How clinical trials are approved

All trials go through an approval process. This page tells you about this process and why they need to be approved. There is information on

Peer review

The detailed plan which outlines how the trial will run is called the protocol. This should be reviewed and approved by a group people who are not involved in the trial. When research teams ask another organisation for funding, peer review is often part of the funding approval process.
The peer review group includes doctors, other health care professionals and non medical (lay) members of the public.
They look at things like:
  • the aim of the trial and how important the issue is
  • the design of the trial
  • the patients the research team would like to recruit
  • whether people are likely to want to take part
  • how they plan to analyse the results
  • whether the research team have thought about all the possible issues

Ethical approval

The trial protocol is then reviewed by a Research Ethics Committee, or REC. There are lots of committees up and down the country, and they are organised by the Health Research Authority (HRA).
Each committee has up to 15 members who are not involved with the trial in any way. At least 1 in 3 of these people are members of the public who are not researchers or health professionals.
RECs look after the rights, safety, dignity and well being of those taking part in research in the NHS.  They assess each trial protocol against a set of standards. 
They look at things like:
  • the aim of the trial and how important the issue is for patients
  • how the research team plan to recruit people
  • whether the likely benefits are greater than the possible risks
  • the qualifications and experience of the team running the trial
  • whether it’s been peer reviewed
  • if the patient information sheet (PIS) is complete and easy to understand
  • if extra information such as GP letters, patient questionnaires or forms are well written
The committee then decides if the trial is safe and ethical to do, and whether it can go ahead or not.
The committee can ask the research team to make changes to the protocol or the patient information sheet before they give the final go ahead.

During the trial

The researchers are not allowed to change the protocol without telling the ethics committee. They must also tell the committee if there are any serious unexpected side effects.
The committee can stop the trial at any time if they have any concerns about the welfare of the people taking part.
At the end of the trial, the ethics committee gets a copy of the results.

Other checks

Depending on the trial, the research team may also need to get the go ahead from other groups as well as an ethics committee.
For example, a trial may use scans or treatment that would expose people to more radiation that they would have had otherwise. In this case, the team must get a certificate from a specialist committee to give them permission to do this.

Trial authorisation

All clinical trials of medicines and studies on medical devices also need to be authorised by an organisation called the Medicines and Healthcare Products Regulatory Agency (MHRA). This is called Clinical Trial Authorisation (CTA).

Hospital approval

Each hospital that wants to take part in the trial has to get approval from their NHS Research and Development (R and D) department. You may hear this called site specific assessment (SSA).
This assessment makes sure that the hospital has the staff, time, equipment and expertise to carry out the trial safely.  The R and D department also look at other trials already running at the hospital. They may not want to run two trials recruiting similar patients, for example.
Once the R and D department has given permission for the hospital to run the trial, the trial team will arrange training for the hospital staff. This could be online or in person and should include anyone involved with the trial including doctors, research nurses, pharmacists and radiographers.
Once everyone is familiar with the trial and all the approvals are in place, they can start recruiting patients.

Related information


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Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

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