Problems of Equity With Organ Allocation to Multi-organ Transplant Recipients
Although multiple definitions of fairness—or equity—have been proposed, organ allocation via MOT poses problems within all of them. Drawing on concepts articulated by the philosopher John Rawls, two main principles may be applied to promoting distributive justice for transplant candidates. First, the Equality Principle states that individuals who can derive similar benefit from an organ ought to have equivalent access to it. Allocation based on a lottery, or less optimally, a first-come and first-served system, might satisfy this principle. Instead, current procedures allow MOT recipients to "jump ahead in line" and receive higher priority for their additional organs than others who may receive similar or greater benefit.
Rawls' Difference Principle allows for inequalities in allocation only if the imbalances would benefit the least advantaged, or "worst off". The challenge for an equity analysis is that many factors contribute to making one "poorly off"—for example, mortality risk, morbidities, the length of time waiting for organs or sensitization. The Fair Innings approach suggests that the younger a transplant candidate is, the worse off that candidate is (having enjoyed fewer years of healthy life).
Thus, it is unclear that MOT candidates are "worse off" in terms of need for their additional organs compared to all other candidates for those organs. For example, although adult MOT recipients are among the worst off as measured by overall illness acuity, children with end-stage organ disease who may never reach adulthood may be even more "worse off." As a second example, highly sensitized kidney transplant candidates have extremely reduced access to transplant because of incompatibility with most donors. As a third example, patients with prolonged waiting times for a single kidney face elevated risks of mortality and reduced quality of life. Yet candidates in these three examples often have lower priority for that kidney than an SLK or SPK candidate.
Another inequitable element of current allocation is the absence of standard criteria for MOT eligibility. Using the SLK example, no minimal criteria for the severity of kidney dysfunction needs to be satisfied to qualify. As a result, transplant centers differ greatly in how they determine SLK listing eligibility and the percentage of liver transplant candidates who receive SLKs varies from 4% to 12% across US regions (Figure 2). Variation in SLK practices may lead to heterogeneous access to kidneys, such that patients listed in regions with high rates of MOT have greater diversions from their organ supply.
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Figure 2.
Geographic variation in simultaneous liver–kidney (SLK) transplant as a percentage of all liver transplants. Donor service areas are geographic areas of the United States served by local organizations that procure organs donated for transplantation.