Heterogeneous donor circles for fair liver transplant allocation.

Area of Science:

• Organ transplantation research
• Health services research
• Operations research

Background:

• Geographical disparities in organ access exist in the U.S.
• Current organ allocation systems face challenges in ensuring equitable distribution.
• Organ supply to patient demand (s/d) ratios vary significantly across transplant centers.

Purpose of the Study:

• To develop a novel organ allocation model for increasing geographical equity in liver transplantation access.
• To address legal challenges associated with organ distribution frameworks.
• To optimize organ supply allocation to maximize minimum s/d ratios.

Main Methods:

• Developed a nonlinear integer programming model.
• Formulated the problem as a set-partitioning problem.
• Designed a heterogeneous donor circle policy optimizing donation region radii.

Main Results:

• The heterogeneous donor circle policy significantly improved the worst s/d ratio and reduced the range between maximum and minimum s/d ratios.
• Under the new policy (max 500 NM radius), s/d ratios ranged from 0.55 to 0.60, closely matching the national average of 0.5983.
• This contrasts with a fixed 500 NM radius policy, where s/d ratios ranged from 0.37 to 0.84.

Conclusions:

• The heterogeneous donor circle policy offers a more equitable organ supply and demand match compared to existing policies.
• This model has substantial potential to improve the landscape of liver transplantation in the U.S.
• Optimizing donation region radii can effectively mitigate geographical disparities in organ access.