Feedback & Responses

TSANZ thanks everyone who took the time to submit their feedback on the new kidney allocation algorithm as part of the public consultation window in April/May 2025.

A variety of issues were raised and are addressed below.

Is there a role for donor versus recipient age-matching in the new system?

The proposed new algorithm uses “prognosis matching” to minimise differences in the expected lifespan of the donor kidney and the recipient. Prognosis matching points are calculated based on the difference between the Kidney Donor Profile Index (KDPI) score and the Expected Post Transplant Survival (EPTS) score of the recipient, with higher points awarded for like-for-like matches. The largest prognosis points scores go to low-KDPI to low-KDPI matches and high-KDPI to high-EPTS matches.

The KDPI and EPTS scores are largely driven by age; prognosis matching, therefore, is very similar to age matching. However, prognosis matching has the advantage of also taking into account other relevant factors that impact on kidney quality, such as history of diabetes, history of hypertension, kidney function, stroke as cause of death and circulatory versus brain death.

Simulations of the new system indicate that prognosis matching would be improved compared to the status quo. Age matching would also be improved: in particular, there are fewer instances of young donor kidneys going to older recipients in the simulation.

The options of direct age matching or penalties for very wide disparities in donor and recipient age were considered and tested. These options, however, did not deliver better system outcomes compared to, or in addition to, prognosis matching.

How does the new algorithm address the needs of paediatric patients?

The goals of the new algorithm with respect to children and young people are to (i) reduce the risk of sensitisation against future transplants (ii) minimise time on dialysis and (iii) match young recipients with kidneys with a long expected lifespan.

Instead of a simple waiting time bonus, the new algorithm gives priority to paediatric patients and young people in proportion to the quality of the immunological match with the donor. The quality of the immunological match is reflected by an HLA match score. Age-based waiting is then applied to HLA match scores, to give particular emphasis to good HLA matches for young people. Therefore, for a given paediatric candidate, when a donor arises that is a good HLA match for them personally (taking into account that some patients are harder to match than others) this match will be given a large points bonus.

Put another way, instead of simply being “first in line” for the next kidney offer, paediatric patients will get very high priority for any kidneys that are a good immunological match for them personally. The age-based weighting applied to HLA matching scores is shown below. Weighting declines gradually until age 18, then more rapidly thereafter.

Simulations indicate that the new algorithm will result in paediatric patients getting better quality, better matched, offers. That is, it is predicted that the new algorithm will result in paediatric patients being transplanted with kidneys that are likely to last longer and cause less sensitisation.

What is the reasoning for giving priority to prior living donors?

Under the new algorithm, prior living donors would get 10 bonus points. Ten points is equivalent to 10 years of waiting time in terms of its impact on a person’s continuous points score. This value was chosen on the basis that (a) highly sensitised, urgent, and excellent matches for young people would still automatically out-rank prior living donors and therefore would not be impacted by this rule and (b) it would allow prior living donors to decline bad matches while getting offers frequently enough to enable them to be transplanted reasonably quickly.

A consumer consultation on the proposed new algorithm was undertaken as part of this project and engaged 23 consumers (transplant recipients and currently waitlisted patients) in a series of small group sessions. The participants in the consumer consultation expressed strong, unanimous support for giving prior living donors priority in allocation.

If, after being appropriately screened for living donation, a living donor goes on to develop kidney failure, then priority in allocation reflects the principle of reciprocity. The donor has contributed to meeting the needs of the community and priority on the waiting list mitigates the physical harms they have voluntarily incurred through this act. This is consistent with consumer views: the consumers that were consulted for this project stated that priority for prior living donors is something they would consider fair and just. Consumers frequently referred to living donation as an altruistic act and a gift; importantly however, the purpose of a priority bonus for prior living donors is not a reward for an altruistic act – it is intended as fair and just response to harms incurred through the act of living donation.

Could additional priority be considered for people living in remote areas who have to travel long distances for dialysis?

An underlying principle of the Australian kidney allocation system is that waitlisted patients, regardless of gender, ethnicity or location of residence, have an equal right to transplantation. Where the system gives additional priority, this is to address biological barriers that make it more difficult for some people to find a compatible kidney or in specific urgent or otherwise exceptional cases. Children and young people are also given priority over older recipients for well-matched kidneys; this is also largely for biological/clinical reasons.

The many challenges of having to travel long distances for dialysis are acknowledged. Giving priority to certain waitlisted candidates based on location of residence so that they get transplanted faster than other candidates would not, however, be consistent with equity goals. There are also some practical limitations to consider. In particular, many people move in order to access dialysis, making it difficult to accurately and fairly determine who would qualify for a theoretical remoteness bonus.

Poor access to dialysis facilities in remote parts of Australia is a real issue, but not necessarily one that is best addressed via the kidney allocation algorithm.

When will HLA matching for antibody epitopes be introduced?

The potential for epitope matching was discussed by the Working Group and with the heads of Australian Tissue Typing labs during stakeholder consultations. The expert view was that scientific and technical limitations currently preclude the incorporation of eplet matching into the allocation algorithm. Specifically:

Real-time donor typing is not universally at a sufficiently high resolution to support eplet matching
Eplets are not yet sufficiently defined – i.e. we do not yet have a complete picture of the significance of all mismatches and this knowledge base would need to be more advanced before we could design an approach that would yield consistent outcomes.

However, it is anticipated that this situation will change in future. The proposed approach to how we assign points for HLA matching in the new algorithm – based on the relative quality of a given match versus what the candidate can expect from the donor pool – can be readily adapted to a future matching paradigm based on eplets instead of antigens.

Will the new algorithm be monitored for unintended consequences?

Monitoring and evaluation of the new allocation algorithm is essential, as is system transparency. A monitoring and evaluation plan has been prepared that includes recommendations for regular data monitoring and formal reporting at 12 and 24 months post-implementation. These reports will include detailed data on system outcomes and an assessment of how well the new system is meeting its stated objectives. It will also describe plans to address any unintended consequences or aspects of the algorithm that are not meeting benchmarks. These reports will be accessible by all stakeholders (including patients and families).