Association between red cell distribution width-to-albumin ratio and all-cause mortality in critically ill cirrhotic patients with sepsis: a retrospective analysis of the MIMIC-IV database.

Background: Critically ill cirrhotic patients are at high risk of infections, which are associated with significantly increased mortality. The red cell distribution width-to-albumin ratio (RAR) is a validated predictor of mortality in critically ill patients. However, the prognostic value of RAR in critically ill cirrhotic patients with sepsis has not been fully established. Methods: This study retrospectively analyzed data from the Medical Information Mart for Intensive Care (MIMIC-IV) database. Patients were stratified into quartiles based on RAR values. The primary outcomes were 30-day and 365-day all-cause mortality. Kaplan-Meier survival analysis and multivariable Cox regression models were applied to assess the association between RAR and mortality. Restricted cubic spline (RCS) analysis confirmed a linear relationship and subgroup analyses explored potential interactions. Results: A total of 2,100 patients were included. Elevated RAR values were significantly associated with increased 30-day and 365-day all-cause mortality. Compared with the lowest quartile, patients in the highest RAR quartile had a 51% higher risk of 30-day mortality [hazard ratio (HR) = 1.51, 95% confidence interval (CI): 1.19-1.92) and a 51% higher risk of 365-day mortality (HR = 1.51, 95% CI: 1.25-1.81). RCS analysis confirmed a significant linear relationship between RAR and mortality risk. Subgroup analyses showed a stronger association between RAR and mortality in elderly patients. Conclusion: In critically ill cirrhotic patients with sepsis, elevated RAR values are independently associated with increased all-cause mortality risk. This study highlights the potential of RAR as a prognostic biomarker, particularly in elderly patients.