The Impact of Structural Racism on Racial/Ethnic Disparities in End-Stage Kidney Disease from Healthy Population to Mortality

Project Summary Racial disparities in the incidence and treatment of end-stage kidney disease are well-documented and largely consistent across outcomes, and an emerging consensus indicates that these disparities are likely to be primarily driven by structural racism (SR). Non-Hispanic Black, Hispanic persons of any race, and American Indian or Alaska Natives (AIAN) are a) at higher risk of chronic kidney disease (CKD) throughout their life course; b) more likely to progress from CKD to end-stage kidney disease (ESKD); c) less likely to be referred for kidney transplantation; d) less likely to obtain a living donor kidney transplant (LDKT); e) experience higher mortality hazards on the transplant waiting list and post-transplant; and f) experience higher rates of post- transplant graft failure. The major exception to this rule is the higher survival rate of Black and Hispanic ESKD patients on dialysis. For all other outcomes, the consistency with which highly similar disparities are observed across these disparate processes suggests that deeper mechanisms are at work — i.e., SR. To assess the hidden forces of SR underlying consistent disparities in ESKD, we will analyze a very large health survey linked to longitudinal Medicare claims, geospatial information, and mortality outcomes. Our approach to measuring SR will be multidimensional, capturing local racial/ethnic inequalities in economic, educational, judicial, political, and residential outcomes as well as health care affordability, contact, proximity, and quality. Furthermore, to fully reflect the contribution of divergent medical treatments to racial/ethnic disparities in ESKD patient outcomes, we will measure ESKD patients’ treatments over time, then identify the most important treatment trajectories for racial/ethnic disparities. In our Aim 1 analysis, we hypothesize that non-Hispanic Black, Hispanic, and AIAN individuals will have higher risk of ESKD development, and that SR will significantly explain these disparities. We will test this hypothesis by analyzing restricted Medicare claims and geospatial data linked to the National Health Interview Study (NHIS; 1994-present; N=941,492 Medicare-linkage-eligible respondents). In our Aim 2 analysis, we hypothesize that non-Hispanic Black, and AIAN respondents will be less likely to receive optimal treatment trajectories and more likely to receive suboptimal treatment trajectories than non-Hispanic Whites. We will construct treatment trajectories using sequence analysis techniques, and assess racial/ethnic disparities in treatment trajectories in the United States Renal Data System dataset (USRDS; 1997-2018; N=2,335,340). In our Aim 3 analyses, we investigate whether racial/ethnic ESKD patient survival advantages compared to non-Hispanic Whites are modified by SR and treatment trajectories. We hypothesize that SR and treatment trajectories both modify racial/ethnic disparities in ESKD patient outcomes, but that treatment trajectories will offer the greatest explanatory power due to their more proximate relationship to patient outcomes. We will test this hypothesis by assessing how well each characteristic statistically explains racial/ethnic disparities in ESKD patient mortality. Throughout the research process we will work with two established community advisory boards to generate novel ideas for analyses, results interpretation, and specific proposed interventions, and refine the proposed interventions for future testing with input from the board and ESKD health care professionals.