Difficulties in consent: applying the Mental Capacity Act

In England and Wales, the law in relation to capacity is based predominantly on the Mental Capacity Act 2005. The Mental Capacity Act is reflected in guidance published in 2008 by the General Medical Council.1 It contains clear principles that need to be applied in practice and are important for doctors to understand to ensure that they are not practising outside the law.

Understanding the basic legal principles behind the Mental Capacity Act makes it easier to obtain valid consent. However, the Mental Capacity Act should also be viewed within the context of other case law.

The process of assessing capacity has been criticised on the basis that the concept of capacity overlooks the inherent difficulties of comparing judgments about whether a patient is using or weighing information in the decision making process in comparison to an ideal standard or model.2 Nevertheless, failure to follow this guidance renders a doctor liable to disciplinary proceedings brought by the GMC.

The first principle of the Mental Capacity Act is the presumption of capacity. As with any presumption, this can be rebutted in the presence of evidence supporting a contrary conclusion, but it is important that doctors adopt the mindset of a presumption of capacity.

The adoption of this presumption has effectively lowered the threshold for capacity so that more patients would be expected to be deemed to have capacity. Concerns have also been raised that clinicians are now overestimating patients’ capacity.3

Patients should be provided with all necessary assistance, support, and guidance to facilitate the maximisation of their capacity. A doctor should consider whether patients can, in turn, understand, retain, use, and weigh up information provided.

The GMC guidance is explicit about dangers inherent in this process. It states1: “You must not assume that a patient lacks capacity to make a decision solely because of their age, disability, appearance, behaviour, medical condition (including mental illness), their beliefs, their apparent inability to communicate, or the fact that they make a decision [with which] you disagree.”

A patient may have capacity for some decisions but not for others, depending on the complexity of the decision. A decision to take blood, for example, is relatively straightforward. Many patients will have the requisite capacity to give consent for blood to be taken but may not have capacity for more complex decisions, such as those surrounding oncological interventions. It is helpful to give the patient a written record of what has been discussed and agreed. This is useful if any future disputes arise about capacity.4

The appropriate legal test as to whether capacity is present in borderline situations is whether it is more likely than not that capacity is present. But more important decisions do not require a doctor to be more certain that capacity is present—the test remains simply whether it is more likely than not that a patient has capacity.5

There are a number of situations where problems relating to capacity have a higher risk of occurring by virtue of patient vulnerability. These include patients with neurological conditions, patients residing in a care home, and situations where mental health legislation is engaged or where a patient is in police, immigration, or prison detention.

It is important to differentiate between a patient lacking capacity and a patient’s decision being deemed wrong or irrational. Provision of consent is an ongoing process. Doctors should be aware of fluctuations in capacity, which may mean that consent as originally provided may no longer be valid given a change in circumstances. This problem can often be dealt with through discussions to determine a patient’s wishes in the event of future eventualities. This will assist in determining what actions would be in a particular patient’s best interests.

It is a cardinal error to make an initial assessment of capacity and apply it unthinkingly in future interactions. The corollary is that a previous assessment that capacity is absent does not mean that the patient may not develop capacity in the future.

Doctors operate as part of multidisciplinary teams. Where a doctor has doubts about a patient’s capacity, particularly in situations where a patient is vulnerable, the doctor should seek advice from others who may be in more frequent contact with the patient, including nursing staff,6 carers, and the patient’s family. Doctors should also approach colleagues with specialist skills who may assist, including neurologists, psychiatrists, and speech and language therapists.

If doubts as to a patient’s capacity remain, a doctor must seek legal guidance specifically with a view to obtaining a determination from a court in relation to the patient’s capacity. It is considered good practice to inform the patient, their representatives, and others close to them to enable them to obtain prompt legal representation during such a process.

Patients may have capacity even if the result of their decision is deemed irrational and could result in the loss of life. Even placing the life of an unborn child at risk may not be enough for a patient’s wishes to be over-ridden. Doctors should be especially alert to any possibility of duress being placed on a patient that affects capacity, as well as the effect of any medication being administered.