What makes a directive valid?
D016223:Advance Directives; D003657:Decision Making; D036262:Empirical Research; D005066:Euthanasia, Passive; D005069:Evaluation Studies as Topic; D006801:Humans; D007258:Informed Consent; D008722:Methods; D012015:Reference Standards; D012106:Research; D020458:Third-Party Consent
Death and Euthanasia; Empirical Approach