Redesigning deceased donor kidney transplant allocation in Australia

Abstract

Kidney transplantation is a life changing event for a person living with end stage kidney disease and the allocation of deceased donor kidneys can have profound impacts on who has access to this treatment, the benefit that is derived from the gift of donation and the long term outcomes for the individual receiving the organ. The system that determines the allocation of deceased donor kidneys comprises a number of interconnected processes and must address a range of competing priorities. This thesis presents a series of related studies that provide evidence on the current state of deceased donor kidney allocation and demonstrate the feasibility and effectiveness of a novel framework for redesigning organ allocation protocols in Australia.

In order to better understand the context in which allocation occurs, Chapters 3 and 4 address key knowledge gaps in the Australian deceased donor kidney transplant system, reporting on the predictors of access to kidney transplant waitlisting in Australia, highlighting the disadvantage experienced by key populations, and exploring the causes of a recent increase in kidney non-utilisation.

Chapter 5, 6 and 7 analyse the impacts of previous changes to the allocation system, assessing their effectiveness, unintended consequences and highlighting key areas in which further policy intervention is required. The study reported in chapter 5 demonstrates that the reporting of the Kidney Donor Performance Index (KDPI) with organ offers in Australia was associated with changes in acceptance behaviour but not an increase in non-utilisation and provide insights into how donor risk indices might be incorporated into future allocating algorithms. Analysis of the impact of the introduction of calculated panel reactive antibody (cPRA) to define sensitization for kidney transplant candidates, described in chapter 6, reveals the scale of disadvantage experienced by very highly sensitized patients and the ineffectiveness of the current allocation system in addressing this, adding urgency to the call for policy change to address this.

Further evidence to support change is reported in chapter 7, in an analysis of the effectiveness of paediatric bonuses in the Australian deceased donor kidney allocation system. This shows that whilst paediatric candidates are achieving rapid access to high quality organs, under current rules children are not receiving kidneys with optimal immunological matching. Chapter 8 explores the association between HLA epitope based matching and clinical outcomes in the paediatric population to investigate whether this may have potential as a novel approach to reducing immunological risk through optimised allocation.

Addressing the broader question of what the allocation system should be trying to achieve, results of a best worse scaling choice experiment presented in Chapter 9 show key differences in the principles prioritized by healthcare professionals when compared to the general community.

The final chapter of the thesis reports the development, validation and implementation of a platform to simulate deceased donor kidney allocation in Australia. In working closely with the national Renal Transplant Allocation Committee (RTAC), this study not only provided proof of concept for the value of simulation in organ allocation policy development in Australia but produced direct and tangible improvements in the policy that will be implemented.

In taking a holistic approach to the process of redesigning deceased donor kidney allocation this work reports several novel findings that have had a direct impact on policy development and lays the foundations for an ongoing framework of evidence-based design for deceased donor kidney allocation in Australia.