Association Between Kidney Dysfunction Types and Mortality Among Hospitalized Patients with Cirrhosis.

ABSTRACT

BACKGROUND AND AIMS: Kidney dysfunction is associated with increased mortality among patients with cirrhosis. We investigated whether kidney dysfunction types [e.g., acute kidney injury (AKI), chronic kidney disease (CKD), and AKI on CKD] were differentially associated with inpatient mortality. METHODS: We utilized the nationwide inpatient sample, a nationally representative database, from 2007 to 2014. We included all hospitalizations with previously validated codes for cirrhosis or associated decompensated cirrhosis diagnoses. We defined kidney dysfunction types also from previously validated codes, and we grouped hospitalizations into the following diagnoses normal, AKI, CKD, and AKI on CKD. Our primary outcome was inpatient mortality. RESULTS: There were 1,293,779 hospitalizations with cirrhosis sampled in this study. Of these hospitalizations, 849,193 (66%) had normal kidney function, 176,418 (14%) had AKI, 157,600 (12%) had CKD, and 110,568 (9%) had AKI on CKD. We found that the proportion of hospitalizations with AKI, CKD, and AKI on CKD increased significantly throughout the study period (p < 0.001, test for trend for all). Kidney dysfunction type was differentially associated with inpatient mortality, even after adjustment as compared to those with CKD, normal kidney function OR 0.75 [95 CI 0.73-0.78], AKI OR 2.40 [95 CI 2.32-2.48], and AKI on CKD OR 1.66 [95 CI 1.60-1.72]. DISCUSSION: Using a nationally representative cohort of all hospitalizations with cirrhosis, our study highlights that the burden of kidney dysfunction, especially AKI, among hospitalizations with cirrhosis is rising, and the inclusion of kidney dysfunction type may be an opportunity to improve prognostication.