Table 1 Definitions of terms

Capacity to consent

The person should have the capacity to make a choice about the proposed course of action, knows about the study risks, benefits and alternatives, understands that consent is ‘voluntary and continuing permission’, and understands that consent can be withdrawn at any time.

Prospective informed consent

The decision (written, dated and signed) to take part in a study, which is taken after the person is fully informed about the study nature, its significance, implications and risks. Informed consent can be given by any person capable of giving consent or, where the person is not capable, by a surrogate decision maker. Oral consent in the presence of a witness may be given in exceptional cases.

Third-party consent

Informed consent to research participation is provided by a surrogate or proxy decision maker, for example, a family member or legal representative where the potential participant is unable to provide consent themselves. Proxy consent can also describe the process by which people with the legal right to consent for themselves or as a surrogate can delegate that right to another person.

Deferred consent

When a patient is enrolled into a study, and consent is taken later, either from a surrogate decision maker or from the patient when he/she is able to provide informed consent.

Waiver of consent and Exception from informed consent

A consent procedure that alters elements of informed consent or waives the requirements to obtain informed consent. For example consent may be waived if the research presents no more than minimal risk of harm to subjects and could not be carried out without a waiver.

Exception from informed consent may also apply for enrolment of participants in emergency research. Here, requirements include consultation with representatives of and public disclosure to the communities in which the study will be conducted prior to study initiation. Deferred consent is still a requirement in most cases.