The Age of Legal Capacity (Scotland) Act, 1991  creates a presumption of capacity for all adults aged 16 years or over. Where doubt exists, the health professional should assess the capacity of the patient to take a decision relating to care. A patient can only be judged to lack capacity to make a specific decision at a specific time as their capacity can be temporarily affected by factors such as confusion, unconsciousness, panic, shock and pain. Consent issues relating to adults without capacity are addressed in section 4, and for those under 16 years of age in section 7.

Decision making capacity requires:

• An awareness that there is a decision to be made.
• An understanding of the patient’s specific condition(s) and impact upon being able to give consent.
• Adequate comprehension i.e. an understanding of the nature and possible advantages and disadvantages of the treatment proposed.
• Access to knowledge in relation to decision (i.e. have recall or recognition) and be able to do so consistently.
• An ability to express themselves.

Care should be taken not to underestimate capacity. Many people with cognitive impairment have the capacity to consent in relation to certain aspects of their care, if time is spent explaining the issues, using visual aids and addressing any impairments the person may have if necessary. Where appropriate, those who know the patient well, including their family, carers and staff may be able to give advice on the best ways to communicate with the person. In any event, it is important to seek the views of the patient, where possible.

Capacity should not be confused with the health professional’s assessment of the reasonableness of the patient’s decision. The patient is entitled to make a decision that is based on their own religious belief or value system, even if others do not understand it, or it results in the person experiencing further problems (including death), i.e. what clinicians might consider a `bad` decision. The important factor is that the patient understands what is entailed in his/her decision, and the consequences of that decision.