Background: Social determinants of health (SDOH) may be associated with disparities in access to solid organ transplant. However, national registries including the Organ Procurement and Transplantation Network (OPTN) do not, and may be unable to, collect comprehensive data on patient-level SDOH. To address concerns about the resource burden of collecting additional patient-level SDOH variables, the OPTN examined the use of existing commercial data sources.

Objective: Summarize literature reporting the use of commercial data sources to characterize SDOH and identify gaps in current knowledge, and potential applications of SDOH data in the development and evaluation of organ allocation policies in the United States.

Methods: We conducted a review of literature reporting use of patient-level SDOH derived from commercial data sources. We reviewed organ allocation policy proposals and monitoring reports published by the OPTN.

Results: We found a growing body of literature utilizing patient address and patient-level SDOH from commercial data sources. Commercially derived patient-level SDOH were reported to improve machine learning model predictions aimed at identifying high-risk patients. Prior work by our group found that patient-level SDOH were associated with kidney transplant waitlist outcomes. Main findings from epidemiologic studies validated the use of patient address obtained from commercial data sources.

Conclusion: Linking national registry data to commercial data sources provides new opportunities to monitor the relationship between SDOH and health outcomes. Future work should consider the use of commercial databases to monitor SDOH among solid organ candidates, recipients and living donors before and after changes in national organ allocation policies.

Background: Living donor kidney transplant (LDKT) has been associated with improved long-term patient survival and shorter waiting periods. Due to favorable outcomes, ensuring equitable access to LDKT, regardless of residence, is critical.

Objective: We assessed whether rural residence impacts likelihood of receiving a LDKT within two years of waiting list (WL) registration, hypothesizing that recipients of less densely populated areas will be disadvantaged.

Methods: Organ Procurement and Transplantation Network WL data 1995-2018 were analyzed to summarize LDKT recipients on relevant demographic and clinical factors. We determined rurality using RUCA codes that account for population density and commuting habits to classify zip codes as rural/urban. The impact of rurality was evaluated using multiple logistic regression.

Results: 456,009 candidates were added to the kidney WL during the specified time; 18% received LDKT; 86% of whom were transplanted within two years of listing. 14% of LDKT recipients resided in rural areas, a percentage similar to the overall U.S. rural population. Univariate analyses indicated rural recipients were more likely to be older, white, insured by Medicare, have a high school education or less, and have a household income <$75,000 compared to urban recipients (p <0.0001 for all). After adjusting for associated covariates, the odds of LDKT within two years for rural candidates were higher than urban candidates (aOR 1.07, 95% CI 1.05, 1.10, p <0.0001).

Conclusion: Contrary to our hypothesis, rural residence does not disadvantage candidates in terms of receiving a LDKT within two years of WL registration.

Background: Historically, Black Americans have demonstrated greater risk for the development of end-stage renal disease, including following living kidney donation. Despite being only 13.6% of the total United States population, these individuals comprise nearly 30% of all kidney waitlist applicants.

Objective: To investigate the extent to which the Black living kidney donor (LKD) population has changed over time.

Methods: Our cohort included 8,935 Black living donors in the United States who had donated a kidney from 2005 to 2022. Data were extracted from the Organ Procurement and Transplantation Network (OPTN).

Results: Black LKDs are predominately female (60%), aged 18-49 (84%), and are more likely to donate to a relative (76.7%). While the number of Black kidney transplant recipients has increased from 23.9% (n=3,935) in 2005 to 28.9% (n=7,362) of the population in 2022, those with a living donor have decreased slightly from 14.9% (n=980) to 12.7% (n=745). There was a 51% decrease in Black LKDs, from 14.7% (n=876) of the donor population to 7.8% (n=431) during this time frame. As such, the number of living Black donors that donated to Black recipients declined in a similar fashion from 84.8% (n=831) to 45.6% (n=340). There was a decrease in donors accepted with an EGFR value of 30-59, suggesting that transplant programs were being more conservative when accepting Black donors.

Conclusion: The population of Black LKDs has decreased over time. Additional analysis is needed to determine the potential causes for the consistent and significant decline in the number of Black LKDs.

Background: Kidney transplant candidates' socioeconomic status (SES) influences transplant access. However, effects of race/ethnicity and SDOH on the relationship between candidate and community SES is unclear.

Objective: To examine impacts of candidate race/ethnicity and community SDOH on the relationship between candidate and residential SES characteristics.

Methods: We linked U.S. adult kidney candidates ever-waiting in 2020 to third-party SDOH data sources, and created scaled composite index scores for each U.S. Census tract from four parameters. Scores were quartile-ranked and linked to candidates’ residential addresses. We tested associations between SES factors and quartile using univariate and multivariable ordinal logistic regressions. Backwards-selection by Akaike Information Criterion determined the final model.

Results: Hispanic (2.541, 1.821-3.508) and other-race (1.535, 1.221-1.919) candidates had increase odds of living in a low SES Census tract than White candidates. Candidates with Medicaid (1.197, 1.096-1.308), Medicare (1.113, 1.067-1.16), and Self-Payers (1.398, 1.24-1.578) had increased odds of living in a low SES-tract than candidates with Private Insurance. Candidates with a voting record (1.201, 1.152-1.252) had increased odds of living in a low SES-tract than those without. Hispanic candidates (1.418, 1.233-1.631) with Medicaid had increased odds of living in a low SES-tract than White candidates with Medicaid. Black candidates with a voting record had increased odds of living in a low SES-tract (1.163, 1.097-1.234) than White candidates with a voting record.

Conclusion: Race/ethnicity influences the relationship between candidate and community SES factors, potentially impacting transplant access. Analysis of transplant candidates’ care access should consider the complexity of SES factors, SDOH and race/ethnicity.