Review for 10.1186/s12876-025-03887-y (2025)

Title: Independent effects of the hemoglobin-to-red blood cell distribution width ratio on 180-
day mortality in critically ill patients with gastrointestinal bleeding: analysis from the MIMIC-
IV database
Version: 5 Date: 31 Mar 2025
Reviewer's report:
Thank you once again for the opportunity to review your work. I would like to provide
some additional comments on your response. I hope these comments will contribute to the
improvement of your manuscript.
Regarding 180-day mortality, it is acceptable to evaluate survival rate using HR. The issue lies
in stating "180-day mortality" and having an evaluation method fixed to this specific timeframe.
As I mentioned repeatedly, 180-day mortality means the mortality rate at 180 days. The authors
stated at the beginning that the association between HRR and 180-day mortality is unclear. Then,
is the association known for 120 days? There is no need to fix it to 180 days here; it would
be sufficient to simply state that the association between HRR and prognosis is unclear. The
expression "180-day mortality" focuses on the mortality rate at 180 days rather than HR, giving
a strong impression that the primary outcome is the survival rate at 180 days, not HR. To avoid
such misunderstandings, it would be better to omit "180-day mortality." It is common to set the
primary outcome as the survival rate during the observation period. If that is not the case, please
clearly state the rationale for using 180 days somewhere in the paper."
If the cause of death is other than GIB, it will significantly affect the analysis results. While I
understand the data limitations, it is important to discuss this cautiously in the discussion section,
rather than simply mentioning it in the limitations.
Again, it is not common to perform subgroup analysis using quartile ranges or median values.
While some journals might accept this, I reiterate that it is not scientifically sound. First, it is
unclear whether the values divided by these quartile ranges are generally considered high or
low. Furthermore, the validity of the values divided by quartile ranges is highly questionable.
This idea appears unnatural when considering external validation. The authors mention the
association with depression and frailty in the discussion. Considering these reports, what are the
approximate values of the obtained cut-off values?
Regarding patient characteristic 2 (Table 2), as I have mentioned repeatedly, the purpose of this
study is to identify prognostic factors of GIB based on patient characteristics at the time of ICU
admission. Therefore, while patient background information at ICU admission is important, this
table is not that crucial. Also, was there no censoring in the data used this time? If censored
cases were treated as non-survivors, it would be a significant error, so please correct it.
Regarding the discussion for depression and frailty: The discussion section is a dialogue with
other research. It is not simply a place to report similar previous findings. In the next section,
you describe why GIB is associated with prognosis. Similarly, a comprehensive discussion is
needed on why depression and frailty, like GIB, have an impact on the human body.