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What are clinical trials?

Clinical trials are research projects that test new medical approaches. They often try to find out the best ways to treat, diagnose, or prevent diseases or medical conditions.

A clinical trial might want to find out if one treatment (such as a drug, or a procedure) works better than another, or when or how a treatment should be given. For example…

  • Is it better to give a baby a lumbar puncture procedure with them sitting up or lying down?
  • If a pregnant woman has pre-eclampsia, is it better for her baby if she gives birth sooner or later?
  • Does giving a premature baby a nutritional supplement help their brain development?

Researchers work hard to design trials to make sure that they collect the information needed to answer their main question. This includes talking to people that have had the condition before, and their families, in order to find out what they think it is most important for the trial to focus on.

What is a randomised controlled trial?

A randomised controlled trial compares two or more types of treatment or procedure to see which works best.

They are thought to be the best type of research study (the “gold standard”). This is because the people taking part in them are randomly put into the different treatment groups (using a computer):

It is very important that the groups are as similar as they can be to make the comparison fair in order to understand the effect of a treatment and see if it really makes a difference. Therefore, people cannot choose their group and neither can their doctor. If people could choose, some sorts of people may be more likely to choose one of the groups instead of the other.

Randomly putting people into groups helps to remove any bias, so that we can really understand if a treatment makes a difference.

The NPEU Clinical Trials Unit tends to run large randomised controlled trials, often with hundreds or thousands of babies and parents taking part.

What happens in a randomised controlled trial?

After being randomly put in a treatment group …

… the person starts receiving the treatment …

… and the researchers collect data about them. This can be from medical records, laboratory reports, or questionnaires participants complete at home.

At the end of the study, when the researchers have collected all the data …

… they will analyse it. This is to see whether there is a difference between the treatment groups, and how likely it is that any difference is real (caused by the treatment rather than by chance).

Then the results are written up and published in a medical journal.

What is a blinded trial?

Randomised controlled trials are often blinded. This means that the people taking part do not know which treatment group they are in:

In a double-blinded trial, the person’s doctor does not know which group they are in, either. This is so that they do not treat the person differently depending on which group they are in.

Everyone in the trial gets medicine that LOOKS the same.

In some blinded trials, one group is given the medicine, and the other something that looks like the medicine but does not contain any of it (a placebo).

If people knew which medicine they were taking, it might affect how well they think they are feeling or what they choose to do. So the two groups could end up behaving in different ways or answering questions differently. This would make the comparison unfair.

Why are clinical trials important?

Because if a trial shows that a treatment seems to work, doctors should know this so that they can offer it to everyone who needs it.

Because randomised controlled trials usually provide the best evidence as to whether a treatment works or not.

Because doctors want to know how likely it is that the medicine or treatment they give to someone will work.

Because they play a key role in advancing medicines and improving healthcare!

Because if a trial shows that a treatment does not help, people can stop using it.

Randomised controlled trials are only possible if people take part. The more people of all different backgrounds that take part in clinical trials, the more sure everyone can be that the medicines and treatments their doctors use work well for everyone, and that they are receiving the treatments that are best for their condition.

If you would like to learn more about randomised controlled trials, or have any questions about the trials that the NPEU runs, please do get in touch: