Informed consent (IC) is a medicolegal term describing the documented conversation between a patient and their physician wherein the physician discloses all relevant and necessary information to a patient who is competent to make an informed and voluntary decision regarding their care. Competency, disclosure, and voluntariness are the key elements upon which IC is based. The patient’s well-being and autonomy are the 2 key fundamental moral values that are preserved by IC. Medical care decisions requiring IC range from the choice to undergo a defined medical or surgical treatment to participation in a research study. The IC represents shared decision-making between the patient and their caregiver and is thus mandatory for both clinical care and enrollment in research studies. Informed consent is usually documented in a signed written form.
Informed consent (ICICInhaled Anesthetics) is a medicolegal term describing the conversation between patient and physician wherein the physician provides all relevant and necessary information for a patient to make an informed and free decision regarding their care.
Characteristics of informed consent
Fits firmly with the foundation of ethical medical practice, consisting of the basic ethical principles of autonomyAutonomyRespect for the patient’s right to self-rule.Medical Ethics: Basic Principles, beneficenceBeneficenceThe state or quality of being kind, charitable, or beneficial. The ethical principle of beneficence requires producing net benefit over harm.Medical Ethics: Basic Principles, nonmaleficenceNonmaleficenceNot acting with the intention to do harm.Medical Ethics: Basic Principles, and justiceJusticeAn interactive process whereby members of a community are concerned for the equality and rights of all.Research Ethics
The 3 basic components of ICICInhaled Anesthetics—competency, disclosure, and voluntariness—were expanded to 4 basic elements by Cordasco in 2013:
Description of the clinical problem, the proposed treatment, and alternatives, including no treatment
Discussion of the risks and benefits of the proposed treatment, with comparisons to the risks and benefits of alternatives, and discussion of medical and clinical uncertainties regarding the proposed treatment
Assessment of the patient’s understanding of the information provided by the medical provider
Solicitation of the patient’s preference and consent for treatment
Incorporates ethical and legal obligations of medical professionals to ensure that:
The patient is competent (i.e., has decision-making capacityDecision-making capacityDecision-making capacity describes a patient’s ability to make autonomous decisions regarding their care, as determined by a physician.Decision-making Capacity and Legal Competence); they have the ability to understand information relevant to a decision and to appreciate the reasonably foreseeable consequences of a decision or lack of decision.
The patient comprehends the information provided, including explanations and disclosuresDisclosuresRevealing of information, by oral or written communication.Conflict of Interest of the:
Intended intervention
Possible risks and complications
Benefits of procedures
Available alternatives, including the consequences of forgoing treatment
Represents collaborative decision-making between the clinician and the patient regarding the steps that will be followed in care. “Informed consent” is both a written form and a discussion.
In the United States, 4 judicial decisions (“landmark cases”) in the early 20th century laid the foundation for the principle of patient autonomyAutonomyRespect for the patient’s right to self-rule.Medical Ethics: Basic Principles when planning diagnostic and/or therapeutic medical procedures:
1905: Mohr v Williams: The defendant physician changed the original plan of surgery after the patient was anesthetized.
1905: Pratt v Davis: The physician performed a hysterectomy without the patient’s consent, claiming that she was not competent because of her history of epilepsyEpilepsyEpilepsy is a chronic brain disorder marked by recurrent and unprovoked seizures. These seizures can be classified as focal or generalized and idiopathic or secondary to another condition. Clinical presentation correlates to the classification of the epileptic disorder. Epilepsy.
1913: Rolater v Strain: The surgeon removed a boneBoneBone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types from the patient’s footFootThe foot is the terminal portion of the lower limb, whose primary function is to bear weight and facilitate locomotion. The foot comprises 26 bones, including the tarsal bones, metatarsal bones, and phalanges. The bones of the foot form longitudinal and transverse arches and are supported by various muscles, ligaments, and tendons.Foot: Anatomy during the incision and drainageIncision And DrainageChalazion of an infection, despite explicit instructions by the patient to not remove it.
1914: Schloendorff v Society of New York Hospital: The patient consented to exploratory surgery but stated her wish not to have a hysterectomy to remove a fibroid tumorTumorInflammation without her consent. New York Supreme Court Judge Benjamin Cardozo wrote, “Every human being of adult years and sound mind has a right to determine what shall be done with his own body; and a surgeon who performs an operation without his patient’s consent commits an assault, for which he is liable in damages.”
Other cases
1947: The Nuremberg CodeNuremberg Code10-point statement introduced as the final judgement of the tribunal at the Nuremberg trials (1947), when the atrocious experiments carried out by Nazi physicians and researchers on human test subjects in concentration camps came to light.Research Ethics, regarding Informed Consent in ResearchResearchCritical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws.Conflict of Interest Studies Involving Human Subjects:
This code was formulated by the International Military Tribunal during the investigation of Nazi war crimes at the end of World War II, in a trial of 23 physiciansPhysiciansIndividuals licensed to practice medicine.Clinician–Patient Relationship and bureaucrats charged with crimes against humanity and war crimes for medical experiments conducted on concentration campcAMPAn adenine nucleotide containing one phosphate group which is esterified to both the 3′- and 5′-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and acth.Phosphodiesterase Inhibitors inmates.
Consists of 10 basic rules for the conduct of human experiments
Represents the first explicit attempt to regulate the ethical conduct of researchResearchCritical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws.Conflict of Interest experiments with human subjects
Places emphasis on voluntary consent and that the person “should have sufficient knowledge and comprehension of the elements of the subject matter involved, as to enable him to make an understanding and enlightened decision.”
1957: In the United States, the first time the principle of “informed consent” was named and became legally binding:
In the case of Salgo v Leland Stanford Jr. University Board of Trustees
The plaintiff, MrMRCalculated as the ratio of the total number of people who die due to all causes over a specific time period to the total number of people in the selected population.Measures of Health Status. Martin Salgo, had arteriosclerosis of the aortaAortaThe main trunk of the systemic arteries.Mediastinum and Great Vessels: Anatomy. A contrast agent was injected into his aortaAortaThe main trunk of the systemic arteries.Mediastinum and Great Vessels: Anatomy to identify blockages, but the procedure resulted in permanent paralysis of his lower limbs.
MrMRCalculated as the ratio of the total number of people who die due to all causes over a specific time period to the total number of people in the selected population.Measures of Health Status. Salgo sued the university medical center and its chief surgeon for lack of disclosure of this potential risk.
The legal ruling was the first to identify the need to provide the patient with information about the potential benefits and the risks of any medical procedure.
1964: Declaration of HelsinkiDeclaration of HelsinkiFirst adopted in 1964 as a set of guidelines for human experimentation published by the World Medical Association.Research Ethics adopted by the World Medical Association (final amendment in 2013):
A statement of ethical principles for medical researchResearchCritical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws.Conflict of Interest involving human subjects, including researchResearchCritical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws.Conflict of Interest on identifiable human material and data.
1966: Henry Beecher, medical ethicist and anesthesiologist in the United States:
Published an article in the New England Journal of Medicine, “Ethics and Clinical Research,” on unethical medical experimentation in the United States
This publication was instrumental in the implementation of U.S. federal rules on human experimentation and regulation of ICICInhaled Anesthetics
1972: “Tuskegee Study of Untreated SyphilisSyphilisSyphilis is a bacterial infection caused by the spirochete Treponema pallidum pallidum (T. p. pallidum), which is usually spread through sexual contact. Syphilis has 4 clinical stages: primary, secondary, latent, and tertiary. Syphilis in the Negro Male”
Study started in 1932, but the participants in the study were not treated, even after penicillinPenicillinRheumatic Fever became the treatment of choice in the mid-1940s
Provoked public outcry, leading to:
$10 million in an out-of-court settlement of a class-action lawsuit on behalf of the study participants in 1974
Creation of the National ResearchResearchCritical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws.Conflict of Interest Service Award Act in 1974
The National Commission for the Protection of Human Subjects of Biomedical and Behavioral ResearchResearchCritical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws.Conflict of Interest in 1974
The Belmont ReportBelmont reportIssued by the National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research, formed after the passing of the Research Act of 1974.Research Ethics in 1979, specifying 3 specific concepts critical to the process of informed consent in researchResearchCritical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws.Conflict of Interest: information, comprehension, and voluntariness
1981 (revised 2018): The Common Rule (Code of Federal Regulations (CFR) 28 Part 46, subpart A):
Called “The Common Rule” because it has been adopted by 17 federal departments and agencies
A rule of ethicsEthicsMedical ethics are a set of moral values that guide the decision-making of health care professionals in their daily practice. A sense of ethical responsibility has accompanied the profession of medicine since antiquity, and the Hippocratic oath was the 1st document to codify its core ethical principles.Medical Ethics: Basic Principles in the United States based on the Belmont ReportBelmont reportIssued by the National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research, formed after the passing of the Research Act of 1974.Research Ethics and the Declaration of HelsinkiDeclaration of HelsinkiFirst adopted in 1964 as a set of guidelines for human experimentation published by the World Medical Association.Research Ethics regarding biomedical and behavioral researchResearchCritical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws.Conflict of Interest involving human subjects
The Common Rule governs institutional review boards for oversight of human researchResearchCritical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws.Conflict of Interest.
The latest revision expresses concern about ICs that are too lengthy and complicated, interfering with comprehension: “Informed consent must begin with a concise and focused presentation of the key information that is most likely to assist a prospective subject or legally authorized representative in understanding the reasons why one might or might not want to participate in the researchResearchCritical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws.Conflict of Interest. This part of the informed consent must be organized and presented in a way that facilitates comprehension.”
The preamble to the revised Common Rule suggests that the following 5 elements be included as the key information summary:
A statement that the project is researchResearchCritical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws.Conflict of Interest and participation is voluntary
A summary of the researchResearchCritical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws.Conflict of Interest, including:
Purpose
Duration
List of procedures
Reasonable, foreseeable risks or discomforts
Reasonable, expected benefits
Alternative procedures or course of treatment, if any
2000: The Office for Human ResearchResearchCritical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws.Conflict of Interest Protections (OHRP) was established in the Office of the Assistant Secretary for Health:
Department of Health and Human Services (HHSHHSDiabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic state (HHS) are serious, acute complications of diabetes mellitus. Hyperosmolar hyperglycemic state occurs due to a relative deficiency of insulin or insulin resistance, leading to severe hyperglycemia and elevated serum osmolality. Hyperglycemic Crises) forms the National Human ResearchResearchCritical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws.Conflict of Interest Protections Advisory Committee (NHRPAC), replaced by the Secretary’s Advisory Committee on Human ResearchResearchCritical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws.Conflict of Interest Protections (SACHRP) to advise HHSHHSDiabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic state (HHS) are serious, acute complications of diabetes mellitus. Hyperosmolar hyperglycemic state occurs due to a relative deficiency of insulin or insulin resistance, leading to severe hyperglycemia and elevated serum osmolality. Hyperglycemic Crises on human subject protection
2005: Universal Declaration on Bioethics and Human Rights (Article 6, General Conference of UNESCO):
“Any preventive, diagnostic, and therapeutic medical intervention is only to be carried out with the prior, free, and informed consent of the person concerned, based on adequate information. The consent should, where appropriate, be expressed and may be withdrawn by the person concerned at any time and for any reason without disadvantage or prejudice.”
“Scientific researchResearchCritical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws.Conflict of Interest should only be carried out with the prior, free, express, and informed consent of the person concerned. The information should be adequate, provided in a comprehensible form and should include modalities for withdrawal of consent. Consent may be withdrawn by the person concerned at any time and for any reason without any disadvantage or prejudice. Exceptions to this principle should be made only in accordance with ethical and legal standards adopted by States, consistent with the principles and provisions set out in this Declaration, in particular in Article 27, and international human rights law.”
“In appropriate cases of researchResearchCritical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws.Conflict of Interest carried out on a group of persons or a community, additional agreement of the legal representatives of the group or community concerned may be sought. In no case should a collective community agreement or the consent of a community leader or other authorityAuthorityMedical Ethics: Basic Principles substitute for an individual’s informed consent.”
Practical Application
When to obtain
Informed consent is obtained for procedures or interventions with significant risks that must be understood by the patient or the surrogate decision-maker.
Includes enrollment in researchResearchCritical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws.Conflict of Interest studies, which also contemplates proper use of data
Although there is no universal rule concerning when and which procedures require consent and documentationDocumentationSystematic organization, storage, retrieval, and dissemination of specialized information, especially of a scientific or technical nature. It often involves authenticating or validating information.Advance Directives, a written consent form is usually prepared for invasive procedures that have relatively higher risks in clinical practice.
Verbal consent is sufficient for minor parts of care (e.g., physical examination, taking blood pressure, taking blood samples); it may also be used if the patient has a disabilityDisabilityDetermination of the degree of a physical, mental, or emotional handicap. The diagnosis is applied to legal qualification for benefits and income under disability insurance and to eligibility for social security and workman’s compensation benefits.ABCDE Assessment that prevents them from signing a consent form.
Legal standards for disclosure
Vary in different states of the United States and in different countries; however, there are 2 main standards for the determination of how much information should be shared:
“Reasonable medical practitioner”: The physician determines how much information should be disclosed.
“Reasonable patient”: The patient decides how much they wish to know.
Prerequisites
Disclosure to the patient of adequate, relevant, and complete medical information needed regarding their condition, name and purpose of treatment or intervention, consequences of refusing treatment, potential risks and benefits, and alternatives.
Determination of patient’s medical decision-making capacityDecision-making capacityDecision-making capacity describes a patient’s ability to make autonomous decisions regarding their care, as determined by a physician.Decision-making Capacity and Legal Competence by the physician
Format and documentationDocumentationSystematic organization, storage, retrieval, and dissemination of specialized information, especially of a scientific or technical nature. It often involves authenticating or validating information.Advance Directives
Consent is formally obtained as a written document signed by the patient and the physician.
Information that must be contained in the informed consent document:
Nature of the procedure or intervention
Risks and benefits of the procedure
Reasonable alternatives
Risks and benefits of alternatives
Assessment of the patient’s understanding
The “teach-back” technique—asking patientsPatientsIndividuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures.Clinician–Patient Relationship or prospective participants to discuss the proposed treatment in their own words—is recommended: allows for gauging comprehension and identifying gaps in participants’ understanding:
“Can you describe the study in your own words?”
“Do you have any questions about the purpose of the proposed treatment?”
Verbal consent must also be documented in the medical record.
Legally, written consent has precedence over verbal consent.
If there is no consent document for a specific procedure, physiciansPhysiciansIndividuals licensed to practice medicine.Clinician–Patient Relationship may write notes about possible risks in the chart.
Coercion from influences outside the patient–physician relationship
External expectations
Poor education
Language barrier
Parental consent or informed permission
Minors (typically those < 18–21 years of age) are by law unable to give consent, so their parents or guardians must give it in their place.
Parents or guardians are considered to have enough decision-making capacityDecision-making capacityDecision-making capacity describes a patient’s ability to make autonomous decisions regarding their care, as determined by a physician.Decision-making Capacity and Legal Competence, and it is assumed they will act in the minor’s best interests.
Children may only express approval (assent).
The Helsinki Declaration requires both informed consent of the parents and the minor’s assent to move forward in a researchResearchCritical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws.Conflict of Interest study.
Emancipated minors:
Minors granted some or all rights and statuses held by adults
Characteristics:
Self-supporting
In the military
Married
Have children of their own
Release of information and informed consent
PatientsPatientsIndividuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures.Clinician–Patient Relationship may be able to allow release of or access to otherwise confidential information about themselves to another person
This access is often important when collateral information needs to be gathered during history taking.
Exceptions to informed consent
Voluntary waived consent
No surrogate decision-maker available
In general, minors do not need parental consent for obstetrical care, treatment of sexually transmitted infectionsInfectionsInvasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases.Chronic Granulomatous Disease, or treatment of substance use disorder.
SuicideSuicideSuicide is one of the leading causes of death worldwide. Patients with chronic medical conditions or psychiatric disorders are at increased risk of suicidal ideation, attempt, and/or completion. The patient assessment of suicide risk is very important as it may help to prevent a serious suicide attempt, which may result in death. Suicide or homicide prevention (via involuntary hospitalizationHospitalizationThe confinement of a patient in a hospital.Delirium)
Lifesaving medical emergency (e.g., in an incapacitated patient) with insufficient time to obtain consent (e.g, MIMIMI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms.Myocardial Infarction)
Informed refusal or informed dissent
The free expression of refusal by the patient, or their surrogate decision-maker, to undergo the proposed treatment or course of action or be involved in the study.
The clinicianClinicianA physician, nurse practitioner, physician assistant, or another health professional who is directly involved in patient care and has a professional relationship with patients.Clinician–Patient Relationship must act in the best interests of the patient and explain the consequences of refusal.
Key Information: The Conundrum of ComplianceComplianceDistensibility measure of a chamber such as the lungs (lung compliance) or bladder. Compliance is expressed as a change in volume per unit change in pressure.Veins: Histology versus Flexibility in Informed Consent
It is challenging to render ICICInhaled Anesthetics easily comprehensible while maintaining complianceComplianceDistensibility measure of a chamber such as the lungs (lung compliance) or bladder. Compliance is expressed as a change in volume per unit change in pressure.Veins: Histology with the legal regulations regarding ICs.
Most ICs are too long and too complex (> 40 pages in some researchResearchCritical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws.Conflict of Interest ICs):
It is recommended to keep the ICICInhaled Anesthetics at the 6th- or 8th-grade reading level.
Flexibility in the presentation of the key information is appropriate if sufficient information is presented in a manner that facilitates comprehension.
Empirical researchResearchCritical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws.Conflict of Interest on the ICICInhaled Anesthetics is ongoing to improve the process.
World Medical Association. (2013). World Medical Association Declaration of Helsinki: ethical principles for medical research involving human subjects. JAMA 310:2191–2194. https://doi.org/10.1001/jama.2013.281053
Brendel, R. W., Wei, M. H., Schouten, R., Edersheim, J. G. (2010). An approach to selected legal issues: confidentiality, mandatory reporting, abuse and neglect, informed consent, capacity decisions, boundary issues, and malpractice claims. Medical Clinics of North America 94:1229–1240. https://doi.org/10.1016/j.mcna.2010.08.003
Beauchamp T. (1997). Informed consent. In: Veatch R, ed. Medical Ethics. 2nd ed. Sudbury, MA: Jones and Bartlett, 1997:185–208.
Foëx, B. A. (2001). The problem of informed consent in emergency medicine research. Emergency Medicine Journal 18:198–204. https://doi.org/10.1136/emj.18.3.198
Vemulakonda, V. M.(2021). Ethics and informed consent. In: Partin, A.W. (Ed.), Campbell-Walsh-Wein Urology, 12th ed., pp 115–118. Elsevier.
Bazzano, L.A., Durant, J., Brantley, P. R. (2021). A modern history of informed consent and the role of key information. Ochsner Journal 21:81–85. https://doi.org/10.31486/toj.19.0105
Kadam R. A. (2017). Informed consent process: a step further towards making it meaningful! Perspectives in Clinical Research 8:107–112. https://pubmed.ncbi.nlm.nih.gov/28828304/
Cordasco, K. (2013). Obtaining informed consent from patients: brief update review. Chapter 39 of Making Health Care Safer II: An Updated Critical Analysis of the Evidence for Patient Safety Practices. Retrieved January 26, 2022, from http://www.ncbi.nlm.nih.gov/books/NBK133402/