What is a clinical trial and why do we need them?
Clinical trials are research studies involving people, which compare a new or different type of treatment with the best treatment currently available (if there is one). Some clinical trials look at possible ways to prevent illnesses, for example by testing new vaccines. No matter how promising a new drug or treatment may appear during tests in a laboratory, it must go through clinical trials before its benefits and risks can be fully understood by doctors and scientists. Trials aim to find out if treatments are safe (what side effects they have), if they work better than the current treatment and the impact they might have on quality of life.
Clinical trials are the most reliable and best way of testing treatments. A new treatment is not always better, and can sometimes be worse than existing treatments. Trials are therefore very important to find out whether one treatment is safer and more effective than another, or sometimes to find out if it is just as good.
What is a randomised controlled trial?
The best way of knowing whether one treatment is better than another is by carrying out a ‘randomised controlled trial’ (RCT). A randomised controlled trial compares two or more groups of people: one or more research groups receive the new ‘research’ treatment(s) and a control group receive the existing ‘standard’ treatment. This allows researchers to see whether a new treatment is better than an existing treatment.
The decision about which treatment each participant in a randomised controlled trial receives is made at random – based on chance, rather than decided by the doctor or participant. This process is called randomisation and is the best way of ensuring that the results of trials are not biased. For example, if a doctor chose which treatment a patient should receive as part of a trial, she or he might unintentionally give the new treatment to sicker patients, or to younger patients. This would make the results of a trial unreliable, as it could exaggerate or hide the effects of the treatment.
Randomisation ensures that the two (or more) groups of people in a trial are as similar as possible, except for the treatment they receive. This is important because it means that researchers can be sure that any differences in outcomes between the groups are therefore only due to the treatment they received.