Associations between socioeconomic factors and post-liver transplant mortality across recovery phases

Socioeconomic status (SES) is a well-established determinant of liver transplantation (LT) outcomes, but prior studies have treated SES as a static baseline attribute, assessed only at fixed milestones such as 1- or 5-year mortality. Although the existing body of work has established the importance of SES in post-transplant care, this approach overlooks the dynamic and time-sensitive nature of socioeconomic risk across the recovery trajectory, potentially missing critical details that could inform timely and targeted interventions. Using the United Network for Organ Sharing registry, we analyzed 105,907 adult recipients of LT from 2005 to 2022. Follow-up was divided into 4 intervals defined using sliding-window and time-varying Cox analyses to detect the earliest onset of ZIP code-level median household income and Social Deprivation Index (SDI) effects on survival. Interval-specific clinical, surgical, and demographic covariates were selected using least absolute shrinkage and selection operator regression, and income and SDI quartiles were incorporated separately into multivariable Cox models with time-varying covariates to assess independent associations with mortality. During the immediate and early postdischarge periods, neither income nor SDI was independently associated with mortality. Beginning at 4-12 months, higher SDI was significantly associated with increased mortality (HR: 1.12, 95% CI: 1.02-1.23), with the effects intensifying over time (time-varying HR: 1.38, 95% CI: 1.10-1.73). Income-related disparities emerged later, becoming significant during long-term follow-up beyond 1 year, when lower income quartiles were independently associated with excess mortality (lowest quartile: HR: 1.17, 95% CI: 1.11-1.24). These findings demonstrate that socioeconomic vulnerability after LT is not fixed but evolves over time. This study introduces a time-resolved framework that identifies when SES factors first become consequential, highlighting actionable windows for targeted interventions to reduce inequities in post-transplant care.