Project Abstract/Summary Kidney transplantation is the preferred modality of treatment for end-stage kidney disease (ESKD) and is known to improve quality of life and survival of patients compared with dialysis. However, racial and ethnic disparities in access to kidney transplantation have persisted for more than two decades. The lower access of Black and Hispanic adults to kidney transplantation has been attributed to individual-level characteristics such as socioeconomic barriers, differences in cultural beliefs or attitudes surrounding organ transplantation, and higher prevalence of contraindications to kidney transplantation. However, system-level factors may contribute to the racial and ethnic inequities in access to kidney transplantation, but have not been thoroughly explored. In this renewal application, we propose to leverage electronic health record data to examine the role of providers and provider-patient interactions on inequities in access to referral for kidney transplant candidacy evaluation and waitlisting at University of California healthcare systems, Hennepin Healthcare, University of Minnesota, University of Maryland, and University of Texas Southwestern. We will focus on patients with CKD stage 4-5 who would potentially be eligible for referral for kidney transplantation in our study. In Aim 1, we will determine whether race/ethnicity associates with the language used in provider notes (positive or negative) and frequency of provider-patient interactions or monitoring. In Aim 2, we propose to evaluate whether these factors mediate the association between race/ethnicity and outcomes including preemptive referral for kidney transplant candidacy evaluation or transplant center decisions surrounding a patient’s eligibility for waitlisting. In Aim 3, we will then relate the language used in provider notes to outcomes following the onset of ESKD, such as first-year mortality and post-transplant outcomes (hospitalizations, rejection, and graft failure). We are particularly interested in the strength of these associations by race/ethnicity and whether effect modification is present. The results of our study will enhance our understanding of mediators of racial and ethnic disparities in access to transplantation and inform the design of interventions that can be delivered to address provider- related variables that may contribute to inequities in access to kidney transplantation.