387 Mass. 152, 439 N.E.2d 240 (Mass. 1982)
Harnish v. Children's Hospital Medical Center is the Massachusetts Supreme Judicial Court's landmark decision aligning the Commonwealth with the modern, patient-centered doctrine of informed consent.
Does a physician's duty to disclose information for informed consent in Massachusetts depend on the professional standard of disclosure (what physicians customarily reveal) or on a patient-oriented standard of materiality (what a reasonable patient would consider important), and how should causation be assessed in such claims?
In Massachusetts, the duty to disclose in informed consent cases is measured by what information a reasonable patient in the physician's position would consider material to making a decision about treatment. A risk (or alternative) is material if a reasonable patient, in what the physician knows or should know to be the patient's position, would be likely to attach significance to it in deciding whether to undergo the proposed therapy. The physician must disclose material risks, benefits, and reasonable alternatives, subject to recognized exceptions (e.g., emergencies, incompetence, and a narrow therapeutic privilege). To prevail, the plaintiff must prove: (1) the physician failed to disclose a material risk or alternative; (2) the undisclosed risk materialized and caused injury; and (3) causation under an objective standard—i.e., that a reasonable person in the patient's position would have declined or chosen differently if properly informed. Expert testimony is generally required to establish the existence, nature, and probability of medical risks and alternatives, but not to establish the legal standard or the materiality determination, which is for the factfinder.
The Supreme Judicial Court adopted the patient-oriented, materiality standard for informed consent and an objective reasonable-patient test for causation. Because the trial court instructed the jury under a physician-centered professional disclosure standard, the judgment for the defendants was reversed and the case remanded for a new trial under the proper legal framework.
Harnish is the leading Massachusetts case on informed consent. It cements the patient-oriented, materiality standard for disclosure; clarifies that the action sounds in negligence; adopts an objective reasonable-patient test for causation; and explains the role of expert testimony. Doctrinally, it aligns Massachusetts with modern tort theory, prioritizing patient autonomy over professional custom. Practically, it provides a clear checklist for evaluating informed consent claims and informs model jury instructions across the state.