Abstract
Background: We aimed to investigate the relationship between the blood urea nitrogen (BUN) to serum albumin ratio (BAR) in critically ill patients with aspiration pneumonia (AP).
Methods: This is a retrospective cohort study from the Medical Information Mart for Intensive Care III (MIMIC-III) database, in which patients in ICU were diagnosed with aspiration pneumonia.The receiver operating characteristic (ROC) curve and survival curves were plotted to evaluate predictive performance of BAR.The multivariable Cox regression analysis were used to investigate the relationship between BAR and mortality. And subgroup analyses were stratified by relevant covariates.
Results: A total of 1121 critically ill patients with AP were enrolled in our study.
Patients in 28-day non-survivor group had significantly higher levels of BAR (P<0.001). The area under the curve (AUC) for predicting 28-day mortality, 90-day and 365-day mortality of BAR (0.693, P<0.001; 0.701, P<0.001; 0.703, P<0.001) was superior to that of SOFA scores or CURB-65 scores. Kaplan-Meier curves also showed similar results (P < 0.001). Multivariate cox regression analysis showed that BAR was a significant risk factor predicting 28-day (HR 1.89, 95%CI 1.37-2.60, P<0.001), 90-day (HR 1.76, 95%CI 1.34-2.31, P<0.001) and 365-day (HR 1.50, 95%CI 1.18-1.89, P=0.001) mortality even after adjusting for confounding variables such as age, gender, ethnicity, risk factors, comorbidities, interventions, score system, vital signs and laboratory results. This also showed intuitively in the restricted cubic spline curve. Moreover, subgroup analyses demonstrated a significant association between elevated BAR and 28-day mortality in mostly relevant subclasses.
Conclusions: Easily accessible BAR is a good prognostic predictor for critically ill patients with AP.