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5. Assessment of competence

Are adults presumed to be competent to give consent?

Yes. All people aged 16 and over are presumed, in law, to have the capacity to consent to treatment unless there is evidence to the contrary.

A patient who is suffering from a mental disorder or impairment does not, necessarily, lack the competence to consent to treatment. Equally, patients who would otherwise be competent may be temporarily incapable of giving valid consent due to factors such as fatigue, drunkenness, shock, fear, severe pain or sedation.

The fact that an individual has made a decision that appears to others to be irrational or unjustified should not be taken as evidence that the individual lacks the mental capacity to make that decision. If, however, the decision is clearly contrary to previously expressed wishes, or is based on a misperception of reality, this may be indicative of a lack of capacity and further investigation will be required. (See also Card 1 list: ‘Consent’, ‘Capacity’, ‘MCA’, ‘DoH’, ‘MET’, ‘MDU’, ‘MPS’.)


Are children and young people presumed to be compentent to give consent?

No. There is no presumption of competence for people under 16 and those under this age must demonstrate their competence by meeting certain standards set by the Courts. In England, Wales and Northern Ireland, the central test is whether the young person has sufficient understanding and intelligence to understand fully what is proposed.

In Scotland, a young person is considered competent to make treatment decisions if he or she is capable of understanding the nature and possible consequences of the procedure or treatment. (See also Card 7 on children and young people and Card 1 list: ‘0-18 years’, ‘Children’.)


What factors should be taken into account when assessing competence to consent to treatment?

The assessment of a patient’s capacity to make a decision about medical treatment is a matter for clinical judgement guided by professional practice and subject to legal requirements. To demonstrate capacity individuals should be able to:

  • understand (with the use of communication aids, if appropriate) in simple language what the medical treatment is, its purpose and nature and why it is being proposed
  • understand its principal benefits, risks and alternatives
  • understand in broad terms what will be the consequences of not receiving the proposed treatment
  • retain the information for long enough to use it and weigh it in the balance in order to arrive at a decision
  • communicate the decision (by any means).

In order for the consent to be valid the patient must be able to make a free choice (ie free from pressure).

(For other aspects of competence and for practical guidance, see Card 1 list: ‘Consent’, ‘0-18 years’, ‘Children’, ‘Capacity’ ‘MCA’.)


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Card 5: Assessment of competence