Randomised controlled trials

A clinical trial is a medical study involving patients who volunteer to take part. Clinical trials are used in all areas of medicine and are carried out for many different reasons. They could be testing a new treatment by comparing it to the best current treatment available or they could be used in testing new technology or procedures.

From clinical trials we can find out if a new treatment is safe, if it is better than the current treatment and we can find out what the side-effects of the treatment are.

Types of studies

Treatment Trial
There are many different types of trials. The most common type of trial is a treatment trial. These look at the best way to treat a medical problem. They usually involve testing new drugs, new combinations of drugs or new ways of giving treatments.

Quality of Life Studies
These studies look at how a disease and/or treatments can affect your daily life. Many large treatment studies also include a quality of life study. Quality of life data is sometimes called Patient Reported data.


When we do not know which way of treating patients is best, we need to make a comparison. An important part of making a fair comparison is “randomisation”. Most large trials are randomised. Patients taking part are randomly allocated either the standard treatment or the research treatment. This process is essential to avoid bias: if the groups of men receiving each treatment are the same, any differences in the results can only be down to the treatments. Therefore, randomisation means that the results are more reliable. The process of randomisation is usually carried out by a computer-based system.

Should I take part in a trial?

Like any decision you make, deciding to take part in a clinical trial needs to be made as an informed decision based on the evidence made available to you by your doctor. There are both benefits and risks to taking part in a clinical trial so you should take your time in making the decision and consider some of the points below.

The possible benefits of being in a trial include:

  • getting a new treatment that might work well and that you could not get outside the trial. However new isn’t always better!
  • helping to improve cancer treatment for future men like you
  • having more tests, scans or check-ups which you may find reassuring

To weigh against these benefits, there are also risks:

  • a new treatment may have side-effects that are not yet known about. You would be closely monitored and your study treatment would be stopped if necessary. It is important to remember that treatments have been very carefully researched in the laboratory before being given to patients and there is a lot more known about treatments in phase III trials than in phase I and II trials. Studies also have to be approved by an independent Research Ethics Committee
  • some people also find that they have to make more trips to the hospital which can be inconvenient
  • there is a chance that you could be asked to complete some paperwork, such as quality of life forms. These are really useful for the research but may be burdensome to complete

Will I be asked to join a trial?

You may be approached by your doctor about the possibility of participating in several different clinical trials. You should make sure the trial is suitable for you.

RADICALS is a randomised clinical trial that has been designed for men who have had a radical prostatectomy.


MRC Clinical Trials Unit at UCL
Institute of Clinical Trials & Methodology
90 High Holborn
2nd Floor

Email. mrcctu.radicals@ucl.ac.uk