Informed consent

voluntary consent given by a person or a responsible proxy (e.g., a parent) for participation in a study, immunization program, treatment regimen, invasive procedure, etc., after being informed of the purpose, methods, procedures, benefits, and risks

Description
The essential criteria of informed consent are that the subject has both knowledge and comprehension, that consent is freely given without duress or undue influence, and that the right of withdrawal at any time is clearly communicated to the subject. Other aspects of informed consent in the context of epidemiological and biomedical research, and criteria to be met in obtaining it, are specified in International Guidelines for Ethical Review of Epidemiologic Studies (Geneva: CIOMS/WHO 1991) and International Ethical Guidelines for Biomedical Research Involving Human Subjects (Geneva: CIOMS/WHO 1993).