Abstract
To explore whether red blood cell distribution width-albumin ratio (RAR) is relevant to in-hospital mortality among abdominal aortic aneurysm (AAA). This is a retrospective study retrieving data from the MIMIC-IV database. Patients were divided into survivor or non-survivor groups by the in-hospital mortality. Receiver operating characteristic curve analysis, logistic regression models, subgroup analysis, interaction analysis, and restricted cubic spline analysis were conducted to analyze the correlation between RAR and in-hospital mortality. Then, we divided patients into 2 groups by an optimal cutoff value of RAR to identify the factors independently linked to RAR. Following this, the mediation analysis was conducted to reveal the potential regulatory path. Finally, we assessed the clinical value of RAR in secondary outcomes containing length of hospital stay, intensive care unit (ICU) admission, and ICU stay. Totally 770 participants with AAA were enrolled: 722 survivors and 48 non-survivors. Higher RAR was observed in the non-survivor group and its level performed satisfactorily in predicting in-hospital mortality. AAA patients were more likely to die during in-hospital with the increase of RAR (P < .05) and this linear correlation was revealed by restricted cubic spline (P non-linear > .05). Additionally, urea nitrogen and creatinine were independently related to RAR. RAR served as a mediator in the association of urea nitrogen/creatinine with in-hospital mortality. Finally, the length of hospital stay and ICU stay were longer in the RAR ≥ 4.658 group (P < .05). RAR is a potential risk predictor for in-hospital mortality in AAA patients. Further, RAR upregulation was significantly correlated with prolonged length of hospital stay and ICU stay.