Association between the blood urea nitrogen-albumin ratio and mortality in critically ill patients with gastrointestinal bleeding: a retrospective cohort study

Abstract

Background: Acute gastrointestinal bleeding (GIB) represents a life-threatening medical emergency. This study investigates the prognostic utility of the Blood Urea Nitrogen-to-albumin ratio (BAR) in patients with GIB. Methods: Patients were stratified according to BAR levels. The association between BAR and 28-day and 1-year mortality was examined using Cox proportional hazards regression, restricted cubic splines (RCS), and Kaplan-Meier (KM) analysis. Comprehensive subgroup analyses were further conducted to evaluate consistency across clinically relevant strata. Results: In this study, a total of 1624 patients were included. Elevated BAR was an independent predictor of higher mortality at 28 days (HR 1.03, 95% CI 1.02–1.04) and 1 year (HR 1.02, 95% CI 1.01–1.03; both P < 0.001). Receiver Operating Characteristic (ROC) analysis indicated moderate discrimination for mortality prediction. Restricted cubic splines suggested a linear dose-response relationship between BAR and mortality. Significant interactions were observed with acute kidney injury (AKI) and continuous renal replacement therapy (CRRT). A nomogram incorporating BAR and other predictors achieved AUCs of 0.805 (0.779–0.832) for 28-day and 0.789 (0.765–0.814) for 1-year mortality. Conclusion: This study demonstrates that an elevated BAR independently predicts mortality in patients with GIB.