Clinical trials & medical research

Different types of trials

Clinical trials cover a broad range of different types of research and are carried out in a number of stages - see our introductory explanation in ‘Why do we have clinical trials in children and young people?’ Here we focus on the different types of treatments and interventions which can be involved. 

Examples of how clinical trials can help:

Prevent illness by testing a vaccine

Detect or diagnose illnesses by testing a scan or blood test

Treat illness by testing a new medicine

Find out how best to provide psychological support

Find out how people can control symptoms or improve their quality of life by testing how a particular diet affects a condition

Preventive trials' look for better ways to prevent disease in people who have never had the disease or to prevent a disease from returning. These approaches may include medicines, vitamins, vaccines, minerals, or lifestyle changes.

Sophie, aged 23, explained why she wanted to take part in a research to help prevent the onset of diabetes in people with cystic fibrosis. Ruby and Joanna talked about taking part in trials to find the best treatment to help prevent thinning of bones in people who take steroids. 

Both Will and Buddy took part in vaccine trials. Will took part in a swine flu vaccine trial and says “They were just seeing which one was the best on that they could use out on the public and stuff.” Buddy took part in a meningitis C vaccine trial and says' “It wasn’t really too bad. Because she came and talked to me about like what she was doing and it didn’t hurt. I had one vaccination and they took some blood”.

Drug trials' may be testing whether a new drug has any major side effects, or whether it works better than an existing treatment; but they may also test timing (when or how often to give a drug) or dosage (how much of the drug is needed to be effective). Drug trials are probably the most familiar type of trial to many people. Trials can also be used to test whether giving a treatment in a different way will make it more effective or reduce any side effects.

Lois is taking part in a randomised trial on improving the treatment for Grave’s disease, which usually affects women but is rare in teenage girls and even rarer in males. Grave’s disease means that Lois has an overactive thyroid gland and she has to take daily medication to help control it. 

Graham is taking part in a clinical trial on the treatment of children and young people with Hodgkin’s lymphoma. Graham was unsure of the purpose of the trial but understood that it was to find out if treatment is just as successful by replacing one drug with another drug that is less likely to cause infertility or early menopause, and to find out what the long term effects are of each drug on fertility.

Not all randomised trials are drug trials. They may also be testing other types of care, such as different levels of monitoring, the effect of different types of diet, or the effectiveness of different forms of screening e.g. 

Screening trials: detect or diagnose illnesses, for example, by using a scan or blood test.

Diagnostic trials: conducted to find better tests or procedures for diagnosing a particular disease or condition.

There is also growing interest in testing different ways of giving people health information, to see which is most helpful to them in making decisions or understanding and managing their condition. 

Information and quality of life interventions' to help people learn about their condition and help them to self-manage their health better and improve comfort and quality of life. Interventions may include finding the best approaches to help people control their symptoms or improve their quality of life by testing how a particular diet affects a condition. 

Other types of trials can include those that find the best surgical interventions and trials which compare the frequency or intensity of a treatment, such as radiotherapy regimens and even Psychological therapies' which help to find out how best to provide psychological support.

Some young people we interviewed were invited to take part in non-randomised trials - see ‘Other types of medical research’. These types of trials are also important in improving treatments and advancing knowledge.

Last reviewed March 2017.
Last updated July 2014.


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