The right to refuse treatment: an application of the economic principles of decision-making under uncertainty.
When courts do not defer to professional judgment, alternative ways must be used to make treatment decisions for persons who are deemed incompetent. Rather than impose the preferences of society on the mentally ill individual, courts have favored alternative procedures. The two most common approaches are substituted judgment and best interests. In using both the substituted judgment standard and the best interest standard the guardian of a patient who is judged incompetent to make a treatment decision tries to make the decision the patient would have made, had he been competent. The guardian must consider the individual's attitude toward risk in making this assessment. Substituted judgment can be used when clear and convincing evidence of the patient's preferences exists. The evidence would come from a study of the patient's expressed attitudes towards medical treatment and behavior before he or she became incompetent. This approach is effective only if the patient has revealed his or her preferences toward relevant medical treatment in the past. The best interest standard is used when no clear and convincing evidence of the patient's treatment preferences exists. The treatment decisions of competent patients whose characteristics are similar to the incompetent patient's, and who have faced a similar situation, can be used as a proxy for the decision the incompetent patient would have made. Using the choice function of similar people may make it possible to develop a reasonably objective basis for determining what course of action is in the patient's best interest.