chapter  2
Consent to investigation and treatment: who is competent to give consent?
Pages 10

Introduction The validity of a patient's consent depends on a number of factors. One of these factors, which is central to the process, is the question of a patient's competence. The range of ability among patients follows a continuum from incompetence through to competence. A practical question for clinicians is where on that continuum they must place a marker below which a patient would be unable to give consent because they lacked competence. A simple approach is to suggest that the status of a patient can be used to define whether they have competence. In this situation, minors and those with mental disorders could be said to lack competence. Such approaches have been challenged, and will be reviewed in this chapter. In England and Wales, assessment has been based on capacity, and in practice:

The right to decide one’s own fate presupposes a capacity to do so. Every adult is presumed to have that capacity, but it is a presumption which can be rebutted. This is not a question of the degree of intelligence or education of the adult concerned.1