Realizing the Promise of Equity in the Organ Transplantation System (2022) / Chapter Skim
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5 Saving More Lives and Enhancing Equity with Deceased Donor Organ Allocation Policies
5 Saving More Lives and Enhancing Equity with Deceased Donor Organ Allocation Policies
Pages 117-152
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From page 117... ...
Final Rule directs the Organ Procurement and Transplantation Network (OPTN) to design organ allocation policies "to achieve the best use of donated organs.1 Specifically, the OPTN must rank candidates from "most to least medically urgent" while "taking into account...that life-sustaining technology allows alternative approaches." However, allocation systems differ by organ.
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From page 118... ...
medical urgency and survival benefit; waiting time; distance from donor Similar to heart transplant, the transplant team also reviews the patient's hospitalh medical history to determine eligibility for transplant. A candidate who smokes must also cease smoking and be nicotine free for several months Max organ preservation time: 4–6 hours before being allowed on the waiting list.g Once a candidate is deemed eligible, they are added to the UNOS waiting list.
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From page 119... ...
. waiting list.n Multiorgan Candidates are evaluated by the transplant team according to the policies Multiorgan transplant specific policies Kidney-alone transplant governing the types of organ transplants they need.
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From page 120... ...
. As discussed in the section later in this chapter on survival benefit, it is not clear that this is a disparity with respect to the organ transplantation system overall, but it may affect patient outcomes on an individual or regional level.
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From page 121... ...
Kidney-alone transplant candidates may be disadvantaged by multiorgan allocation policies, where the "next sequential" candidate who would have received a donated kidney had it not gone to a multiorgan transplant recipient tended to be younger, more highly sensitized, and more likely to identify with a minority group (Westphal et al., 2021)
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From page 122... ...
Understanding that 14 to 20 percent of deceased donor kidneys that were eventually transplanted were first offered to one or more deceased candidates (Husain et al., 2018) is a situation that undermines public trust in the organ transplantation system.6 Updating patient data can improve the organ offer process, and make it possible for the right organ to get to the right recipient in a timely manner.
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From page 123... ...
The OPTN Final Rule in 1998 sought to address some of these geographic disparities in deceased donor organ allocation. Specifically, the Final Rule directs that organ allocation policies not be based on a transplant candidate's place of residence or listing except to the extent required by other requirements of the Final Rule and that allocation should achieve equitable allocation among patients, including through the distribution of organs over as "broad a geographic area as feasible" under the other allocation policies.7 The ensuing controversy prompted Congress to request a study from the Institute of Medicine (IOM)
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From page 124... ...
The framework aims to eliminate fixed geographic boundaries currently used to separate groups of candidates based on distance between donor hospital and transplant hospital. Prior deceased donor organ distribution frameworks have considered patient characteristics in a defined sequence, whereas continuous distribution will create a composite score that considers multiple patient and donor attributes all at once with an overall score that includes medical urgency, posttransplant survival, candidate biology, patient access (such as pediatric or prior living donor)
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From page 125... ...
The kidney and pancreas policy completed its public comment phase at the end of September 2021,9 and it will go to the board of directors in 2022 for review. Continuous distribution policy development for liver and intestine will begin next, anticipated in 2022, followed by heart and vascularized composite allotransplantation (VCA)
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From page 126... ...
. Another study compared the use of short-term mechanical circulatory support -- an intervention as a bridge to transplant -- before and after the 2018 heart allocation changes and found the use of this circulatory support increased and continued to expand following the allocation policy changes (Cascino et al., 2021)
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From page 127... ...
It also estimates how long a patient will survive follow TABLE 5-3 Measurements of Organ Function and Recipient Suitability Typically Considered in Liver Allocation Decisions Allocation Scoring System Factors and Variables Model for End-Stage Liver Disease (MELD) Serum creatinine Liver (adult)
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From page 128... ...
For heart transplant candidates that also need a lung transplant, the heart is matched first and the lungs come from the same deceased donor. If a lung transplant candidate also needs a heart transplant, the lungs are matched first but the donated heart is first offered to transplant candidates in "allocation classifications 1 through 12." In June 2021, the OPTN clarified policies surrounding multiorgan allocation to resolve issues with variation in OPO interpretations as to the prioritization of organ offers for the second required organ (kidney or liver)
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From page 129... ...
As stakeholders in the organ transplantation system move toward a more equitable system that better addresses the needs of minority and underserved populations who have experienced limited access to transplantation and worse transplant outcomes, reevaluating the use of race in eGFR and other clinical equations (e.g., KDPI) is warranted.
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From page 130... ...
While the organ transplantation system moves toward a vision of non-race-based measures in assessing kidney function, some have suggested that • Changing practice guidelines will require significant education efforts within health systems and consideration of the increased number of patients that may be classi fied with chronic kidney disease (Ahmed et al., 2021)
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From page 131... ...
The U.S. kidney allocation system currently gives priority "waiting time" points for years on dialysis but simultaneously allows unlimited predialysis "waiting time" points to accumulate.
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From page 132... ...
. The revisions to the kidney allocation system also prioritized deceased donor kidney transplantation for candidates with long dialysis durations.
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From page 133... ...
It is possible that removing pre dialysis wait time from the kidney allocation system could reduce structural racism in kidney allocation and save more lives. It would be important that any policy change not ban pre emptive deceased donor kidney transplants, but rather represent that these transplants may confer less benefit than transplanting patients with significant dialysis time.
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From page 134... ...
While this committee is not recommending that access to the deceased donor kidney waiting list be limited to only those who have started dialysis, the committee is recommending that predialysis waiting time should be discontinued as a basis for accumulating waiting time points. This change would ultimately save more lives in a fairer and more equitable manner by eliminating the current preferential access to deceased donor kidneys for individuals able to gain timely access to referral for transplant and the transplant waiting list.
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From page 135... ...
Promote posttransplant kidney function for candidates with the longest estimated Utility posttransplant survival who are also the most likely to require additional transplants because of early age of ESRD onset. Minimize loss of potential functioning years of deceased donor kidney grafts Utility through improved matching.
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From page 136... ...
. France tends to use donated kidneys with higher KDPI, largely driven by use of organs from older donors, and transplanted patients still realize significant survival benefit.
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From page 137... ...
Maximizing survival benefit may lead to the selection of the most medically urgent16 candidates that still have high likelihood of posttransplant survival. The survival benefit of deceased donor organ transplantation has been quantified in lung (Vock et al., 2017)
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From page 138... ...
However, there may be other ways to estimate survival benefit that are less likely to favor younger, healthier candidates and that could improve the efficiency of kidney allocation. First, by focusing on a finite time interval, it is possible that more medically urgent candidates with high waiting list mortality will derive increased benefit from a transplant relative to remaining on the list than young healthy candidates whose waiting list mortality is more similar to their posttransplant survival.
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From page 139... ...
Therefore, minorities who enter the waiting list with almost twice the dialysis time could have a higher likelihood of receiving a kidney offer if allocation is based on survival benefit rather than 1-year posttransplant survival, for which their rates are lower and lead to increased racial disparity because of existing allocation algorithms. Conclusion 5-13: Black candidates enter the kidney transplant waiting list with double the length of dialysis time than white candidates and as a consequence have increased medical urgency as evidenced by their increased risk of mortality without transplantation.
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From page 140... ...
Furthermore, the top 20 percent most urgent candidates experience a greater benefit from lower KDPI kidneys than the top 20 percent EPTS candidates. For both a 15 percent and 85 percent KDPI kidney, allocation to the top 20 percent most medically urgent candidates produces large increases in survival benefit relative to the longevity matching (top 20 percent EPTS recipients)
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From page 141... ...
. Focusing on posttransplant survival does not account for health lost while waiting for transplant -- which is particularly important for medically urgent candidates who are at higher risk of death or deterioration and who tend to lose health more rapidly -- and reduces the efficiency of deceased donor kidney allocation.
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From page 142... ...
The SRTR builds and updates simulated allocation models (SAMs) to model alternative organ allocation policies and predicted outcomes for patients on the waiting lists for each organ type.
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From page 143... ...
The data on which some allocation algorithms are based are not frequently updated. For example, the current KDPI model is derived from deceased donor kidney transplants from 1995 to 2005 (OPTN, 2020b)
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From page 144... ...
The specific contract ensures that • the national organ waiting list is maintained, • the information technology (IT) system operates to match organs with patients, • system performance is monitored and based on transplant data gathered, and • organ allocation policies are developed (Proctor, 2019)
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From page 145... ...
Healthcare.gov is a recent example in a long line of similar examples where government contracting for large IT systems resulted in initial failures that took time to overcome. The current organ transplantation IT system performs key functions every hour, and enables the matching of available organs with wait-listed candidates, using complex algorithms associated with transplant allocation for all organ types.
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From page 146... ...
Recommendation 8: Modernize the information technology infrastructure and data collection for deceased donor organ procurement, allocation, distribution, and transplantation. HHS should ensure that the OPTN uses a state-of-the-art information technology infrastructure that optimizes the use of new and evolving technologies to support the needs and future directions of the organ transplantation system.
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From page 147... ...
2014. External validation of the esti mated posttransplant survival score for allocation of deceased donor kidneys in the United States.
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From page 148... ...
2018. Association of the kidney allocation system with dialysis exposure before deceased donor kidney transplantation by preemptive wait-listing status.
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From page 149... ...
2005. Deceased-donor characteristics and the survival benefit of kidney transplantation.
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From page 150... ...
2016. Survival benefit from kidney transplantation using kidneys from deceased donors aged ≥75 years: A time-dependent analysis.
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From page 151... ...
2021. Association of the estimated glomerular filtration rate with vs without a coefficient for race with time to eligibility for Kidney Transplant.
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