Neighborhood Segregation and Access to Live Donor Kidney Transplantation

Abstract

ImportanceIdentifying the mechanisms of structural racism, such as racial and ethnic segregation, is a crucial first step in addressing the persistent disparities in access to live donor kidney transplantation (LDKT).ObjectiveTo assess whether segregation at the candidate’s residential neighborhood and transplant center neighborhood is associated with access to LDKT.Design, Setting, and ParticipantsIn this cohort study spanning January 1995 to December 2021, participants included non-Hispanic Black or White adult candidates for first-time LDKT reported in the US national transplant registry. The median (IQR) follow-up time for each participant was 1.9 (0.6-3.0) years.Main Outcome and MeasuresSegregation, measured using the Theil H method to calculate segregation tertiles in zip code tabulation areas based on the American Community Survey 5-year estimates, reflects the heterogeneity in neighborhood racial and ethnic composition. To quantify the likelihood of LDKT by neighborhood segregation, cause-specific hazard models were adjusted for individual-level and neighborhood-level factors and included an interaction between segregation tertiles and race.ResultsAmong 162 587 candidates for kidney transplant, the mean (SD) age was 51.6 (13.2) years, 65 141 (40.1%) were female, 80 023 (49.2%) were Black, and 82 564 (50.8%) were White. Among Black candidates, living in a high-segregation neighborhood was associated with 10% (adjusted hazard ratio [AHR], 0.90 [95% CI, 0.84-0.97]) lower access to LDKT relative to residence in low-segregation neighborhoods; no such association was observed among White candidates (P for interaction = .01). Both Black candidates (AHR, 0.94 [95% CI, 0.89-1.00]) and White candidates (AHR, 0.92 [95% CI, 0.88-0.97]) listed at transplant centers in high-segregation neighborhoods had lower access to LDKT relative to their counterparts listed at centers in low-segregation neighborhoods (P for interaction = .64). Within high-segregation transplant center neighborhoods, candidates listed at predominantly minority neighborhoods had 17% lower access to LDKT relative to candidates listed at predominantly White neighborhoods (AHR, 0.83 [95% CI, 0.75-0.92]). Black candidates residing in or listed at transplant centers in predominantly minority neighborhoods had significantly lower likelihood of LDKT relative to White candidates residing in or listed at transplant centers located in predominantly White neighborhoods (65% and 64%, respectively).ConclusionsSegregated residential and transplant center neighborhoods likely serve as a mechanism of structural racism, contributing to persistent racial disparities in access to LDKT. To promote equitable access, studies should assess targeted interventions (eg, community outreach clinics) to improve support for potential candidates and donors and ultimately mitigate the effects of segregation.

Neighborhood Racial and Ethnic Segregation and the Risk of Dementia in Older Adults Living with Kidney Failure

“…We assigned segregation scores for older adults with kidney failure based on the residential neighborhoods identified by their five-digit ZIP code at the time of dialysis initiation, which we used as proxies for neighborhoods. Consistent with previous research, 11,[26][27][28][29][30][31] segregation scores were categorized into tertiles: low (,7.2), medium ($7.2 and ,13.0), and high (.13.0) segregation.…”

“…Segregation, rooted in historical injustices such as discriminatory zoning and redlining, 57 perpetuates unequal resource distribution and concentrated areas with poor social conditions. 25,26,57 Coupled with greater exposure to air pollution, crime, 7,58,59 and reduced social capital, these factors significantly affect the health and cognitive function of older adults with kidney failure, 14 especially within Black communities. 8 Furthermore, we found that older adults with kidney failure who relocated to neighborhoods with different segregation levels did not exhibit a significant change in their risk of dementia diagnosis compared with those who did not relocate.…”

“…While this may be prone to spatial misclassification and modifiable areal unit problems, 85 ZIP codes are commonly used ecological units to define neighborhoods. 26,86,87 Second, we defined segregation based on aggregated counts of racial and ethnic groups within ZCTAs, which may not fully capture the multifaceted dimensions of structural racism within neighborhoods. Nevertheless, our findings remained consistent across different definitions or measures of segregation.…”

“…We used Iceland's Multigroup Entropy (Thiel's H) Index to quantify segregation across multiple racial and ethnic groups simultaneously. [22][23][24][25][26] This involved analyzing diversity within ZCTAs and the distribution of populations within counties. To ensure a comprehensive representation of racial and ethnic diversity, our calculations included the following categories: non-Hispanic Asian, non-Hispanic Black, Hispanic, non-Hispanic Other, and non-Hispanic White (see the Supplemental Material: Calculations).…”

“…Potential predictors for dementia diagnosis were ascertained from the CMS-2728 form. 26,[32][33][34][35] In addition, we considered the following neighborhood-level factors obtained from the American Community Survey 5-year estimates selected based on the literature 2,[33][34][35][36][37] : percentage of residents with $high school degree and $bachelor's degree, and median household income.…”