In Nickell v. Gonzalez (1985), 17 Ohio St.3d 136, the Ohio Supreme Court established the tort of “lack of informed consent”:

“The tort of lack of informed consent is established when:  (a) The physician fails to disclose to the patient and discuss the material risks and dangers inherently and potentially involved with respect to the proposed therapy, if any;  (b) the unrevealed risks and dangers which should have been disclosed actually materialize and are the proximate cause of injury to the patient; and (c) a reasonable person in the position of the patient would have decided against the therapy had the material risks and dangers inherent and incidental to treatment been disclosed to him or her prior to the therapy.”

Ohio also has a statute that governs informed consent:  RC 2317.54.