Wait Time Modifications for Black Transplant Candidates Affected by Race-Based Kidney Function Estimation

Until 2021, national guidelines upheld race-based equations that assigned higher kidney function estimates to Black patients, delaying subspecialist referral and transplant waitlisting. In 2023, the Organ Procurement and Transplantation Network (OPTN) mandated that US kidney transplants programs submit wait time modifications for Black candidates who were disadvantaged by these equations.

To evaluate whether implementation of the OPTN wait time modification policy was associated with changes in kidney transplant rates by race and ethnicity in the US.

This quasi-experimental study analyzed an OPTN database of all US adult kidney candidates actively waitlisted between January 2022 and June 2025. Interrupted time series analysis evaluated the association of policy implementation with changes in transplant rates using generalized estimating equations adjusted for secular trends, time-varying and time-invariant confounding factors, and a first-order autoregressive covariance structure. Data analyses were performed from July 2024 to July 2025.

Implementation of the OPTN wait time modification policy in January 2023.

Kidney transplant rates by race/ethnicity and dialysis status, with outcome stratification by living and deceased donor kidney transplant (LDKT and DDKT).

The analysis included 181 314 kidney transplant candidates (mean [SD] age, 52.8 [13.1] years; 68 517 females [37.8%] and 112 797 males [62.2%]), including 56 344 Black candidates (31.1%) and 124 970 candidates of all other racial and ethnic groups (68.9%; including American Indian/Alaska Native, Asian, Hispanic/Latino, Native Hawaiian/Other Pacific Islander, White, multiracial, and unknown). From January 2023 through June 2025, 21 119 transplant candidates received wait time modifications, which added a median (IQR; range) of 1.7 (0.9-3.0; 0-21.2) years, and a total of 51 061 person-years of waitlist time. In interrupted time series analyses, among Black candidates, policy implementation was associated with an increase of 5.3 transplants per 1000 listings (95% CI, 3.5 to 7.0), with decreasing transplant rates thereafter (-0.10 transplants per 1000 listings per month; 95% CI, -0.17 to -0.03). Among all other candidates, implementation was associated with no significant change in overall transplant (0.6 transplants per 1000 listings; 95% CI, -1.8 to 0.7) and a parallel decreasing trend thereafter (-0.10 transplants per 1000 listings per month; 95% CI, -0.15 to -0.05). In secondary analyses, policy implementation was associated with increased overall and DDKT rates among Black preemptive and postdialysis candidates, no significant changes in LDKT for either group or DDKT for non-Black and/or Hispanic candidates, and a small secular increase in overall transplant rates.

This quasi-experimental study found that implementation of the wait time modification policy was associated with increased transplant rates among Black preemptive and postdialysis candidates. These findings provide evidence that remedying the harms of race-based medicine may be a promising approach to address racial kidney transplant inequities.