Capacity

(i) Law

Based on a respect for individual autonomy, adults [185] are presumed to have the capacity (or competence) to decide whether to consent or to refuse an examination, investigation, procedure or treatment such that their decision is regarded as responsible and must be respected. Although capacity involves understanding and maturity, a patient should not be considered as lacking capacity just because they make an unwise decision or one that is against their own best interests [186] . In law, having capacity is not the same as making a decision that others would perceive as reasonable, rational or sensible. Lord Donaldson [187] explained:

“ An adult patient who…suffers from no mental incapacity has an absolute right to choose whether to consent to medical treatment, to refuse it, or to choose one rather than another of the treatments being offered … This right to choose … exists notwithstanding that the reasons for making the choice are rational, irrational, unknown or even non-existent. ”

A similar statement was made by Butler-Sloss LJ:

“ A decision to refuse medical treatment by a patient capable of making the decision does not have to be sensible, rational or well-considered … ”.

Hence, a patient is entitled to make a decision based on their own value system, provided that they understand what their decision involves and their determination is not based on a misperception of reality due to a lack of capacity. However, the presumption of capacity is open to legal rebuttal [188] with the onus being upon those seeking to argue that the individual lacks capacity [189] . An obvious example would be if a doctor treated an unconscious adult of sound mind in an emergency, in the patient's ‘best interests', with a life saving treatment that could not be delayed safely until consciousness returned.

However, the quality of capacity is not an ‘all or none' faculty but represents a spectrum of natural abilities to make reasoned decisions. Untrained laypersons may have difficulty in assimilating and evaluating technical details while ‘information overload' may obscure essential factors of a treatment proposal. Hence, the more that a person must comprehend before making a decision the less likely they will have the necessary capacity to decide. Since different levels of capacity are required to make different decisions, depending on their complexity and gravity, the doctor has a duty to ensure that the information provided is intelligible and relevant to that individual.

Capacity may fluctuate in an individual and also be affected temporarily by factors such as confusion, panic, shock, fatigue, pain, illness or medication. The case of Re MB [190] is illustrative. The patient was informed that a caesarean section would substantially improve her baby's chances of survival since it was in the breach position. The patient consented to the procedure more than once but then, at the last moment, withdrew consent due to an irrational fear of the anaesthetist's needle. The Health Authority sought a declaration that it would be lawful to operate as the doctors believed that the patient clearly understood the need for a caesarean section but lacked appropriate capacity when in the immediate proximity of a needle. Butler-Sloss LJ stated:

“ … Capacity is commensurate with the gravity of the decision to be taken … She could not bring herself to undergo the caesarean section she desired because, as evidence established, ‘a fear of needles … has got in the way of proceeding with the operation … At the moment of panic … her fear dominated all ... at the actual point she was not capable of making a decision at all … She was at that moment suffering an impairment of her mental functioning which disabled her. She was temporarily incompetent … ”.

In the case of Re C [191] , Judge Thorpe established the three-stage common law test for capacity. A patient is regarded as having capacity if, ‘on the balance of probability', they pass each of the following criteria ( authors' italics ):

•  Comprehend ( in broad terms the nature, purpose and effect of the proposed procedure ) and retain the ( relevant ) treatment information ( long enough to make a decision to consent or refuse to consent );

•  Believe the information given; and

•  Weigh it (i.e. the information ) in the balance ( to assess risks vs. benefits and have the ability ) to make a ( free ) choice.

The criteria for deciding the competence of an adult to consent for therapeutic and non-therapeutic research is the same as in the clinical setting. However, since therapeutic research has a dual purpose of combining professional care with scientific enquiry to contribute to general knowledge, the doctor has an additional duty to be satisfied that the patient is competent to provide consent, having taken into account pertinent factors associated with that patient's existing medical condition and any concurrent therapy. Hence, the patient taking part in research must be provided with the fullest possible information presented in terms and a form that they can understand. Incapacity makes consent to non-therapeutic research unobtainable. The DOH [192] and the GMC [193] have issued detailed guidance on these matters.

NOTES

[185] A person reaching the age of 18 is assumed to be a competent adult. Under s8 of the Family Law Reform Act 1969, a young person aged 16 or 17 may consent to medical treatment, a parent or guardian may consent for a child or a child under 16 years of age may give consent if he/she has sufficient intelligence, maturity and understanding so as to satisfy the ‘ Gillick criteria ' in Gillick v Norfolk and Wisbech Health Authority [1985] 3 All ER 402; [1986] AC 112.

[186] For example, Re JT (Adult: Refusal of Medical Treatment) [1998] 1 FLR 48, a mentally disabled female developed life-threatening renal failure and refused dialysis as she wanted to die. The court decided that she had capacity to refuse and realised the consequences of that refusal or in Home Secretary v Robb [1995] 1 FLR 412; [1995] 1 All ER 677 when a competent adult hunger striker was allowed to refuse food.

[187] Re T (An Adult) (Consent to Treatment) [1992] 4 All ER 649 at 653 (CA); (1992) 9 BMLR 46 at 50.

[188] Re T (Adult: Refusal of treatment) [1992] 4 All ER 649 at 661 per Lord Donaldson, “ … every adult is presumed to have … capacity [to consent], but it is a presumption which can be rebutted”.

[189] The BMA have published advice on assessing capacity which appears in a report of the British Medical Association and The Law Society, Assessment of mental capacity: guidance for doctors and lawyers, 1995, London BMA.

[190] In Re MB (An Adult: Medical Treatment) [1997] 38 BMLR 175 CA, Butler-Sloss LJ stated “A person lacks capacity if some impairment or disturbance of mental functioning renders the person unable to make a decision whether to consent to, or to refuse, treatment. …”

[191] Re C (Adult: Refusal of Treatment) [1994] 1 All ER 819 (Fam Div); [1994] 1 FLR 31 at 33E; [1994] 1 WLR 290.

[192] Reference Guide to Consent for Examination or Treatment, Chapter 1, paragraphs 2.0-2.7. Department of Health 2001.

[193] Seeking patients' consent: the ethical considerations, Paragraph 19, November 1998, London, GMC; Research: The role and responsibilities of doctors, Paragraph 43-46, 2002, London, GMC.