Use of population-based data to demonstrate how waitlist-based metrics overestimate geographic disparities in access to liver transplant care

Abstract

Liver allocation policies are evaluated by how they impact waitlisted patients, without considering broader outcomes for all patients with end-stage liver disease (ESLD) not on the waitlist. We conducted a retrospective cohort study using two nationally representative databases: HealthCore (2006–2014) and five-state Medicaid (California, Florida, New York, Ohio and Pennsylvania; 2002–2009). United Network for Organ Sharing (UNOS) linkages enabled ascertainment of waitlist- and transplant-related outcomes. We included patients aged 18–75 with ESLD (decompensated cirrhosis or hepatocellular carcinoma) using validated International Classification of Diseases, Ninth Revision (ICD-9)–based algorithms. Among 16 824 ESLD HealthCore patients, 3-year incidences of waitlisting and transplantation were 15.8% (95% confidence interval [CI] : 15.0– 16.6%) and 8.1% (7.5–8.8%), respectively. Among 67 706 ESLD Medicaid patients, 3-year incidences of waitlisting and transplantation were 10.0% (9.7– 10.4%) and 6.7% (6.5–7.0%), respectively. In Health-Core, the absolute ranges in states’ waitlist mortality and transplant rates were larger than corresponding ranges among all ESLD patients (waitlist mortality: 13.6–38.5%, ESLD 3-year mortality: 48.9–62.0%; waitlist transplant rates: 36.3–72.7%, ESLD transplant rates: 4.8–13.4%). States’ waitlist mortality and ESLD population mortality were not positively correlated: ρ = -0.06, p-value = 0.83 (HealthCore); ρ = -0.87, p-value = 0.05 (Medicaid). Waitlist and ESLD transplant rates were weakly positively correlated in Medicaid (ρ = 0.36, p-value = 0.55) but were positively correlated in HealthCore (ρ = 0.73, p-value = 0.001). Compared to population-based metrics, waitlist-based metrics overestimate geographic disparities in access to liver transplantation.