Organ Donation Defaults: What Really Drives Outcomes

TLDR: Opt‑out vs. opt‑in by itself does not reliably increase transplantation. Outcomes depend on infrastructure, coordinator networks, governance, and family conversations; not the checkbox.

Evidence summary

  • Cross‑country analyses show no reliable increases in total transplantation from opt‑out systems alone.
  • Some countries saw increases post‑law; others saw no change or declines absent system investments.
  • High‑performers (e.g., Spain) succeed by building a national coordinator network, training staff to identify donors and conduct family conversations, and optimizing processes (e.g., DCD, expanded criteria) and data/reporting.

See Evidence Ledger:

BS-0004

Why “defaults did it” is misleading

  • Defaults change governance (who is presumed a donor) but don’t create donor identification, family consent, ICU capacity, or surgical throughput.
  • “Hard” opt‑out still requires family conversations in practice; bedside barriers remain.
  • Successful systems implement multi‑level changes: public education, clinician training, coordinator staffing, registries, logistics, and data transparency.

Guidance for policy and practice

  • If changing legal defaults, plan the system build: coordinators, training, ICU pathways, family engagement scripts, logistics, and verified reporting.
  • Report outcomes transparently (per‑million‑population rates, denominators/windows) and attribute gains to specific system components.

See also: Why Nudges Fail, Nudge Limitations.