Evaluation of Community-Level Vulnerability and Racial Disparities in Living Donor Kidney Transplant.

Importance: Living donor kidney transplant (LDKT) is the ideal treatment for end-stage kidney disease, but racial disparities in LDKT have increased over the last 2 decades. Recipient clinical and social factors do not account for LDKT racial inequities, although comprehensive measures of community-level vulnerability have not been assessed. Objective: To determine if racial disparities persist in LDKT independent of community-level vulnerability. Design, Setting, and Participants: This retrospective, multicenter, cross-sectional study included data from 19 287 adult kidney-only transplant recipients in the Scientific Registry of Transplant Recipients. The study included individuals who underwent transplant between January 1 and December 31, 2018. Exposures: Recipient race and the 2018 US Centers for Disease Control and Prevention Social Vulnerability Index (SVI). Census tract-level SVI data were linked to census tracts within each recipient zip code. The median SVI measure among the census tracts within a zip code was used to describe community-level vulnerability. Main Outcomes and Measures: Kidney transplant donor type (deceased vs living). Modified Poisson regression was used to evaluate the association between SVI and LDKT, and to estimate LDKT likelihood among races, independent of community-level vulnerability and recipient-level characteristics. Results: Among 19 287 kidney transplant recipients, 6080 (32%) received LDKT. A total of 11 582 (60%) were male, and the median (interquartile range) age was 54 (43-63) years. There were 760 Black LDKT recipients (13%), 4865 White LDKT recipients (80%), and 455 LDKT recipients of other races (7%; American Indian, Asian, multiracial, and Pacific Islander). Recipients who lived in communities with higher SVI (ie, more vulnerable) had lower likelihood of LDKT compared with recipients who lived in communities with lower SVI (ie, less vulnerable) (adjusted relative risk [aRR], 0.97; 95% CI, 0.96-0.98; P < .001). Independent of community-level vulnerability, compared with White recipients, Black recipients had 37% lower likelihood (aRR, 0.63; 95% CI, 0.59-0.67; P < .001) and recipients of other races had 24% lower likelihood (aRR, 0.76; 95% CI, 0.70-0.82; P < .001) of LDKT. The interaction between SVI and race was significant among Black recipients, such that the disparity in LDKT between Black and White recipients increased with greater community-level vulnerability (ratio of aRRs, 0.67; 95% CI, 0.51-0.87; P = .003). Conclusions and Relevance: Community-level vulnerability is associated with access to LDKT but only partially explains LDKT racial disparities. The adverse effects of living in more vulnerable communities were worse for Black recipients. The interaction of these constructs is worrisome and suggests evaluation of other health system factors that may contribute to LDKT racial disparities is needed.