The Associations Between Individual-Versus Neighborhood-level Incomes and Kidney Transplant Outcomes

Background. Disparities in posttransplant outcomes persist and worsened during the COVID-19 pandemic, disproportionately affecting individuals with social risk factors. This study examined the total and residual (ie, direct) associations between individual- and neighborhood-level income and posttransplant outcomes among deceased donor kidney transplant (DDKT) and living donor kidney transplant recipients transplanted in the United States in 2020. Methods. This retrospective cohort study linked Organ Procurement and Transplantation Network data with estimated individual annual income from LexisNexis and neighborhood median annual household income from the American Community Survey. Multivariable Cox models assessed associations between income and 3-y all-cause graft survival, patient survival, and death-censored graft survival. Results. Among 14 091 DDKT recipients, lower individual income was associated with higher all-cause graft failure (adjusted hazard ratio aHR for lowest quartile Q1 versus highest Q4: 1.37; 95% confidence interval CI, 1.20-1.56) and death (aHR, 1.47; 95% CI, 1.26-1.72). Neighborhood income had weaker associations, though Q1 recipients still had higher all-cause graft failure (aHR, 1.17; 95% CI, 1.03-1.33) and death (aHR, 1.21; 95% CI, 1.04-1.41). In models including both income measures, only individual income remained significant. Censoring COVID-19 deaths attenuated associations for individual income, while neighborhood income was no longer significant. Among 4565 living donor kidney transplant recipients, income was not significantly associated with outcomes. Conclusions. Lower individual income predicts higher all-cause graft failure, primarily because of increased mortality in DDKT recipients. Neighborhood income has a weaker effect, particularly when censoring COVID-19 deaths. Targeted interventions are needed to improve equity in kidney transplantation, especially during public health crises.