What is a randomised trial? - video transcript

A randomised trial is a way of testing new treatments without bias.

Doctor Brown developed a new cancer treatment that she thinks is as good if not better that the current treatment.

To find out if it is better she needs to test it.

The new treatment is called treatment A and the current treatment, treatment B.

She asks people with cancer to take part in a trial to compare the treatments and gives one group the new treatment and the other the current treatment.

To make sure there is no bias the groups need to be as similar as possible. So the groups need to have a similar age range of people, they need to have similar general health and to have had similar treatments.

If the two groups are too different it might affect the results. Also, neither Doctor Brown nor the patients choose which treatment they have.

If Doctor Brown chose she may subconsciously put the sicker patients into the current treatment group and give the new treatment to the fitter people making the new treatment look as if it worked better, when it really didn’t.

So to prevent bias Doctor Brown puts the details the details of those taking part into a special computer programme and that randomly allocates them to either treatment A or treatment B.

This means that the people taking part in the trial have treatments that are suitable for them and that will help the doctor to find out if the new treatment works better than the current one.