Kidney transplant data from the first four weeks after implementation of the new kidney allocation system (KAS) suggest that a number of key outcomes are meeting expectations, while other trends merit continued close monitoring. These are detailed in a report released by UNOS.
Please note that early data may not be a reliable indicator of trends that will either change or become more pronounced as additional kidneys are recovered and transplanted. Data will be analyzed at regular intervals to continue to study the performance of the allocation system and identify areas of potential improvement.
Compared to trends before KAS implementation in early December 2014, the early results indicate three major changes that are consistent with key performance goals for the new system:
- a seven-fold increase in transplants for patients with the highest immune system sensitivity (a CPRA score from 99 to 100 percent)
- an increase in transplants for recipients outside the local donation service area, from about 20 percent before KAS implementation to about 35 percent
- drop in the number of transplants where the donor age was 15 years or more different from the recipient age
While recipients over age 50 accounted for 56 percent of all transplants, there appears to be a moderate shift in the number of transplants by candidate age, with a slight increase in recipients between 18 and 49 and a slight decrease in those over age 50. Transplants among recipients younger than age 18 decreased in the first few weeks, a trend that will be monitored closely. In addition, in the early weeks, fewer transplants occurred where the donor and recipient had no HLA antigen mismatches.
While additional data may reveal more significant trends, the early experience did not show major changes in a number of measures, including:
- distribution of transplants by the race/ethnicity of candidates
- rate of kidney transplantation or registration of new transplant candidates
- rate of kidneys being recovered for transplantation
- discard rate of kidneys
Kidney transplant programs were generally well prepared in updating candidate data for the KAS transition, such as information needed to calculate candidates’ estimated post-transplant survival (EPTS) scores. One notable observation, however, is that only 2 percent of candidates with blood type B had been listed as willing to accept kidneys with other acceptable subtypes (A2 or A2B), a trend that will continue to be investigated.