Abstract
BACKGROUND: Sepsis-associated delirium (SAD) is a common and severe acute neuropsychiatric manifestation in patients with sepsis, which is associated with increased mortality and lasting cognitive deficits. The red cell distribution width to albumin ratio (RAR) has been recognized as a robust prognostic indicator for adverse outcomes across various diseases. This study aims to investigate the relationship between RAR and short-term mortality in patients with SAD after admission to the intensive care unit (ICU). METHODS: This retrospective cohort study leveraged the MIMIC-IV 3.1 database to analyze the primary outcome of all-cause mortality within 30 days of ICU admission for patients with SAD. According to the receiver operating characteristic(ROC) curve to determine the optimal cut-off point of RAR, SAD patients were divided into low RAR group (RAR < 5.85) and high RAR group (RAR ≧ 5.85). To mitigate potential confounding factors, a 1:1 propensity score matching (PSM) method was implemented. The relationship between RAR and short-term mortality was further assessed using multivariate Cox proportional hazards regression models and Kaplan-Meier (KM) survival curve analyses. RESULTS: The study included 4021 patients with SAD. After PSM, 1063 score-matched pairs of patients were generated. Cox proportional hazards models were adjusted for potential confounders, Patients with elevated RAR (≥ 5.85) exhibited a significantly higher 30-day mortality rate compared to those with a lower RAR (< 5.85), with a hazard ratio (HR) of 1.53 (95% CI: 1.35-1.75, P < 0.001). Propensity scores matching analysis corroborated these results, consistently indicating a higher mortality rate in the high RAR group, with an HR of 1.39 (95% CI: 1.19-1.61, P < 0.001). CONCLUSIONS: An Elevated RAR upon ICU admission was independently associated with an increased risk of short-term mortality in patients with SAD.