The right to autonomy and individuals decision-making freedom presumes that the person has the capacity to make the decision in question. ‘To be autonomous requires a person to have the capacity to deliberate a course of action, and to put that plan into action’ 5. The involuntarily treatment of a patient with capacity results in the doctor committing battery.
The Mental Capacity Act 2005 governs the law on capacity, however the development of and the importance of autonomy within medical law were established through case law.6 The criteria for capacity cannot be set to low or high otherwise patients will be disempowered which is in conflict with the objectives of The Mental Capacity Act. If a person has capacity they may act autonomously and make decisions for themselves that may have serious or fatal consequences.7The test of capacity must therefore be robust enough to preserve the decision-making freedoms of individuals whilst safeguarding vulnerable patients. The MCA introduced ‘a substantial degree of clarity’8 by providing a legal framework to establish capacity and to recognise the rights and protect those who lack capacity.9
The Mental Capacity act uses an issue specific definition of capacity, this means that capacity is fluid and a person can have capacity one day but not the next (due to fluctuating cognitive facilities) or from one decision to another dependent on the issue As stated by Chadwick LJ ‘the test of capacity has to be applied in relation to the particular transaction (its nature and complexity)’.10 There is a presumption that every adult has capacity11, the burden of proof to prove otherwise is on the Doctor. The MCA adapted from common law12 a two stage functional test. Firstly a diagnostic test of cognitive functions .The MCA states ‘A person lacks capacity in relation to a matter if, at the material time he is unable to make a decision in relation to the matter because of an impairment of or a disturbance in the functioning of the mind or brain’.13
Secondly, a test to determine that this impairment results in that person being unable to make the decision.14 Section 3 defines a person as unable to make decisions if they cannot understand the information relevant to the decision, retain that information, use or weigh that information as part of the process of making the decision, or communicate his decision.15 As established by Chatterson a patient only needs to understand in ‘broad terms’ the nature of the procedure.16They need to have the ability to understand not necessarily to have actual understood the relevant information.17 They need not retain the information for a set period of time18they also do not have to believe the information as long as they understand it.19 The patient must be able to use the information to make a decision. The inability to use the information and reach a decision may be affected by factors such as confusion, pain20 or the influence of another person.21 However the presence of such factors does not automatically equate to a lack of capacity these