One Size Doesn't Fit All: A Review of International Deceased Donor Kidney Allocation Algorithms

Deceased donor kidney allocation algorithms seek to balance equity, need, and utility within regional healthcare constraints. Although many countries have formal systems, comparative analyses of their structure, context, and evolution remain scarce.

We conducted a targeted review of 21 allocation algorithms across five continents, identified through literature searches, transplant organization websites, and policy documents. Core components analyzed included wait time, age, immunologic risk, medical urgency, and donor-recipient matching. Three case studies - the United States, Canada, and Eurotransplant - illustrate how governance and sociopolitical factors shape design and reform.

All algorithms incorporated wait time and age, with variable definitions and weighting. Most addressed panel reactive antibody, pediatric priority, and medical urgency, but thresholds and implementation differed. Donor-recipient matching strategies included HLA mismatch scoring, ABO compatibility, and longevity matching via donor age, Kidney Donor Profile Index, or Expected Post-Transplant Survival. The US, Canadian, and Eurotransplant case studies highlighted contrasting centralized versus provincial governance and their influence on reform.

Grounded in shared ethical principles, kidney allocation algorithms differ in how these are operationalized. This global comparison identifies opportunities to enhance transparency and equity, offering practical guidance for jurisdictions developing or refining allocation systems to align with ethical values and local realities.