National Kidney Allocation System

Deceased donor kidneys for transplantation represent a scarce national resource. Therefore, allocation practices must be built on fair and equitable policies that ensure the best possible use of each kidney. The current kidney allocation policy was a decade in the making and required multiple rounds of public comment and revision to create a policy that balances utility and equity. The new allocation policy improves utility by maximizing life-years gained from kidney transplantation through longevity matching: pairing those patients with the longest expected life with kidneys expected to last the longest. It also, for the first time in kidney allocation, allocates kidneys based on need by prioritizing the highly sensitized patient and giving waiting time credit for time spent on dialysis prior to registration. Finally, the system attempts to both increase recovery and promote rapid placement of kidney from older donors. This is done through an opt-in system that attempts to allocate kidneys with a shorter duration of expected function and a higher Kidney Donor Profile Index to older recipients who would trade off a greater duration of function for more rapid transplantation. Coupled with the new allocation policy, the use of biopsy results from deceased donor grafts, characteristics of blood flow when placed on mechanical perfusion devices, and molecular biomarker measurement have the potential to expand the available pool of deceased donor kidneys. The new approach to kidney allocation in the United States provides a case study into how to thoughtfully and equitably distribute a scarce resource.