Introduction:
To explore the association of red blood cell distribution width-to-albumin ratio (RAR) with 28-day mortality among septic patients, as well as to develop predictive models for evaluating the prognostic significance of RAR.

Material and methods:
Relevant information was obtained from the Medical Information Mart for Intensive Care (MIMIC-III). A total of 1475 individuals diagnosed with sepsis were enrolled. Data on patients’ age, creatinine levels, and mechanical ventilation status in the initial 24 h after intensive care unit (ICU) admission were gathered. We employed multivariate COX analyses to investigate the correlation between RAR and 28-day mortality, and we conducted subgroup analyses stratified by gender, age, intervention modality, and disease progression. We established 4 prediction models relevant to RAR to forecast the 28-day mortality of septic patients. Additionally, we evaluated the predictive value using receiver operator characteristic curves.

Results:
The significance of the association between RAR and 28-day mortality was maintained among sepsis patients regardless of their use or non-use of mechanical ventilation or vasopressor, presence or absence of septic shock, and gender (male or female). Additionally, these developed models associated with RAR demonstrated a good predictive value in forecasting the 28-day mortality rate among septic patients.

Conclusions:
This study provides evidence, suggesting a significant correlation between RAR and the 28-day mortality among sepsis patients of ICU admission. It might show promise of RAR as a potential dependable prognostic marker for the prediction of 28-day mortality in sepsis patients.