Marginal capacity: the dilemmas faced in assessment and declaration.

Ontario is adopting informed-consent legislation that reflects increasing emphasis on patient autonomy and self-determination. Capacity assessment and declaration by physicians and other health care professionals are pivotal under the new legislation. While grossly capable or incapable patients provide few management difficulties, marginally capable patients provide a challenge for physicians who must assess capacity, and decisions concerning them emphasize the ethical dilemma involved in any declaration of incapacity. Our 1994 Logie Medical Ethics Essay first-prize winner, Vincent Ho, examines the issues that clinicians must consider when assessing marginally capable patients.