Informed consent

Everyone taking part in a clinical trial must give ‘informed consent’, or have a parent or guardian or other legally authorised person give consent.

Informed consent means that potential participants are given information about the key facts of a clinical trial before deciding whether or not to take part. Informed consent also means that participants are provided with information on new developments throughout the trial.

You cannot be entered into a trial if you don't want to be. If you are asked to take part, you are free to say yes or no at any time. There should be no pressure on you to enter a trial. If you are under 18, a parent or guardian has to give legal consent and you have to give your permission as well.

To help you decide whether or not to be part of a trial, members of the research team will explain the details of the trial to you. The researchers will also provide a document, usually called a participant information and consent form, which includes details about the study such as its purpose, duration, required procedures, risks and potential benefits. You can ask about anything that is not clear to you or that you do not understand. You can take your time and talk it over with family and friends or your own doctor before deciding whether to take part.

You will then decide whether or not to sign the consent document. Signing the consent document means that you are agreeing to take part in the trial and have understood what that will involve. The consent document is not a contract, and you may withdraw from the trial at any time. If you do withdraw from a clinical trial, the relationship between you and your doctor will not be affected.

If there are any changes to the trial or to the protocol, you will be kept informed and you may be asked to give your consent again before proceeding with the trial.

Giving consent for another person

Sometimes, a potential participant may be unable to give their own consent for participating in a clinical trial. Such people might include:

  • those who may be temporarily unable to give consent, including unconscious patients
  • those with a severe cognitive impairment, an intellectual disability, or a mental illness, including elderly patients with dementia
  • children who are not able to give consent.

In these circumstances, consent may sometimes be given by responsible family members, guardians or someone authorised by a court to act on behalf of the person who is not able to give informed consent.

In some cases, family members or guardians may also be needed to help a person make the decision about whether or not to take part in a clinical trial (even though the person will need to provide their own informed consent). This is particularly the case for people with a less severe cognitive impairment, intellectual disability or mental illness, or for those whose first language is not English.