Impact of the expanded criteria donor allocation system on the use of expanded criteria donor kidneys

Background. The U.S. Organ Procurement and Transplantation Network recently implemented a policy allocating expanded criteria donor (ECD) kidneys by waiting time alone. ECD kidneys were defined as having a risk of graft failure >= 1.7 times that of ideal donors. ECDs include any donor >= 60 years old and donors 50 to 59 years old with at least two of the following: terminal creatinine > 1.5 mg/dL, history of hypertension, or death by cerebrovascular accident. The impact of this policy on use of ECD kidneys is assessed. Methods. The authors compared use of ECD kidneys recovered in the 18 months immediately before and after policy implementation. Differences were tested using t test and X-2 analyses. Results. There was an 18.3% increase in ECD kidney recoveries and a 15.0% increase in ECD kidney transplants in the first 18 months after policy implementation. ECD kidneys made up 22.1% of all recovered kidneys and 16.8% of all transplants, compared with 18.8% (P < 0.001) and 14.5% (P < 0.001), respectively, in the prior period. The discard rate was unchanged. The median relative risk (RR) for graft failure for transplanted ECD kidneys was 2.07 versus 1.99 in the prepolicy period (P = not significant); the median RR for procured ECD kidneys was unchanged at 2.16. The percentage of transplanted ECD kidneys with cold ischemia times (CIT) < 12 hr increased significantly; the corresponding percentage for CIT >= 24 hr decreased significantly. Conclusions. The recent increase in ECD kidney recoveries and transplants appears to be related to implementation of the ECD allocation system.