Massachusetts Medical Society
The right to refuse treatment is firmly recognized in U.S. law. Competent persons have the legal right to refuse treatment, even life-sustaining treatment, and incompetent patients can also refuse treatment through an advance directive, by naming a health care agent to make decisions for them or by having a person who knows their wishes express them.
George J. Annas,
Forcible Medication for Courtroom Competence: The Case of Charles Sell
New England Journal of Medicine
Available at: https://scholarship.law.bu.edu/faculty_scholarship/1282