Others who oppose rationing health care on the basis of age argue that a mere consideration of benefits and costs fails to give due weight to other more important moral considerations, such as justice and rights.
Justice, they argue, requires that people be treated similarly unless there are morally relevant reasons for treating them differently.
In determining who should or should not receive health care, it is relevant to consider a person's need for health care, the likelihood of recovery, or the likelihood of improving a person's quality of life.
Age, however, reveals little about a person's medical need or prognosis, and should no more influence the distribution of health care than race or sex.
It is the medical liabilities we often associate with old age, not age itself, that count as relevant reasons for treating people differently.
If our aim is to use costly resources more effectively, then we ought to deny treatment to all patients whose prognosis indicates a short life span, chronic illness, or little likely improvement in the quality of life, rather than denying treatment simply on the basis of age.
http://www.scu.edu/ethics/publications/iie/v3n3/age.html