Prognostic value of the red blood cell distribution width/albumin ratio in patients with diabetes mellitus combined with sepsis: a retrospective cohort study based on MIMIC-IV

OBJECTIVE: This study investigated the relationship between red cell distribution width (RDW)/albumin ratio (RAR) and 30-day and 360-day mortality in patients with diabetes mellitus combined with sepsis. METHODS: We selected patients with diabetes mellitus comorbid with sepsis from the Intensive Care Medical Information Marketplace MIMIC-IV (3.0) database and classified these patients by median RAR. The outcome measures were 30-day and 360-day mortality. General baseline patient information was described; Kaplan-Meier survival curves were plotted to determine the difference in mortality between the two RAR groups. The accuracy of RAR in predicting 30-day and 360-day mortality in patients with diabetes mellitus and sepsis was assessed by calculating receiver operating characteristic curves (ROC) and the area under the curve (AUC). The relationship between RAR and 30- and 360-day all-cause mortality in patients with diabetes mellitus with sepsis was assessed using Cox regression models and subgroup analyses. Cox proportional hazards models and subgroup survival analyses were used to determine the association between RAR and 30- and 360-day mortality in patients with diabetes mellitus with sepsis. RESULTS: A total of 2168 eligible patients with diabetes mellitus combined with sepsis between 2008 and 2022 were included in the study, with 30-day and 360-day mortality rates of 34.1% and 50.6%, respectively; the ROC curves comparing patients' 30- and 360-day mortality rates showed an area under the curve (AUC) of 0.643 (360-day mortality outcome) for RAR and 0.612 for SOFA; the area under the curve was higher for RAR than for SOFA scores (P<0.05); when RAR was combined with SOFA, the outcome was still higher than when SOFA was used alone; in the Cox proportional hazards model, after adjustment for confounders, RAR was an independent risk factor for patients with diabetes combined with sepsis (HR=1.085,95% CI:1.049-1.122, P<0.001), and patients in the high RAR level group had a 34.3% increased risk of 30-day mortality (HR=1.343,95% CI:1.138-1.586; P <0.001). The 360-day risk of death was increased by 42.3% (HR=1.423,95% CI: 1.243-1.629; P <0.001). All results were consistent in subsequent subgroups. CONCLUSIONS: High RAR is an independent risk factor for 30- and 360-day all-cause mortality in adults with diabetes mellitus combined with sepsis. RAR can be used as a prognostic indicator for this condition.