How the process works in practice
If you’re thinking of taking part in a research study, you’ll be wondering how studies are designed so you know what's involved.
All studies are designed differently depending on what is being researched.
This page explains the process around most clinical studies and what you can expect before, during and after. Other research studies such as surveys, may be organised differently.
Giving your informed consent
Before you take part in a study, a doctor or other researcher should make sure you have given your informed consent. Before you can do this, you will need to understand the purpose of the trial and what taking part will involve, including the main risks and benefits .
You'll need to know how the trial might affect you before you can give your consent. We've provided a helpful list of questions.
New treatments, or new uses for existing treatments, are tested in various stages – also known as "phases". This helps establish what becomes a new medicine and what doesn’t.
Before being given to people for the first time, all drugs are checked for safety in animals.
- Phase 1 involves a relatively small number of people.
- Phase 2 is used to find out whether a drug works, whether it’s safe and what the side effects are.
- Phases 3 and 4 involve larger numbers of people and are designed to assess how the treatment works, compared with existing treatments, while continuing to assess side effects and risks.
New treatments versus standard treatments
Not everyone receives a new treatment in a clinical trial. Sometimes trials need to compare a new treatment with the standard treatment already in use, if there is one.
- Some people in a trial will receive the standard treatment but, until the results of the trial are analysed, no one will know which treatment is better.
- New does not always mean better, so you are not always worse off if you don’t receive a new treatment.
Using a placebo
A placebo is a medicine or a treatment that looks exactly the same as the medicine/treatment being tested, but is designed to have no effect at all.
We can be biaised without realising it, as sometimes we believe we feel better because we’ve taken something we think will make us feel better. This is known as the placebo effect. You can find other common terms in our glossary.
There are many different ways to design a study, depending on what’s being tested. The researchers always want to get the most reliable results as possible, but sometimes the type of medicine or side effects cannot be disguised and therefore blind trials are not always possible.
In ‘randomised’ trials, you’ll be allocated to one or more groups. You’ll be allocated at random, usually with the help of a computer program. You might be in the control group. Researchers run these trials as they give reliable results.
People in the control group are not given any treatment at all. You’re still a very important part of the trial: the results from this group are needed to compare with the results of the test treatment.
Don't forget, the treatment being tested may be no better than the control, which is why the trial needs to be done.
Blind trials are important because they offer reliable results. Researchers design blind trials because if you knew which treatment you were getting, it could influence how you feel, or how you report your symptoms.
It’s not always possible to have a blind trial, as the treatment being tested might be too obvious. In a blind trial the treatments need to look exactly the same.
In a blind trial, researchers won’t tell you which which treatment you are getting. You could be getting the new treatment. Or you could get a standard treatment or a placebo. You will be monitored in the same way, no matter what you’ve been given.
Double blind trials give a very neutral outcome when it comes to results. You can only have a double blind trial when both the treatment and the effects aren’t very obvious.
In a double blind trial, neither you or the researchers know which treatment you're receiving. You will be allocated a number at random. Sometimes this is done by a computer. These numbers are also allocated to the treatment and this is kept secret until the end of the trial.
Regular tests and side effects
Once you’re in a trial, the researchers will want to carry out regular tests to find out how your treatment is working and lookout for any side effects – so will ask questions about any new symptoms, including psychological symptoms.
The type and frequency of the tests may vary according to the research you’re taking part in so be sure to ask what’s involved.
You may also be asked to fill out questionnaires or keep a diary. This might mean going to your hospital or GP more often, so bear this in mind before you agree to take part.
Support for you and your family
Researchers will also look at the wider effects of a treatment on your life as a whole – in other words, your ‘quality of life’. So they may ask if you can take part in your usual day-to-day activities, or if you need any extra help around the home or to look after your family.
How will trial results be used?
At the end of a trial, the results should be made available to everyone who took part if they want them. Researchers should publish the results, regardless of what they show, and also demonstrate how the results add to available knowledge.
The Department of Health and Social Care/National Institute for Health Research insists on publication of the results of all research studies that it funds. At NIHR, we publish the results of all the research we fund in our Journals Library.
Because some studies can run for many years, it may be some time before the results are known.
Continuing your treatment
If you are having a new treatment as part of a trial, you might naturally want to continue that treatment after the trial ends. But in practice, it may not always be possible for you to do this.
It may be some time before a new treatment is provided by the NHS or in some cases new treatments are not made available on the NHS. In this case, you will be given the standard treatment for the condition you have.
In some circumstances you may be able to buy the new treatment on a private basis; for example, if the drug has a licence, but is not available on the NHS.
How is it decided whether to make a treatment available?
The National Institute for Health and Care Excellence (NICE) is a public body and part of its role is to recommend whether the NHS should buy new and existing treatments.
It makes these decisions based on how well a treatment works and if it represents value for money. Sometimes, treatment costs only become entirely clear after a trial.
It is impossible to be certain, when a trial starts, about whether or not the test drug or device will be made available on the NHS following the drug trial or research study.
Patients can get involved with NICE's work.
Regulation around research is tight. The rules are there to ensure that every phase of a trial or study is run safely. Read more about how trials are regulated, approved and funded in the UK.