At a glance
What is current practice and why address it?
The current system allocates lungs by placing candidates into categories that are considered and prioritized in sequence. When reviewed in sequence, sometimes candidates are placed on the side of a hard boundary that would stop them from being prioritized further on the match run. This proposed framework will consider multiple patient factors all at once with an overall score. This overall score includes not only medical urgency and patient outcomes, but also factors such as biologic match and efficiency of organ transport. This paper is an update from the Lung Committee and a request for community feedback through an exercise that will help inform the Committee’s work. Read more about continuous distribution.
Update on the Continuous Distribution of Organs Project
Dr. Erika Lease, Chair of the OPTN Lung Transplantation Committee, reviews the Update on the Continuous Distribution of Organs Project request for feedback item.
Terms you need to know
- Attribute: Factor used to classify, sort, and prioritize candidates. For example, in this concept paper, lung allocation attributes include medical urgency, travel time, ischemic time, blood type compatibility, and others.
- Composite Allocation Score: The total number of points assigned to a candidate on the wait list, which would determine their rank on a match run.
- Rating Scale: Method used to calculate number of points awarded to candidates for each attribute. For example, if everything else is equal, should a candidate with twice as much medical urgency as another receive twice as many points? Applying the rating scale to each candidate’s information and combining it with the weight of the attribute results in an overall composite score for prioritizing candidates.
What’s been done since the last update?
- Composite Allocation Score components determined
- 5 goals make up the score
- Prioritize candidates who are expected to survive at least one year after receiving a transplant (Post-Transplant Survival)
- Prioritize sickest candidates first to improve waitlist mortality (Medical Urgency)
- Increase transplant opportunities for patients who are medically harder to match (Candidate Biology)
- Increase transplant opportunities for patients under the age of 18 and patients who previously donated an organ/part of an organ (Patient Access)
- Consider resources required to match, transport, and transplant an organ (Placement Efficiency)
- Each goal includes specific patient attributes
- Each attribute will have a rating scale
- Candidates receive points for each attribute
- These points combine into a total score for the candidate
- 5 goals make up the score
- The Committee needs community feedback on how to prioritize the attributes
- How much weight given to each attribute has not been determined
- There is no definitive “right” answer
- The Committee is inviting the donation and transplant community to participate in an exercise to help inform its decisions on the importance, or “weight”, of each attribute
What this concept could accomplish
- Provide a more complete approach to matching candidates and donors
- Remove hard boundaries that prevent candidates from being prioritized further on the match run
- Establish a system that is flexible enough to work for each organ type on the match
What this concept wouldn’t do
- This paper is not a proposed policy change
Themes to consider
- Attributes identified to be included in score
- Additional attributes that should be included
- Weight of attributes in final score
Status: Public Comment
Sponsoring Committee: Lung Transplantation Committee
Strategic Goal: Provide equity in access to transplants
Anonymous | 08/13/2020
Coming from a lung recipient family, this is a step toward a welcome change to removing hard geographic boundaries from lung allocation, and this will be especially beneficial for highly sensitized patients. The current allocation exceptions for highly sensitized patients aren't sufficient, and incorporating CPRA would help ensure access.
Anonymous | 08/13/2020
Would give more weight to patient acuity and equal to the remainder.
Steven Potter | 08/23/2020
Laudable concept. The various weights attributed to the goals that form the composite allocation score will be critically important and debate over this will likely be contentious. Of the composite elements, placement efficiency seems to be the least important and should be given the least weight. The aura concept seems extremely problematic, and the committee's apparent lack of favor at this time for the aura approach to allocation is noteworthy and correct. As the committee has noted, the aura approach is in violation of a long held paradigm of placing organs with candidates, not with programs, and the committee should be lauded for discarding the aura approach.
Region 4 | 08/26/2020
During the discussion, one attendee commented that with increasing use of OCS systems, maybe distance should be less a priority. If an individual center does not have OCS, they can still decline. A couple attendees noted that the request for feedback identifies reasoning for some but not all excluded attributes and thought that there should be reasoning documented for all the exclusions. One attendee recommended the use of Transplant Benefit as a metric on the Comprehensive Allocation Score.
Region 5 | 08/28/2020
Region 5 had the following comments: • Doing away with miles puts responsibility on transplant centers to calculate cold ischemic time. • Transplant outcomes need to be considered. Taking away distance could negatively affect cold ischemic times and transplant outcomes • Will the committee give any consideration for the use of lung profusion devices to negate some of the efficiency and distance concerns? • Modeling will bolster community confidence. • Support that you are looking at cost of flights in both direct flight cost and time. • This system provides for a more equitable allocation of organs • I think COVID should be a separate category and outcomes tracked carefully
OPTN Pancreas Transplantation Committee | 09/03/2020
The Pancreas Committee thanks the OPTN Lung Transplantation Committee for the opportunity to review their Continuous Distribution update. The Committee provided the feedback below: • The Committee inquired about the data being used to weigh attributes and if it has been a straight forward process. There is clinical data for some attributes, which should be direct, but there is no data when measuring the importance between attributes. • The Committee expressed concern that other organ groups have put more emphasis on access to transplant or decreasing waitlist mortalities than post-transplant survival. The Committee inquired whether there was any additional feedback on other attributes that should be considered or of importance to the lung organ group.
LifeGift | 09/07/2020
LifeGift supports the continuous distribution concept and its framework of the 5 goals in order as written in the proposal material. It reduces the impact of accidents of geography and is generalizable to all organs. It will be important to consider the increasing presence of new preservation devices and modalities in the fifth goal. These devices allow for longer preservation times if the organ is transported on device and thus distance attribute points assignments will need to be modified for this welcomed advancement in organ preservation.
Region 7 | 09/10/2020
Region 7 had the following comments about this project: • An attendee agreed that this is an important concept to develop. They are pleased that the lung committee is taking the lead on this and stated this should be expanded to all organs. They agreed that this project makes the most sense to balance travel times with addressing geographic disparities. • One attendee suggested emphasizing placement efficiency for DCD and marginal BD lungs. They added that offering these organs to every patient on the wait list is not a good use of resources and results in lost opportunities. • An attendee commented that pediatric status should be given a higher weight due to conditions such as a child's failure to thrive while waiting. • Three attendees commented on cost, ex vivo perfusion and sensitized candidates with the continuous distribution model. One stated that the committee should consider looking at cost/efficiency consideration and proximity to major airports (less relevant for more highly time sensitive organs like lung). They added that they would not recommend using this as a factor for kidney allocation it would discriminate against smaller market transplant centers.
Histocompatibility Committee | 09/10/2020
The Committee is overall supportive of the work in progress to create an organ allocation system based on continuous distribution. The Committee is concerned that sensitized transplant candidates, especially lung candidates, may need unique considerations per candidate beyond what a weighted score or extra points may offer. As the workgroup considers incorporating CPRA into allocation, please ensure the Histocompatibility Committee has the opportunity for timely and frequent input. Allocation of organs should be approached with value or equity at the forefront, but with preservation of a center’s ability to make final decisions about a recipient’s transplant. The Committee looks forward to being an impactful stakeholder in collaborating in this long term effort.
Region 3 | 09/15/2020
Comments: Ex vivo lung perfusion and onsite organ recovery centers were mentioned as factors that should be considered in the model. A member addressed placement efficiency and stated that placement efficiency isn’t just about the cost of transporting an organ, which others reiterated. It was recommended that the match run should take into account a transplant center’s acceptance history; OPO perspective is important for the prioritization exercise and understanding placement efforts will be critical as all of the organ specific committees work on continuous distribution. Another member stated that looking at travel efficiency and cost is important and should be done consistently when organ allocation is changed. Follow up comments added that it will be important that the attributes are regularly evaluated and are able to be adjusted as technology and procurement practices advance. The recent increase in local recovery in response to COVID was mentioned as a change and that if the practice continues, it could increase efficiency. Lung placement was also mentioned as a consideration since OPOs vary in how much time they will invest in lung donor management and consider having OPOs review successful lung placement and why lungs are not placed. Additional comments submitted online during meeting: • I reiterate comments regarding placement efficacy. Time is LIFE and the longer the allocation process takes, the more viable organs are buried. This needs to be a priority in the points system • Support the OPTN lung committee's work on this continuous distribution of organs project • Significant consideration should be given not just to one year survival, but also longer term survival • This is important in not just Lung, but all solid organ transplant in my opinion. • Regarding PRA or sensitization status are you only considering points for cPRA or have more granularity regarding points by loci like DQ? • Seems guidelines will enhance distribution. • Hard to justify prioritizing proximity, travel costs in lung while the cost / travel / recovery / efficiency concerns were not acknowledged during liver allocation changes. Liver is a much more common transplant with much greater overall costs and impact. Consistency in approach should be an aim among different organ allocation schemes (not all same, but at least consistent) • I have concern with this continuing to negatively impact the ability of OPO's to get lungs placed efficiently and drive up expenses and fees • Priority should be on the patient and not the ease of OPO placement • What is the current death rate on the waitlist by specific lung disease? • Has the committee given any consideration for how allocation would be affected when lung is involved with a multi-organ situation; i.e. heart-lung, where heart 'pulls' lung, and can potentially pull from a high LAS recipient or lung-liver where there isn't a very clear path?
OPTN Operations and Safety Committee | 09/18/2020
Update on the Continuous Distribution of Organs Project The Operations and Safety Committee thanks the OPTN Lung Transplantation Committee for their efforts in developing this public comment proposal for the Update on the Continuous Distribution of Organs Project. The Committee supports the discussion around travel efficiency attributes. It was suggested to consider the complexity of travel as a way to analyze the failure aspect of placement efficiency. Additionally, the Committee suggested reviewing other organs’ travel efficiencies.
Region 8 | 09/22/2020
Comments: A member provided feedback that they are concerned about candidates under the age of 12 and competition with older pediatrics and also that further segmentation of pediatric candidates is not scientific and that the committee should clearly articulate their intent to ensure patients under 12 are not disadvantaged. One member commented that this should have a significant impact on diminishing unnecessary travel. The committee was asked to carefully review the impact of these changes on the financial viability of small programs and programs in less populous areas and, if possible, to consider how patient's insurance access/options disadvantages some populations, particularly the Medicaid populations as part of this framework. A comment was made that surgeon availability and travel time are key factors that could be really important and may be difficult to track. One member made a comment that this could increase cost and complexity. Several comments were made in general support of the project.
American Society of Transplantation | 09/24/2020
The American Society of Transplantation supports the Continuous Distribution of Organs Concept which uses 5 components in a Composite Allocation Score to overcome long-standing problems of accidents of geography created by arbitrary geographic borders. We acknowledge and appreciate the timely actions taken by UNOS to address evolving issues and needs within the transplant and donation community related to the Continuous Distribution Project. However, we do also want to ensure that young pediatric candidates are not disadvantaged (see comments below). We found the document to be extremely helpful in understanding the process and steps involved in determining the goals and attributes which are being considered for the Composite Allocation Score. The discussion on why or why not specific attributes were being used was transparent, not difficult to follow the reasoning and based on prior literature. We support the dissolution of hard boundaries in the current classification system and agree with the proposed attributes that make up the composite allocation score. The Priority exercise was helpful to understand this process. The AST encourages all lung transplant professionals to complete this survey. We believe there is value in other solid organ professionals’ review of this exercise, as although the attributes may be different from lung, the goals remain similar for all organs. At the direction of the HHS secretary in response to a court challenge several years ago, the most recent change to the pediatric donor sequence in the lung allocation policy prioritized access for pediatric lung candidates under 12 to adolescent donor organs (including priority over other adolescents within 1000 nm of the donor) while protecting priority for under 12 candidates to access under 12 donor organs. In the proposed continuous distribution framework, candidates under 12 will lose both sets of priorities. Although the proposal outlines steps intended to mitigate these changes (assigning pediatric lung candidates under 12 medical urgency and post-transplant survival scores based on historical cohorts, giving pediatric candidates as a group additional points and giving smaller patients additional points based on the proportion of donors with suitably sized organs), it remains to be seen whether modeling will verify that these changes will not negatively impact access to transplant and waiting list outcomes for children under 12. Because the numbers will likely be too small to reach statistical significance, gathering sufficient evidence to make a change post implementation may be challenging. To ensure that this project continues to move forward in a timely manner, we recommend that the committee consider including in their modeling requests alternate constructs that protect access for this small but vulnerable patient population. The conversion of attributes into points should result in marginal negative impacts to organ utilization rates, waiting list mortality rates, and post-transplant survival. As described currently, the fifth goal, Placement Efficiency, is of particular importance to the Society’s Recovery and Preservation Community of Practice. It is and will be increasingly important to allow for flexibility of the nautical mileage attribute as a proxy for ischemic time as more preservation devices are being used to extend preservation time and thus distance, if the organ is going to be transported on device. Careful deliberation with community involvement on how to appropriately weight this factor fairly and ensuring future ability to revisit frequently as perfusion technologies evolve, is requested by some of our COP members. Additionally, in situations where initially declined organs are sent to regional perfusion centers for repair or rescue treatment, the distance starting point for the subsequent allocation of the organ after treatment should be from that perfusion center’s location. This is important to accurately calculate where the organ will be traveling from and also to limit disincentives for utilizing regional perfusion centers as a key strategy for increasing the availability of transplantable organs.
Region 1 | 09/24/2020
Comments: Members stated the committee is doing an excellent job presenting the material and the work will serve as a good template for other organ types. One member is in favor of including the anticipated duration of graft survival. One member stated that the Policy Oversight Committee is helping to orchestrate Continuous Distribution and the work of the lung committee will inform the other organ-specific committees.
Region 2 | 09/25/2020
Comments: • One commenter noted that the Lung Committee should be lauded for leading this OPTN initiative for all organ transplants as our transplant system migrates from a local defined matching and allocation system to a more national and continuous distribution strategy to improve fairness, equity, efficiency, and cost-effectiveness in the spirit of NOTA and the Final Rule. • Another commenter agreed that this is really impressive work by the Lung Committee and it is a very thoughtful and cogent approach to difficult and sometimes conflicting allocation factors. • Another commenter stated that as the work continues across all organs, patient predicted outcomes should be part of the allocation system. • Another attendee commented that they support the idea to encourage less geography as a factor guiding allocation. However, the pressures to consider expenses needs to be taken into consideration. As organs are traveling farther distances, the cost of transplants is rapidly rising. • In addition, another attendee agreed that distance and travel include cost concerns, but air travel is a transplant team safety concern, especially in unpredictable and inclement weather. The financial proxy considerations does not consider these safety concerns. • Lastly, one attendee noted that this is excellent work by the Lung Committee and the process should be replicated as all organs move to a Continuous Distribution model. After implementation, it will be very important for the committee to develop extensive education for patients, families, donor families, and the general public to help explain this new distribution model.