informed consent [L, informare, to give form, consentire, to sense] , permission obtained from a patient to perform a specific test or procedure. Informed consent is required before most invasive procedures are performed and before a patient is admitted to a research study. The document used must be written in a language understood by the patient and be dated and signed by the patient and have at least one witness. Signed consent should be obtained by the person performing the procedure. Included in the document are clear, rational statements that describe the procedure or test. Also required is a statement that care will not be withheld if the patient does not consent. Informed consent is voluntary. By law, informed consent must be obtained more than a given number of days or hours before certain procedures, including therapeutic abortion and sterilization, and must always be obtained when the patient is fully competent. An individual must be of a certain legal age to give consent; laws vary from state to state. Compare implied consent.
