 A persuasive criterion of rationality in rationing is efficiency: since supply is not infinite we must ensure that every allocated resource is used to achieve the maximum benefit it can provide. While in some domains the nature of a “benefit” is controversial, here it is obvious: health resources produce health benefits, either incremental improvements in health or the prevention of worsening health and premature death. Understanding death (or premature death) as the worst health outcome, life-saving or life-prolonging is (usually) a clear health benefit. But so is improving bodily functioning, mitigating or ameliorating functional problems or preventing functional decline. Although death is not preventable, disease, injuries, and other challenges to an individual’s health can either be prevented or their impact lessened, either indefinitely or for some period of time. Health outcomes, in short, are either quantitative (number of years lost to a health challenge) or qualitative (extent of functioning lost).