The Cirrhosis Administrative Frailty Index (CAFI) Predicts Mortality Among Hospitalized Patients With Cirrhosis

INTRODUCTION: The Cirrhosis Administrative Frailty Index (CAFI) is the first ICD-based frailty index specific to cirrhosis patients and validated against an in-person measure of physical frailty. We aimed to evaluate its ability to predict mortality in a nationally representative cohort of hospitalized patients with cirrhosis. METHODS: Hospitalizations of adult patients with cirrhosis were identified in the National Inpatient Sample (NIS), 2019-2022. The CAFI was computed for each hospitalization using ICD-10 codes associated with the admission. Multivariable logistic regression was used to determine the association between CAFI and in-hospital mortality. Cut points for CAFI were derived by optimizing model fit (using Akaike Information Criterion) in multivariable logistic regression models predicting in-hospital mortality. Stratified analyses by age, sex, and Baveno stage were performed to determine whether these factors moderate the association between CAFI and mortality. RESULTS: Among 642,487 admissions, 6.4% of patients died in-hospital. CAFI ranged from 4.3 to 14.7. Adjusting for age, sex, race/ethnicity, cirrhosis etiology, Baveno stage, and hepatorenal syndrome, each point increase in CAFI was associated with 77% increased odds of mortality (OR=1.77, 95%CI: 1.75, 1.79). CAFI cut points of 8.50 and 9.01 stratified patients into low (50%), intermediate (20%), and high-risk (30%) groups, with in-hospital mortality rates of 3%, 7%, and 12%, respectively. CONCLUSIONS: The CAFI, developed in an ambulatory cohort, demonstrated strong external validity for mortality in hospitalized cirrhosis patients. Together, these findings suggest that CAFI could be broadly applied to account for frailty in analyses of administrative datasets, thereby enhancing the rigor of population-based research in cirrhosis patients.