ALBI Grade Is Associated with Clinical Outcomes of Critically Ill Patients with AKI: A Cohort Study with Cox Regression and Propensity Score Matching

Background . The albumin–bilirubin (ALBI) grade has surfaced as a viable substitute for assessing liver functional reserve in individuals afflicted with hepatocellular carcinoma (HCC). ALBI grade also demonstrates the capacity to stratify distinct patient subcohorts bearing disparate prognostic implications in not only HCC but also other inflammatory diseases like acute pancreatitis. However, the association between ALBI grade and clinical outcomes of acute kidney injury (AKI) remains mysterious. Methods . The dataset was sourced from the Multiparameter Intelligent Monitoring in Intensive Care Database IV (MIMIC‐IV) version 2.0. ALBI grade was calculated in a nomogram utilizing albumin and bilirubin. In order to ascertain the connection between ALBI grades and clinical outcomes of patients with AKI, Cox proportional hazards regression analysis was employed with in‐hospital, 30‐ and 90‐day mortality as end points, respectively. The Kaplan–Meier (K–M) curve was employed to gauge the cumulative incidence of mortality based on various ALBI grades. To explore potential nonlinear relationships, the Restricted Cubic Spline (RCS) approach was adopted. Furthermore, a subgroup analysis was conducted to validate the durability of the correlation between ALBI grade and in‐hospital mortality. Furthermore, equilibrium of confounding variables was also achieved through the application of propensity score matching (PSM). Results . The study encompassed a total of 12,518 patients (ALBI grade 1 : 2878, grade 2 : 6708, and grade 3 : 2932). Patients with heightened ALBI grades displayed a significant correlation with increased mortality in both univariate and various multivariate Cox regression models. RCS depicted a predominantly linear relationship. The robustness of the correlation was also affirmed across multifarious subpopulations through subgroup analysis. The association still remains after PSM. Conclusion . Elevated ALBI grade was associated with worse clinical outcomes of critically ill patients with AKI.