The lung organ type is the first organ type to work through establishing continuous distribution as its new framework for allocation. The work started with the Thoracic Committee in winter 2019 and is continued by the Lung Transplantation Committee that was formed in summer 2020.
Here you will find results of the work organized by the steps to build and implement the framework.
1. Identify attributes
The Lung Committee considered several attributes before deciding those that would contribute to the composite allocation score. The identified attributes will align with NOTA and the OPTN Final Rule. In addition, any attribute that is based in part on a candidate’s location or listing is only permitted to the extent required by another regulatory factor. The Committee began with the attributes that are in current policy then considered additional attributes suggested during 2019 public comment.
- 2019 lung concept paper (PDF; 8/2019)
- Update on the continuous distribution of lungs project, request for feedback paper (PDF; 8/2020)
2. Assign valuesPrioritize attributes against each other:
The specific weight of each attribute determines how much influence each attribute will have toward the overall score. This step has two parts:
Community input is being collected through a method called the Analytic Hierarchy Process or AHP. The AHP exercise shows each participant a pair of attributes that will be used to prioritize candidates. The participant must decide if all else is considered equal, which attribute is more important than the other when prioritizing a candidate for an organ.
- August 2020 community AHP results (PDF; 10/2020)
Compare to “current state” through a revealed preference analysis. A revealed preference analysis involves looking at mathematical trends to review how multiple decisions have been made. For example, how important was distance compared to waiting time when a decision was made between two candidates? The analysis will take the current system and create a baseline to be measured against.
- Revealed preference analysis (PDF; 1/2021)
For each attribute that will be considered toward the overall score, the Lung Committee will decide how to assign points to candidates according to differences in the attribute. For example, how many points do we give to blood type A versus O? 100 miles versus 1,000 miles?
3. Build FrameworkConduct sensitivity analysis
A sensitivity analysis is an analysis used by statisticians to change a single variable slightly to measure the impact on an outcome. For continuous distribution, a sensitivity tool has been built to evaluate continuous distribution of lungs. For example, if a change is made to the weight of any attribute, the new match run will be shown as the outcome.
Develop the composite score will be a combination of decided weights and rating scales.
4. Modeling and analysis
The Scientific Registry of Transplant Recipients (SRTR) will take proposed allocation policies and model them to determine the impact on candidates. These results will be produced in a report to help identify any potential unintended consequences or harmful outcomes for these example groups. These results will estimate the benefit of the new proposal and inform any needed improvements. The modeling request for the SRTR will be submitted in winter 2020.
- SRTR modeling results:
- Round 1 – (PDF; 2/2021) | Round 2 - (PDF; 5/2021) | Round 2 Addendum - (PDF; 7/2021)
- The impact of extending follow-up for the PTAUC model from 1 year to 5 years after transplant (PDF; 2/2021)
5. Public comment on policy proposal
Considering community input, modeling and analysis, and committee project work, propose a new composite score as a policy proposal for public comment.
- Continuous distribution of lung proposal – expected fall 2021 public comment
6. Board approval
The Board of Directors will review the proposal, OPTN and SRTR materials, and public comments, and consider the proposal in light of the requirements of the OPTN final rule. If the Board of Directors approves the proposal with the new framework, plans for implementation begin.
- Board briefing paper – expected December 2021
Implementation of the policy for lung allocation is projected to take approximately 12+ months due to the range of changes, required education to the community, and expected impact.
- Policy notice – expected 2022