Master Kansas Supreme Court recognized a physician's duty to disclose material risks but measured disclosure by a professional standard established through expert testimony. with this comprehensive case brief.
Natanson v. Kline is a foundational informed consent case that helped define the contours of a physician's duty to disclose risks of proposed treatment. Decided by the Kansas Supreme Court in 1960, it sits at a pivotal early moment in the doctrinal development between the battery-based view of unconsented-to medical touchings and the negligence-based paradigm that assesses whether a physician acted reasonably in disclosing risks. Natanson adopts a professional standard—what a reasonable medical practitioner would disclose in the same or similar circumstances—and requires expert testimony to inform the trier of fact on that professional norm.
The decision is significant for two reasons. First, it squarely recognizes an affirmative duty to disclose the material hazards of treatment, an idea then just emerging in American law. Second, the court anchors the scope of disclosure in medical custom as opposed to a reasonable-patient benchmark, thereby setting up a contrast with later decisions (such as Canterbury v. Spence) that pivot to a patient-centered materiality standard. For students, Natanson illuminates the policy tensions—patient autonomy versus medical judgment—that continue to shape informed consent doctrine.
Natanson v. Kline, 186 Kan. 393, 350 P.2d 1093 (1960), opinion on rehearing, 187 Kan. 186, 354 P.2d 670 (1960) (Kan. Sup. Ct.)
Rose Natanson underwent a radical mastectomy for breast cancer and was referred for postoperative deep x‑ray therapy using cobalt‑60, then a comparatively new and potent modality. Dr. Kline, a radiologist, supervised the course of cobalt therapy at a hospital facility. Following the treatments, Natanson suffered severe radiation burns and necrosis of tissue in the chest wall, necessitating extensive medical care, including skin grafting and prolonged hospitalization. Natanson sued Dr. Kline (and others) alleging two theories: (1) negligent administration and dosage of radiation, and (2) failure to disclose material risks inherent in cobalt therapy—particularly the risk of severe radiation burns—thereby rendering her consent uninformed. At trial, the evidence on negligent administration was contested, and on the informed‑consent claim Natanson did not present expert testimony establishing what a reasonably prudent radiologist in the same or similar circumstances would have disclosed at the time. The jury returned a verdict for Dr. Kline. On appeal, the Kansas Supreme Court addressed the nature and scope of a physician's duty to disclose and what proof is required to establish a breach.
What is the scope of a physician's legal duty to disclose risks of a proposed medical treatment to obtain a patient's informed consent, and must the plaintiff offer expert testimony to establish the standard and breach of that duty?
A physician has a duty to make a reasonable disclosure to the patient of the nature of the ailment, the nature and probable risks of the proposed treatment, and, where appropriate, feasible alternatives, sufficient to enable the patient to make an intelligent decision. The scope of this duty is measured by the professional standard—what a reasonable medical practitioner in the same or similar circumstances would disclose—not by an absolute or lay standard. Except in the rare case where the need for disclosure is within the common knowledge of laypersons, the plaintiff must present expert medical testimony to establish the standard of disclosure and any deviation from it. Recognized exceptions include emergencies, incapacity, or circumstances in which disclosure would, in the physician's sound medical judgment, pose a serious threat to the patient's well‑being (therapeutic privilege).
The court recognized a physician's duty to make reasonable disclosure of risks but held that the extent of disclosure is governed by the professional standard and generally must be proven by expert testimony. Because the plaintiff failed to offer expert evidence establishing the applicable standard of disclosure and breach, the verdict for the physician was sustained.
The court began by grounding the disclosure duty in principles of bodily autonomy: a competent adult has the right to decide what is done to her body, and meaningful consent requires disclosure of material risks. However, the court declined to impose an inflexible or absolute disclosure rule, emphasizing that medical practice involves complex judgments about patient comprehension, the probabilistic nature of risks, the novelty or hazards of treatments, and the potential for information itself to cause harm or deter beneficial therapy. A purely lay-driven disclosure metric would invite juries to substitute their views for professional judgment without the necessary medical context. Accordingly, the court located the measure of disclosure in the customary practices of reasonably prudent physicians under like circumstances, echoing contemporaneous authorities such as Salgo. This tether to professional norms respects the clinician's expertise while still demanding reasonable transparency. Because those norms are not within ordinary lay knowledge and vary with factors such as the patient's condition, the seriousness and likelihood of risks, the alternatives, and the state of medical science, expert testimony is needed to establish what a reasonable physician would have disclosed and whether the defendant deviated from that standard. The court also acknowledged limited exceptions—emergencies, incapacity, and therapeutic privilege—where full disclosure may be impracticable or counter-therapeutic. Applying these principles, the court concluded that while cobalt therapy carried known hazards, the plaintiff did not supply expert evidence defining the profession's disclosure standard for such therapy or demonstrating a breach by Dr. Kline. Absent such proof, the informed‑consent claim could not go to the jury on a negligence theory. The court therefore let stand the defense verdict, while clarifying the applicable legal framework for future cases.
Natanson is an early and influential articulation of informed consent in negligence, adopting a professional standard for disclosure and requiring expert testimony to prove it. It frames the classic tension between physician‑centered custom and patient‑centered autonomy, paving the way for later doctrinal divergence (e.g., Canterbury's reasonable‑patient standard). It remains a principal case for understanding expert proof in medical malpractice and the scope/limits of the therapeutic privilege.
Natanson measures the adequacy of disclosure by what a reasonably prudent physician in the same or similar circumstances would disclose, typically proven through expert testimony about professional custom. Canterbury instead asks what a reasonable patient would deem material to the decision, focusing on the significance of risks to patient choice rather than medical custom. The former is physician‑centric; the latter is autonomy‑centric.
Because the scope and content of medically appropriate disclosure—especially for complex or evolving treatments like cobalt therapy—are not within common lay knowledge. Expert testimony informs the jury about professional norms, probabilities, materiality of risks within the profession, and how circumstances affect disclosure. Without it, a jury would be speculating about medical standards.
Natanson frames failure to make reasonable disclosure as negligence, not battery. Battery traditionally addresses unauthorized or substantially different procedures without consent at all. In Natanson, the procedure was consented to in kind; the alleged wrong was inadequate disclosure of risks, which the court analyzed under a negligence standard requiring proof of duty, breach (measured by professional norms), causation, and damages.
The court acknowledged limited exceptions: emergencies where treatment is immediately necessary and consent cannot be obtained; incapacity; and therapeutic privilege, where disclosure in the physician's sound medical judgment would pose a serious threat to the patient's well‑being (e.g., causing shock or harm). Even then, the privilege is narrow and subject to scrutiny.
Plaintiffs must secure qualified medical experts to testify about what a reasonably prudent physician would have disclosed under similar circumstances, identify specific material risks and alternatives that should have been disclosed, and connect the nondisclosure causally to the patient's decision and ensuing injury. Without expert proof of the disclosure standard and breach, the claim typically fails.
It informed the court's recognition that risks existed and disclosure was important, but it did not alter the evidentiary requirement. Even for novel or hazardous treatments, the plaintiff still had to establish, through expert testimony, what the professional disclosure standard required at the time and that Dr. Kline deviated from it.
Natanson v. Kline crystallizes the negligence-based approach to informed consent under a professional disclosure standard. While affirming patients' rights to information necessary for intelligent decision‑making, the court channels the content of that duty through medical custom, generally requiring expert testimony to delineate and prove breach of the duty.
For law students, Natanson provides the doctrinal counterpoint to Canterbury: it shows how courts balance respect for medical expertise with patient autonomy and why evidentiary structures—especially expert proof—so often determine outcomes in medical malpractice litigation. Understanding Natanson equips students to analyze informed-consent claims across jurisdictions that still adhere to, or have evolved from, the professional standard.
Need to cite this case?
Generate a perfectly formatted Bluebook citation in seconds.
Use our Bluebook Citation Generator →