Sommer E. Gentry

BACKGROUND AND OBJECTIVES: Variation in kidney transplant access across the United States may motivate relocation of patients with ability to travel to better-supplied areas. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We examined national transplant registry and U.S. Census data for kidney transplant candidates listed in 1999 to 2009 with a reported residential zip code (n = 203,267). Cox's regression was used to assess associations of socioeconomic status (SES), distance from residence to transplant center, and relocation to a different donation service area (DSA) with transplant access and outcomes. RESULTS: Patients in the highest SES quartile had increased access to transplant compared with those with lowest SES, driven strongly by 76% higher likelihood of living donor transplantation (adjusted hazard ratio [aHR] 1.76, 95% confidence interval [CI] 1.70 to 1.83). Waitlist death was reduced in high compared with low SES candidates (aHR 0.86, 95% CI 0.84 to 0.89). High SES patients also experienced lower mortality after living and deceased donor transplant. Patients living farther from the transplant center had reduced access to deceased donor transplant and increased risk of post-transplant death. Inter-DSA travel was associated with a dramatic increase in deceased donor transplant access (HR 1.94, 95% CI 1.88 to 2.00) and was predicted by high SES, white race, and longer deceased-donor allograft waiting time in initial DSA. CONCLUSIONS: Ongoing disparities exist in kidney transplantation access and outcomes on the basis of geography and SES despite near-universal insurance coverage under Medicare. Inter-DSA travel improves access and is more common among high SES candidates.

In kidney paired donation (KPD), incompatible pairs exchange kidneys so that each recipient receives a compatible organ. This modality is underutilized partly because of the difficulty of finding a suitable match among incompatible pairs. Alternatively, recipients with compatible donors might enter KPD arrangements in order to be matched with a donor predicted to give greater allograft durability or for other altruistic reasons. Using simulated donors and recipients, we investigated the impact of allowing recipients and their compatible donors to participate in KPD. For KPD programs of any size, the participation of compatible donor/recipient pairs nearly doubled the match rate for incompatible pairs (28.2% to 64.5% for single-center program, 37.4% to 75.4% for national program). Legal, logistical, and governmental controversies have hampered the expansion of KPD in the United States by delaying the creation of a national program. The inclusion of compatible pairs into small single-center pools could achieve match rates that would surpass that which could be realized by a national list made up of only incompatible pairs. This new paradigm of KPD can immediately be instituted at the single-center level, while the greatest gains will be achieved by incorporating compatible pairs into a national program.