A Recipient Risk Score for Deceased Donor Renal Allocation

Background: The current shortage of deceased donor kidneys makes it difficult to design a kidney allocation scheme that balances optimal utility with supply. The aim of this study is to derive a recipient risk score (RRS) that could be used with the deceased donor score (DDS) to maximize the total number of years of renal allograft function as a means to improve allocation. Methods: We retrospectively reviewed 47,535 adult recipients of deceased donor renal transplants between 1995 and 2002 from the United Network for Organ Sharing Standard Transplant Analysis and Research Files. Multivariable Cox regression models were used to derive an RRS and estimate recipient and graft survival as a function of RRS. Annual rates of organ supply and recipient demand for deceased donor kidneys were estimated from expectancy data and expressed in renal years (years provided by a functioning kidney allograft). Renal-year analyses were used to optimize allocation. Results: The strongest predictors of recipient survival after transplantation used in the RRS were recipient age, history of diabetes mellitus, history of angina, and time on dialysis therapy. When used with DDS, RRS provided a utility-based allocation system for deceased donor kidneys that theoretically increased the annual (2002) rate of supply by 15%. Conclusion: The RRS is a practical system that, when combined with a method to assess donor organs, such as DDS, may improve deceased donor renal allocation.