The legal principles applicable to patients who refuse consent to medical treatment are relatively simple. The problem comes when seeking to apply the principles to particular facts. A competent adult has an absolute right to decline medical treatment (subject only to the provisions for compulsory treatment of mental disorder or illness under the Mental Health Act 1983). This right exists “notwithstanding that the reasons for making the choice are rational, irrational, unknown or even non- existent.”1 Thus, provided that the two patients were competent to consent, and hence to refuse consent, the doctors were correct to respect their decision to refuse blood transfusions, irrespective of the consequences.

In a Canadian case an accident and emergency doctor who gave blood to an unconscious Jehovah's Witness knowing that she carried a signed card indicating that she …