A harm-threshold model for ethical organ allocation.

Area of Science:

• Organ transplantation ethics
• Medical decision-making algorithms
• Public health policy

Background:

• Scarce donor organ allocation requires balancing improved overall outcomes with protecting patients at high near-term risk.
• Urgency-focused systems like MELD save lives but may reduce total post-transplant survival.
• Unconstrained utility maximization risks bypassing the sickest patients.

Purpose of the Study:

• To introduce Harm-Threshold Utilitarianism (HTU), a novel ethical framework for organ allocation.
• To maximize expected post-transplant benefit while incorporating safeguards against epistemic uncertainty and catastrophic harm.
• To compare HTU with MELD-based selection using simulated liver transplant data.

Main Methods:

• Developed Harm-Threshold Utilitarianism (HTU) with epistemic and catastrophic harm thresholds.
• Simulated liver organ offer pools using de-identified U.S. liver transplant registry data.
• Compared HTU with MELD-based selection, analyzing Kaplan-Meier curves and 5-year restricted mean survival time (RMST).

Main Results:

• HTU reorders candidates transparently, aligning with broad priorities.
• HTU-selected recipients showed improved post-transplant survival, with a mean RMST increase of ~0.25 years per transplant.
• Sensitivity analyses demonstrated an urgency-efficiency frontier based on the catastrophic harm threshold.

Conclusions:

• HTU operationalizes a tunable, ethically explicit trade-off between benefit and protection for the worst-off.
• HTU offers measurable efficiency gains without sacrificing fairness by encoding precaution and a harm floor.
• HTU reframes organ allocation policy choices as transparent, reviewable parameters.