A review of the history of medical decision making reveals a shift in the way patients and clinicians make decisions. In the past, medical decision-making authority generally rested in the hands of clinicians caring for the patient; typically, patients completely accepted the recommendations of their physicians. In the United States, this paternalistic style of medical decision making lost favor in the second half of the twentieth century, propelled by court decisions in malpractice cases and coinciding with the ascendency of civil and individual rights in many aspects of American life (e.g., the release of warehoused mental health patients, the abolition of legal segregation, and the lowering of the voting age). Most patients, clinicians, and society now recognize the importance of patient or surrogate involvement in the medical decision-making process. The idea that patients have a right to be informed about their health information and have a right to accept or reject offered or recommended medical interventions has emerged as the guiding ethical and legal principle in our medical decision making. This shift in the locus of control over decisions respects the autonomy of the patient or the authority of the patient’s legally authorized representative. Clinicians must now carefully balance promoting what they believe represents the best interests of the patient with respecting the patient’s or surrogate’s views about how to proceed. This model of medical decision making has come to be known as shared decision making to distinguish the process from a solely professional or patient-centered process [1, 2].

Our understanding of informed consent evolved as a result of the changes in the medical decision-making process and also in part as a result of several landmark legal cases. One of the earliest cases highlighting the concept of informed consent, Schloendorff v. The Society NY Hospital, was decided in 1914. In the case, Ms. Schloendorff presented with abdominal pain and consented to an exam under anesthesia to determine if a diagnosed tumor was malignant. However, she did not agree to surgical removal of the tumor. During the procedure, her surgeons found a large malignant abdominal mass. They proceeded to resect the mass against her wishes rather than put her through another surgery. Ms. Schloendorff sued the hospital and the court ruled in her favor stating that her physicians had committed medical battery in proceeding with a surgery for which they had no consent. The court’s opinion included, “every human being of adult years and sound mind had a right to determine what shall be done with his body; and a surgeon who performs an operation without his patient’s consent commits an assault, for which he is liable in damages. This is true except in cases of emergency, where the patient is unconscious, and where it is necessary to operate before consent can be obtained” [3]. While the surgeons acted based on what they believed was in the best interests of the patient, the concept of unilateral decision making by physicians was starting to lose favor. Respect for patient autonomy had begun to emerge as an equally important component of medical decision making. Physicians had to promote the best interests of the patient, yet ultimately defer to what the patient believed represented his or her best interests.

This landmark ruling brought the importance of consent to the forefront of medical ethics discussions for years to come. Schloendorff gave rise to the notion of simple consent, making the provision of medical treatment contingent on specific consent from the patient or surrogate. However, this 1914 decision did not address the quantity and quality of the information physicians should share with patients. Perhaps clinicians also need to make sure patients understand the indications, risks, benefits, and alternatives to the recommended treatment. In 1957, the case of Salgo v. Leland Stanford Jr. University Board of Trustees clarified these matters under the law. Mr. Salgo presented with aortic thrombosis requiring aortography for diagnosis. His post-procedure course was complicated by permanent paralysis. Later investigation found that the intravenous contrast used in the case had not been used often enough to constitute routine practice. Salgo’s physicians knew of the risks associated with the procedure, but did not provide that information to their patient. The court ruled that the “physician violates his duty to his patient if he withholds any facts which are necessary to form the basis of an intelligent consent by the patient to the proposed treatment” [4]. Our modern understanding of fully informed consent finds its roots in this case. Simply obtaining voluntary consent from a patient no longer sufficed; physicians had to ensure that patients received the information the patient needed to make a fully informed decision.

The legal discussion turned to how to define adequate disclosure in the informed consent process. Two different types of disclosure emerged in arguments before courts: the professional practice versus the reasonable person standard. The professional practice standard holds that adequate disclosure is determined by the customary physician behavior in a particular professional peer group. From this perspective, the physician should tell the patient what he or she believes another reasonable and experienced physician in the same community would disclose in similar circumstances. A variation on this approach involves disclosure of the amount of information a well-informed physician, current on relevant medical information, judges the patient needs in order to weigh the risks and benefits of the care options. By contrast, the reasonable person standard states that the physician should disclose all information that a reasonable lay person would want to know to make an informed decision. This disclosure standard seeks to shift control from the physician to the patient and family. While courts have largely abandoned the professional practice standard in favor of a patient-centered standard, no universally accepted definition of a reasonable patient exists. Moreover, recent thinking in medical ethics and legal precedent go beyond simple disclosure to an assessment by the clinician of the adequacy of the patient’s or surrogate’s understanding of the risks, benefits, and alternatives of available interventions (or nonintervention). Discovery of an inadequate or flawed appreciation of the facts should then trigger additional attempts to educate the decision maker or further inquiry into the patient’s or surrogate’s decisional capacity. In other words, no valid consent exists if it turns out the decision maker does not have adequate information, does not understand the information, or lacks the ability to make a decision appropriate to the circumstances. As part of the informed consent process, clinicians best serve patients and protect themselves by determining and meeting the unique informational and decision-making needs and preferences of particular patients and families [5].