What is the current test for respecting a patient's right to refuse life-sustaining treatment even when the patient becomes incompetent?

Actually the cited cases dealt with an extension of the rule, requiring the doctors and hospitals to respect the right even when the patient becomes incompetent if, while competent, the patient had clearly stated a desire to decline life-sustaining treatment under specified circumstances. In each case we held that this was a matter of personal choice, and that the patient's wishes should be honored if there was clear and convincing evidence that the patient had made a firm resolve to decline life-sustaining treatment. Where there was such proof, we ordered that life-sustaining measures be discontinued (Matter of Eichner v. Dillon, supra ); but where the patient's statements were equivocal and did not clearly show a firm resolve to make such a choice under the circumstances (Matter of Westchester County Med. Center [O'Connor], supra ) or where the patient was incapable ever of making such a choice because of retardation (Matter of Storar, supra ) we ordered that medical care continue.