Clinical trials & medical research

Making the decision to take part and giving assent and consent

A doctor, nurse, or other researcher should always give you information about what is involved to help you decide whether to take part in a clinical trial. If you are aged 16 years and older you cannot take part in a trial unless you have given your consent and signed a form to say you agree to take part. 

If you are under 16 years of age, you cannot give formal legal consent - this has to be given by a parent or guardian - but you should be involved in the decision as far as possible. In this case, you may be given an ‘assent’ form to sign. 

Assent means children give their permission or agreement to take part in trials. To give assent children need to understand the research process and be informed about what they are expected to do. All children have the right to receive information given to them in a way that they can understand, and to consider assenting, or not (to say they agree to take part, or not). In deciding whether to give assent, children can express their views and any worries about taking part. Doctors need to listen to the opinions and wishes of children who are unable to give full consent, and do their best to help them. Consent from parents and assent from children are both needed for children under the age of 16 to take part in trials.

It is important that you have enough information to give informed consent, or assent, and an opportunity to ask as many questions as you like. You should also be given time to make a decision. (See ‘Being invited to take part in a clinical trial' information and questions’).The UK Clinical Research Collaboration booklet on ‘Understanding Clinical Trials’ has a checklist of questions you might like to ask. You can print off the pages which include space to jot down your own notes. 

People have different preferences for how much information they want. To help you decide whether to agree to take part, the researcher should explain'

The aim of the study – what it is trying to find out

How you will be treated and what you will need to do

What the possible risks and benefits are

Before making the decision to take part, most of the young people we talked to discussed the trial with their parents. Sometimes it was a joint decision. Sometimes young people discussed it with other family members and close friends too. 

Some young people we interviewed were in hospital when they were invited and were unsure about taking part because they had just been diagnosed or were feeling poorly.

In all cases, and however little time is available to make a decision, there should never be any pressure on you to take part in a trial. Most young people we talked to recalled being told it was their decision, and most remembered being given plenty of information and explanation about the trial without probing them for a decision. Sometimes young people had a feeling that health professionals were really hoping they would say yes, even if they did not say so.

Clinical trials are done because there is a possibility that a new treatment will be better than an existing treatment. It may have already been shown to work for other conditions or other groups of patients. However, trials are just as likely to find that new treatments are worse than existing treatments. Patients who desperately want to get better may interpret doctors’ words in a way doctors do not mean, or, ‘read between the lines’. This underlines the importance of staff being very careful about what they say, and how they say it. 

Young people may feel that there are benefits from participating, such as extra monitoring and appointments, or a feeling of helping others. However, it is important to make your decision based on unbiased information about the trial.

Trusting health professionals was also something young people talked about.


Last reviewed March 2017.


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