NICE Guideline NG108 - Decision-making and mental capacity
Section 3(1) of the Mental Capacity Act 2005 makes clear that a person will be unable to make a decision for themselves if they are unable to understand the information relevant to the decision. Case law has confirmed that the information to be provided to the person regarding the decision does not have to include every single detail relating to the decision, but must include the 'salient factors'. The salient factors are those which are most important to the decision to be made. This would include information that is subjectively important to the person being assessed (for example information relating to the likely level of disability a person would have if they did/did not undergo the treatment in question) and also key pieces of objective/factual information relevant to the decision to be made (for example the side effects of a particular treatment, or the known complications or survival rates of a particular surgical procedure). The seriousness of the decision, and the timeframe within which it must be made, will impact on the nature and amount of information that will need to be provided to the person.