Clinical trials test whether different medical drugs, devices and medical treatments are safe and how well they work. Some of them involve healthy members of the public and others may involve patients undergoing treatment and who want to take part.
Clinical trials are aimed at answering certain health questions such as how to prevent an illness, treat an illness to increase chances of survival, or to improve the quality of life for those living with an illness.
Each trial is carefully planned, detailing factors such as who is eligible to participate, the schedule of procedures, length of study, information to collect and results to measure.
Why are clinical trials important?
Clinical trials provide the best way to compare approaches on how to prevent and treat health problems. Health professionals and patients need the evidence from the trials to know what works best. For example, if a certain treatment has serious side effects, it may not be worth proceeding with development.
How are trials set up?
In clinical trials, doctors, nurses, researchers and patients work together with trial managers, statisticians and others. A trial protocol is set up and this is sent to an ethics committee for approval.
The committee will check factors such as whether participants are recruited in an appropriate manner and if the information given to them to decide whether to participate is clear and satisfactory.
Who can take part?
Every trial has guidelines about who can take part. Eligibility criteria ensure that trials include people who may benefit from the treatment and make sure that those involved are not exposed to unnecessary risks.
Some trials only include people of one sex, those in a particular age group or those at a particular stage of an illness. Clinical studies for children, for example, are essential to develop therapies and interventions specific to children.
All participants have to sign an ‘informed consent’ because some risks may be unavoidable, however well they are controlled and monitored. Participants usually have their medical record reviewed and undergo a physical assessment.
What are the risks and benefits of clinical trials?
Clinical trials have to be carefully designed to maximize benefits and minimize risks. Some drugs are tested on animals before they’re tested on humans. The researchers must make potential participants aware of any possible risks and side effects so they can make informed decisions about whether to take part.
Participants are carefully monitored during and after the trial. They may be asked to fill out a questionnaire or keep a diary and have to undergo regular tests. This may be an inconvenience but the benefit is that testing will pick up any changes in health, even if this is not related to treatment.
All trials are checked and monitored to make sure that the people who take part are protected. Each trial has a sponsor responsible for how it is conducted, such as the institution hosting the research (a university, for example) or an organization funding the trial.
Early-stage trials usually involve healthy people or a small number of patients and later stage trials include large numbers of participants. For example, in the development of new drugs, phase one trials involve testing small groups of participants to find out the safety of the drug.
In phase two, the drug will be tested on larger groups to better measure safety and side effects. Phase three includes hundreds or even thousands of people and compares the effects of newer drugs with standard treatments. Phase four trials are only carried out after a drug is shown to work and is licensed.