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The Stages of a Clinical Trial

There are many different possible interventions, questions, and ways in which a clinical trial can be designed. However, there are some fundamental stages of a clinical trial. Click on each of the headings below to find out more.

1. Developing a Research Idea

The first step in a clinical trial is identifying the question we want to answer. The question we answer normally represents something which is unknown about a health or treatments. It could be about how long patients live with a new medicine compared to what is currently used or whether different types of care improves people’s lives. Suggestions for potential questions come from a number of different people. For example, patients, carers, health or social care professionals, or health charities.
2. Grant Application

Once we have a question we would like to answer with a clinical trial, we need to money to run it. There are several different ways a clinical trial can be funded. Some of these ways are described on the Who funds trials? page.
We write a grant application to secure funds for each trial. A grant application is a detailed document which sets out what question we want to answer, how we will answer that question, why the research is needed and how much the research will cost.
Developing a grant application is a very collaborate process involving all the different people who work on trials. This includes talking to patients who have real life experience of the research topic. This is called Patient and Public Involvement. You can find out more about this on the Patients and the Public page.
3. Protocol Development

Once a trial is funded the different people who work on a trial (see Who works on trials?) come together to write the protocol. The protocol is essentially a detailed instruction manual for how the research should be run and how people who take part in the trial should be treated.
4. Regulatory Approvals

There are lots of checks in place to ensure that trials are safe and that the people who take part are treated well. The trial protocol is submitted to NHS Research and Ethics Committees (REC), the Health Regulatory Authority (HRA) and the Medicines and Health Regulatory Authority (MHRA – but only if the trial testing drugs or medical devices)for review. we cannot start until we get their approval. If we want to change the way we run a trial, we have to go back to those committees to get permission.
5. Site Set-up

Once all the approvals are in place, the clinical trial needs places (sites) to find trial participants. The sites we use depend on the question being asked. For example, we may work with hospitals, care homes or GP surgeries. El. Once everything is in place the site will get the go ahead to start approaching people to take part (e.g. patients, care home residents etc)
6. Recruitment (Information and Consent)

Once a site is open it can start asking people if they want to join the trial. Firstly, a potential participant is given information about what will happen if they take part. This is called the patient information sheet. They can then decide if they want to take part in the clinical trial, this is called informed consent.
If the person gives consent, site staff then check that they meet all the rules required to take part in the trial. The rules are needed to make sure that only people who are relevant to the question we’re trying to answer are included in the trial. The rules also make sure it’s safe for people to take part. These rules are called eligibility criteria.
7. Randomisation

If the clinical trial is comparing two or more different interventions, trial participants need to be assigned to one. To make sure that this is fair, no one chooses which intervention they receive. Instead, it is done using something called randomisation. Randomisation uses a computer to pick an intervention for each person.
8. Intervention

Trial participants then receive their intervention. We carefully check on everyone when they are receiving their intervention. For example, a clinical trial which is testing a new medicine will review the side effects being reported by patients on a regular basis, with a group of independent experts. Trial participants will always be in contact with a healthcare professional. Participants can stop the trial at any point.

9. Data Collections and Results

So that we can answer the trial questions, we collect information from the people taking part. The type of information we collect will depend on the questions we are trying to answer. We collect that information in different ways. For example, questionnaires about how people are feeling, blood tests, scans, or information from people’s health records. At the end of the clinical trial, we look to see if the information from people having the new intervention, is different to people having the old intervention. We use this comparison to answer our question. We share the answer to our question with other researchers, healthcare professionals, trial participants and the public. The answers are shared through presentations, scientific journal articles and sometimes in the media too.

More Information

For International Clinical Trials Day in 2019 the CTRU posted some videos on some of the different stages of a trial on twitter. Check them out here: