There are never enough organs, intensive care beds or doctors' hours for everyone who needs them. Someone must decide who gets what. Refusing to decide is also a decision, usually in favor of whoever is first, richest or best connected. Bioethics tries to make these choices fair and open.

Triage

The word triage comes from the French for sorting. Dominique-Jean Larrey, chief surgeon of Napoleon's armies, is often credited with the practice of treating wounded soldiers by the severity of their wounds rather than their rank. Modern mass-casualty triage sorts patients into groups: those who will survive without immediate care can wait, those who will die whatever is done receive comfort, and those for whom quick treatment makes the difference go first. Triage aims to save the most lives, which means some people who would get full care on a normal day do not get it.

The Seattle committee

In 1962 the Seattle Artificial Kidney Center had only a few dialysis machines for many patients with kidney failure. An anonymous committee of seven local citizens chose who would be treated. It judged candidates partly on their social worth, considering such things as income, church membership, number of children and potential contribution to society. A magazine exposé made the committee notorious. Critics said it rewarded conventional middle-class lives and that worth to society is the wrong question in medicine. The controversy helped persuade Congress in 1972 to extend Medicare to cover dialysis for nearly everyone with kidney failure.

Organs

In the United States, the National Organ Transplant Act of 1984 banned buying and selling human organs, and a national network runs the waiting list. Allocation rules weigh medical urgency, time on the list, how well tissue matches and how far the organ must travel. Each factor reflects a value: helping the sickest, fairness to those who have waited, and making the transplant succeed.

Two debates remain lively. One is whether to pay donors. Iran has allowed regulated paid kidney donation since 1988 and reports short waiting lists, while critics say such markets exploit the poor and crowd out generosity. The other is how to raise donation rates. Many countries have switched to opt-out systems in which people are presumed donors unless they object. Spain has one of the world's highest donation rates, but experts usually credit Spain's success to its national system of transplant coordinators rather than its opt-out law, which existed for years before rates rose.

Counting benefit

Health systems that ration openly need a measure of benefit. The most common is the quality-adjusted life year, or QALY. A QALY combines length of life with its quality: a year in full health counts as one, a year in poor health as less. England's National Institute for Health and Care Excellence has long judged new treatments partly by their cost per QALY. Defenders say this makes trade-offs visible and treats everyone's health by the same rule. Disability advocates object that QALYs can rate a year lived with a disability as worth less, so treatments for disabled people may seem poorer value. US law limits the use of QALYs in Medicare decisions for this reason.

Competing principles

Philosophers have proposed several rules, each with strengths. A lottery, or first come first served, treats each person's claim as equal but ignores need and benefit. Sickest first honors urgency but can waste resources on those least likely to recover. Maximizing benefit saves the most life years but tends to favor the young and healthy. The fair innings argument, defended by the economist Alan Williams, gives priority to those who have had fewer years of life. Most real systems combine several of these principles.

The COVID-19 pandemic tested all of this. Some hospitals in Italy and elsewhere faced too few ventilators in 2020. Some US states' emergency guidelines would have ranked patients with certain disabilities lower, and several were revised after civil rights complaints. The episode showed why rationing rules should be written in calm times, in public, with the people they affect.

Worked example: one liver, two patients

A donated liver becomes available. Patient A is fifty-five, very sick and expected to die within weeks without a transplant; his liver failure followed years of heavy drinking, though he has been sober for a year. Patient B is thirty, less ill but declining, with a rare inherited disease. A strict sickest-first rule favors A. A rule that maximizes expected life years may favor B. A fair innings view also leans to B. Some people would add that A caused his illness, but many ethicists warn against judging blame: drinking has many causes, including genes and circumstance, and few other patients are asked whether they smoked or skipped exercise. Most transplant systems use medical urgency and likelihood of success rather than moral judgments, and require a period of sobriety for clinical, not punitive, reasons. Writing down which principle decides, and why, is what keeps such choices from being arbitrary.