Lainie Ross is the associate director of the MacLean Center for Clinical Medical Ethics at the University of Chicago.
Three facts about end stage renal disease (ESRD) shape the kidney allocation debate. First, individuals with ESRD have two therapeutic options: dialysis or kidney transplantation. Second, virtually all individuals with ESRD, regardless of age, have a better quality of life and lower mortality and morbidity with kidney transplantation. Third, demand for kidney transplantation far exceeds supply.
The current allocation system is based mainly on time on the kidney waitlist. Critics object to the inefficiencies of the current system because a candidate who has a short life expectancy may be allocated a healthy deceased donor kidney that can be expected to outlive the recipient by years, maybe decades. The Kidney Committee has proposed a 20/80 allocation method. The "20" stands for the top 20 percent of kidneys (based on 10 donor traits that estimate expected graft survival) that are to be allocated to the top 20 percent of candidates (defined by four recipient traits—age, diabetes, dialysis time, and prior transplant status—that help determine post-transplant survival). The remaining 80 percent of kidneys will be allocated mainly on dialysis time, a variant of waiting time.
While the 20 percent rule will improve efficiency, it is unjust for three distinct reasons. First, it is arbitrary in its categorization of the top 20 percent of kidneys and candidates. The methodologies cannot distinguish between a 19 percent and 21 percent kidney or candidate. In fact, the methodologies cannot distinguish the top 20 percent from the next 20 percent. The designers claim their model will get it right about 75 percent of the time. Knowingly designing a model with a 25 percent error rate, when it determines who has greatest access to the best kidneys, is not morally justifiable.
Second, it is unjust because it singles out diabetes as the only health condition that reduces an individual's chance of being ranked in the top 20 percent of candidates. But individuals with type 1 diabetes are the candidates who are worst off because they have suffered a health problem since a young age. Egalitarian forms of justice require that any changes in allocation benefit those who are worst off. This proposal harms them.
Third, the proposal preferentially allocates kidneys procured in one area to candidates in that area. As the Kidney Committee data show, both the current and proposed allocation schemes would be more efficient and more equitable if kidneys were allocated using a broader primary geographic sharing scheme.
Justice requires that all have an equal chance of getting a kidney. This does not mean that they all must be eligible for all kidneys. For example, "prudential lifespan equity" permits differential treatment of individuals based on age provided that all persons are treated the same at different stages of life. So it is fair to give a 60-year-old candidate an older kidney, similar to the kidney he would have had had he not developed ESRD. Likewise the 20 year old should get a younger, healthier kidney. If all have an equal chance of getting a kidney, then an allocation system that consistently matches donors and kidneys by age over the lifespan is fair. But the new proposal characterizes those with longer and shorter life spans based on age and three other traits when other factors, like cardiovascular disease, better correlate with post-transplant survival. The arbitrary and unfair characterization of the top 20 percent of candidates renders the proposal ethically unacceptable.
Changes are in order, but the new proposal has it wrong.