Missouri Department of Health Cruzan v. Director

The right to refuse medical treatment is a constitutionally protected liberty interest. Unlike assisted suicide, it lacks the potential element of abuse because patients can establish future previsions to discontinue life support systems such as a living will. Additionally, if the patient is unable to articulate his views or has not signed a living will, family members can express the patient's desire to discontinue life support. Family members can recall conversations during which the patient expressed a desire not to continue with life support. Furthermore, if there is a disagreement among family members about the patient's desire it is easier to determine which side of the family is correctly expressing the patient's wishes.

Yet some argue there is little difference between ending life support and intervening to promote death. Others assert that a patient's physician can more accurately reflect and act on the patient's desire without the emotional entanglements that could hinder the family's judgement. Just as the family member can discuss the patients' wishes, the doctor based on his relationship with the patient prior to the illness, would have the same information.