Intended for healthcare professionals

Education And Debate

Theories of consent

BMJ 1998; 317 doi: (Published 07 November 1998) Cite this as: BMJ 1998;317:1313
  1. Priscilla Alderson, reader in sociology,
  2. Christopher Goodey, research officer
  1. Social Science Research Unit, Institute of Education, University of London, London WC1H ONS
  1. Correspondence to: Dr Alderson

    This is the third in a series of six articles on the importance of theories and values in health research

    Series editor: Priscilla Alderson

    Consent is understood differently by various disciplines and professions, and also in various theoretical models.1 In this article we review the advantages and limitations of theories about real consent, constructed consent, functionalist and critical consent, and postmodern choice. The article shows how an analysis of theories can clarify practical knowledge about the advantages of and problems in obtaining consent, which will help everyday practice and research.

    Summary points

    Consent is understood and discussed in contradictory ways when people rely on different theoretical models

    Positivism assumes that there is real consent in the factual exchange of medicolegal information

    Social constructionism shows how consent can be a complex, ambiguous process, not a simple event

    Functionalists see consent as a formality, whereas critical theorists see it as a vital protection

    Postmodern theories illuminate the confusions that arise when choice itself is assumed to matter more than any of the options chosen

    Consent is too complex to be explained by any one theoretical model

    Real consent

    Positivism distinguishes factual concepts defined through dichotomies: informed/ignorant, competent/incompetent, free choice/coercion. Medicine, psychology, analytical philosophy, 2 3 and law 4 5 tend to assume positivist concepts of consent. The appropriate information, including percentage risks, for obtaining informed consent is treated almost as a “thing” which doctors give to patients. It is assessed by checking how patients recall and recount standard details of the information they have been given.

    Positivist surveys dominate research about consent; mainly they measure information given. The essence of consent (patients' thoughts, feelings, and values as they evaluate information and make and express their decision) is far harder to observe or record—and too subjective and elusive to count as hard data. Problems in real consent are attributed to patients' and doctors' limited knowledge and communication skills, and are addressed by efforts to improve knowledge and skill. Social pressures, and great anxiety and distress, are assumed to inhibit patients' ability to make independent, rational choices, and so should be reduced or avoided if possible.

    The respect for informed consent within a positivist framework brings important benefits. It encourages health professionals to be accountable and to know and explain clearly what they plan to do, and why. Basic information standards are agreed (see box) and are achieved partly through research, audit, and professional education, which also improve health care. Respect for patients' consent or refusal expresses precious ideals of respect for their physical and mental integrity. It defends them from unwanted interventions and from deception or coercion during treatment and research. Yet positivist theories set such high standards that many people are classified as too ignorant, too dependent, or too emotional to be competent. In an all or nothing approach, consent is seldom discussed in relation to good practice with supposed “incompetents.”6 Sharp dichotomies are unhelpful in assessing borderline cases, though in these the need for helpful theories of consent and competence is greatest. Because real consent is unrealistic for many ordinary people, clinicians and researchers feel cynical, irritated, or despondent about consent.

    Types of consent

    Informed consent involves knowing about7:

    • The nature and purpose of the intervention

    • Intended effects and unintended side effects

    • Risks, harms, and hoped-for benefits

    • Any reasonable alternatives

    Voluntary consent involves:

    • Freedom from “force, fraud, deceit, duress, overreaching or other ulterior form of constraint or coercion”8

    • Knowing about the right to refuse or withdraw, without prejudicing further health care

    • The right to ask questions and to negotiate aspects of treatment coerced perhaps by disease, but not by other people

    Consent to research involves knowing about:

    • The research purpose, questions, aims and methods

    • Relevant terms like “randomise”

    • The treatment, if any, which the research investigates

    • Benefits, risks, harms, or costs to research subjects

    • Hoped-for benefits to other groups such as future patients

    • Confidentiality, indemnity, sponsors, ethical approval

    • The research team and a named contact

    (Some of these details can be explained in leaflets and discussed with those who ask about them)

    Competent consent:

    • Involves the person being able to make and stand by an informed, freely made decision.

    Adults can decide as they please, but a minor, in the opinion of the treating doctor,9 must have “sufficient understanding and intelligence to understand fully what is proposed,” be “capable of making a reasonable assessment of the advantages and disadvantages of the proposed treatment,” and have “sufficient discretion … to make a wise choice in his or her own interests.”10

    Constructed consent

    From a range of social construction theories we review a few ways of understanding consent. Modern ideas of consent began in the late 17th century and are used in varying and contradictory ways. Sometimes the same person unwittingly uses different theories.

    The two main components of modern consent are understanding and voluntariness. These originate from 17th century religious belief that the intellect and the will are the two things that make us human. Thus theories of consent are based on personal and social beliefs about human nature. Consent is integral to modern democracy, which was also born at that time as the idea that we have enough understanding and will to withdraw consent from inadequate rulers. Theologians argued then about whether the intellect or the will was more important for obtaining redemption, and about the exact relation between them. Consent was seen largely as an act of the will.

    Some modern interpretations of consent emphasise patients' understanding: once that is programmed, voluntariness is simply a mouse that clicks “ok.” Yet decisions may involve a process of voluntariness or unwillingness, with complex desires and resistances. Desires and feelings can confuse understanding but also enrich it. Initially, patients often want to reject dangerous, unpleasant treatments. Before they can willingly consent, they have to journey from fear of the treatment into greater fear of the untreated condition, with growing trust in their health carers. Parents consenting to their baby's heart surgery, for example, are bewildered but also undergoing emotions of fear, anguish, empathy, hope, and courage. If they were as emotionless as theories of real consent expect, they could not really understand or consent. Theories of how people construct their identity by telling and retelling accounts of their lives—while moving from fear towards hope, for example—can explore experiences that elude standardised surveys. Through lengthy research interviews, ordinary people show how profoundly they understand and reframe concepts of altruism or autonomy, responsibility and risk.11

    Professional assessments of adequate information and competence to consent can similarly be seen as varying social constructs, not universal standards. Some doctors consider that young children are competent to consent; others say that patients can “never” adequately understand.6 Positivism tends to see patients' abilities as fixed personal attributes. Social construction sees them partly as responses in relationships, influenced by the professionals' abilities to explain, respect, and support. Patients who are initially assumed to be incompetent may then be helped to attain understanding and resolve to a degree which they and their health carers regard as competent. They may decide about certain aspects of treatment and share or refer other decisions; being able to decide differs from wanting to be the responsible decider.

    In real consent, all influences tend to be seen as potentially coercive pressures, and autonomy is seen as free-floating individualism. Social construction shows how, without numerous social and personal influences, we would not have choices or the ability to choose between them. A 14 year old boy with cystic fibrosis whose brother had died of the disease was asked if he really wanted to have the recommended heart-lung transplant. He answered, “My mother would be so sad if I did not have it.” Relationships can enrich as well as restrict the autonomy to consent.12

    By holding individual agents and social structures, and interactions between them, in tension, construction theories provide a framework for case studies of consent as process rather than event. These range from individuals' narratives to studies of surgical units. They show how patients may be influenced by their family and friends, memories, the media, and hospital staff, who all make up a coherent (or confusing) jigsaw of knowledge. The type of unit and of treatment, whether treatment is elective or emergency, how complex and risky it is, and the time, space, and resources available all influence individuals' responses. Detailed studies can show the extra complications in daily practice in each clinical specialty and ways these might be dealt with.

    One problem in social construction theories is that of becoming so absorbed in variety and complexity that the essential kernel in “real” consent (see box), along with respect for individual integrity, is lost. All researchers potentially face difficulties in justifying their selection of theories, questions, and data; their interpretations; and the validity and generalisability of their work. These difficulties are especially obvious and central in research that uses case studies. Because it collects vast amounts of data, a further problem is its unpopularity with clinicians who would like research to have clear, easily applied conclusions.

    Functionalist consent

    Functionalist consent is a polite ceremony, a token of respect that is hardly necessary because benign, expert doctors contribute to the smooth functioning of society; refusal and non-compliance are irrational. Consent is, however, a convenient means of transferring responsibility for risk from the clinician or researcher to the informed patient, thus enabling treatment and research to proceed without serious risk of costly litigation. English courts usually support the doctors in disputes about consent, 13 14 and psychiatrists can advise in cases of seemingly irrational refusal by minors. 15 16 Most people are partly functionalists in that they need to be members of a coherent society with some consensus on stable, useful knowledge. Many doctors would not explicitly support extreme functionalism, but in busy wards, clinics, and surgeries consent tends to be treated as a simple or tedious formality.

    Critical theory

    The opposite view sees consent as a necessary protection for patients against useless, harmful, and unwanted interventions; an occasion when doctors have to be accountable; and an essential constraint on the most powerful profession.17 Informed consent is not regarded as simple, one way medical information giving, but as an exchange of knowledge between doctor and patient so that together they can make more informed decisions.


    Valid consent to treatment may involve an intellectual and emotional journey of growing understanding

    Postmodern choice

    In postmodern societies, people generally have moved from being producers in factories, farms, or mines to being consumers whose highest value is choice. Theories of critical and real consent, that are mindful of the serious political and legal history of rights, respect for personal integrity, and, if necessary, defence against atrocity8 seem to shrivel into a choice of trivial “pick n' mix” options. Significantly, the British government's Patient's Charter does not give legal entitlements but quality checklists, treating citizens as consumers.

    Postmodernism's analysis of various forms of consumption18 can be amply illustrated by examples taken from health care. The identity seeker looks for a facelift, a sex change, or a designer baby. Even people having mundane treatment, who do or do not make it their main topic of conversation, thereby shape their identity. The consumer who reads Which? magazine studies expert advice and calculates the “best buy” treatment. Political consumers campaign for ethical care and fair rationing; green consumers are keen on keeping fit and on products that are not derived from animal experiments. Consumers as explorers go in for the exotic: experimental treatments or New Age ones, perhaps. Hedonists consume for pleasure, glamour, and attention, and are seen in advertisements for private health insurance and health farms.

    All this may seem a travesty of real consent and serious medicine. Yet postmodernism contributes important insights. Social and economic forces ensure that everyone in wealthy societies is a consumer. We expect to be offered choices—of groceries, shoes, radio channels, or holidays—and do not suddenly change when we become ill or injured. Doctors are among the leading purveyors of choices from before the cradle to the grave: prenatal screening; analgesia during childbirth; growth treatments; prostate surgery or watchful waiting; organ transplant or acceptance of death. Much treatment is not for serious disease but for convenience, such as to hasten recovery from minor illness. Even consent to major surgery, like hysterectomy or spinal fusion, may be influenced more by personal preferences than by clinical judgment. Doctors also expand notions of choice into areas once thought to be immutable—for example by altering bodies through surgery and minds through drugs, and promising to alter identities through gene therapy. There are curious contradictions between seemingly momentous decisions or trivial choices. Are terminations for fetal abnormality, or prescribing ritalin to a difficult child, sensible routines—or are they part of great transformations in our understandings of human nature, relationships, and obligations? Although seeming to expand choice, do they close other options and ways of living and relating and impose a tyranny of choice? Choice can be more onerous when people are uncertain how to choose among values and rules for choice making.

    Choosing among theories

    Consent is a strong concept in being so versatile and durable, but it is vulnerable to conflicting interpretations and rejection as a worthless ideal. Real and critical consent remind practitioners and researchers about standards that protect them and their patients; these are at times too high to achieve, but they endure as standards to aim for. Functionalist consent reflects common medical practice, if not medical values. Social construction shows how consent is a process—perceived, experienced, and shaped through interactions between individuals and their social contexts. Postmodernism provides revealing descriptions of current contradictions and confusions in consent, which is usually assumed to epitomise rational and moral certainties. Consent is too complex to be understood fully in any one theoretical model.


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