Center Geography or Center Practice? Decomposing Geographic Variation in Access to Deceased Donor Liver...

Disparities in deceased donor liver transplantation (DDLT) may be due to geographic imbalances of organ supply-to-demand ratios and/or center organ acceptance practices. We evaluated the relative contribution of centers versus broader geographic units (DSAs/States/OPTN regions/census divisions) to variability of DDLT rate. Using SRTR data on adult, first-time, non-Status1A, period-prevalent waitlist candidates, we conducted multilevel Poisson regression with center-level and donor service area (DSA)-level intercepts to model DDLT rates across three eras: pre-acuity circles (AC)(5/1/2017-4/30/2019), initial post-AC (2/4/2020-2/3/2022), and recent post-AC (02/04/2022-12/31/2024), adjusting for candidate factors. We calculated center-level and DSA-level median incidence rate ratios (MIRRs) and their relative contributions to total geographic variation. DSA-level MIRR declined from _1.471.52_1.58 to _1.321.37_1.42 to _1.171.23_1.28 from pre-AC to initial post-AC to recent post-AC. The center-level, within-DSA MIRR increased from _1.561.61_1.64 to _1.761.82_1.84 to _1.921.96_2.05 across eras. The DSA-level contribution to total center-level variation declined from 43.7% to 21.5% to 8.4% across eras. Similarly, the contribution of other broad, geographic units (States/OPTN regions/census divisions) to total geographic variation in DDLT rates decreased after AC. Further allocation changes are unlikely to substantially reduce geographic disparities because DDLT rate variation is predominantly driven by center-level differences, which were associated with highly variable advanced preservation practices.