Strategies to Guide Preemptive Waitlisting and Equity in Waittime Accrual by Race/Ethnicity

Abstract

Background Use of eGFR to determine preemptive waitlisting eligibility may contribute to racial/ethnic disparities in access to waitlisting, which can only occur when the eGFR falls to ≤20 ml/min per 1.73 m2. Use of an alternative risk-based strategy for waitlisting may reduce these inequities (e.g., a kidney failure risk equation [KFRE] estimated 2-year risk of kidney failure) rather than the standard eGFR threshold for determining waitlist eligibility. Our objective was to model the amount of preemptive waittime that could be accrued by race and ethnicity, applying two different strategies to determine waitlist eligibility. Methods Using electronic health record data, linear mixed models were used to compare racial/ethnic differences in preemptive waittime that could be accrued using two strategies: estimating the time between an eGFR ≤20 and 5 ml/min per 1.73 m2 versus time between a 25% 2-year predicted risk of kidney failure (using the KFRE, which incorporates age, sex, albuminuria, and eGFR to provide kidney failure risk estimation) and eGFR of 5 ml/min per 1.73 m2. Results Among 1290 adults with CKD stages 4–5, using the Chronic Kidney Disease Epidemiology Collaboration equation yielded shorter preemptive waittime between an eGFR of 20 and 5 ml/min per 1.73 m2 in Black (−6.8 months; 95% confidence interval [CI], −11.7 to −1.9), Hispanic (−10.2 months; −15.3 to −5.1), and Asian/Pacific Islander (−10.3 months; 95% CI, −15.3 to −5.4) patients compared with non-Hispanic White patients. Use of a KFRE threshold to determine waittime yielded smaller differences by race and ethnicity than observed when using a single eGFR threshold, with shorter time still noted for Black (−2.5 months; 95% CI, −7.8 to 2.7), Hispanic (−4.8 months; 95% CI, −10.3 to 0.6), and Asian/Pacific Islander (−5.4 months; −10.7 to −0.1) individuals compared with non-Hispanic White individuals, but findings only met statistical significance criteria in Asian/Pacific Islander individuals. When we compared potential waittime availability using a KFRE versus eGFR threshold, use of the KFRE yielded more equity in waittime for Black (P = 0.02), Hispanic (P = 0.002), and Asian/Pacific Islander (P = 0.002) patients. Conclusions Use of a risk-based strategy was associated with greater racial equity in waittime accrual compared with use of a standard single eGFR threshold to determine eligibility for preemptive waitlisting.