the authors used quartile for analyses, the ORs for each quartile variable were only 1.2-1.7 (OR
of Q2 to Q4: 1.216–1.744, with Q1 as reference). Did the authors compare the performance of
the prediction models between the model, including age variable (+- AST, ALT, Platelet) vs. the
model included FIB-4 index? The authors should justify that the FIB-4 index has an additional
and clinically significant effect on predicting mortality compared with age itself. Otherwise, I
do not find any potential impact of the study results on clinical practice.
Please review this paper.
user
Title: Association of FIB-4 Index and Clinical Outcomes in Critically ill Patients with Acute
Kidney Injury: A Cohort Study
Version: 1 Date: 23 Sep 2021
Reviewer's report:
This study aimed to investigate the association between the FIB-4 index and all-cause mortality
in critically ill patients with AKI. Logistic regression model and Cox proportional hazards model
were used to assess the relationship between the FIB-4 index and in-hospital, 28-day and 90-day
mortality, respectively. The authors concluded that the FIB-4 index is associated with clinical
outcomes in critically ill patients with acute kidney injury. The manuscript is well-written, and
the statistical analysis itself seems appropriate. However, I have a major concern as follow:
The FIB-4 index was calculated using the following equation: Fibrosis-4 index = (Age x AST) /
(Platelets x #ALT). Age is an important and well-known prognostic factor predicting death in
critically ill patients. According to the equation of the FIB-4 index, the age and FIB-4 index are
totally proportional. Thus, it could be undoubtedly expected that the FIB-4 index is associated
with mortality in critically ill patients with acute kidney injury, even in other critically ill patient
groups. Actually, the OR or HR calculated in this study is quite small (only about 1.1-1.2),
although the analyses were statistically significant, probably due to the large sample size. Even
the authors used quartile for analyses, the ORs for each quartile variable were only 1.2-1.7 (OR
of Q2 to Q4: 1.216–1.744, with Q1 as reference). Did the authors compare the performance of
the prediction models between the model, including age variable (+- AST, ALT, Platelet) vs. the
model included FIB-4 index? The authors should justify that the FIB-4 index has an additional
and clinically significant effect on predicting mortality compared with age itself. Otherwise, I
do not find any potential impact of the study results on clinical practice.
assistant