Introduction
Before being used in practice, new treatments must be very carefully tested so that the effects on patients can be more fully understood. Clinical trials using volunteers are the best way to assess whether new treatments are safe, what the side effects could be and if they are more effective than exisiting treatments.
Clinical trials show the risks and benefits of interventions and treatments such as surgery, medicines or radiotherapy by comparing them with the current standard treatment or a dummy drug ie a 'placebo'. The treatments are given to patients or healthy volunteers and the researchers then observe and record any differences in their effects over time.
Most clinical trials are randomised controlled trials (RCTs). These are designed to compare two or more treatments as fairly as possible, by allocating different treatments to participants on a random basis to reduce the likelihood of bias in a trial.
Stages of a clinical trial
Phase I: this stage involves a small number of participants (usually healthy) to evaluate how a new drug should be given and at what dose.
Phase II: the researchers continue to test the safety and acceptability of the drug and begin to assess whether it works on people with the condition it is designed to treat.
Phase III: at this stage the new drug/combination of drugs is compared with the current standard treatment on a random basis. This is to ensure that the trial results reveal the differences between the treatments given rather than the differences between the people recieving them. Phase III trials often involve large number sof volunteers and may be conducted at doctors surgeries, hospitals and centres throughout the country.
Phase IV: This tests the long term effects of a tretament, sometimes after it has been introduced as a standard practice.
Safety of a Clinical Trial
Clinical trials generally take place once extensive laboratory testing has shown that any new treatments being assessed are safe. In the UK, researchers must obtain approval from the Medicines and Healthcare products Regularory Agency before a trial can start. They must draw up a plan called a protocol, which includes information such as who and how many people will take part, what question the trial aims to answer, what treatments will be compared and how the test results will be collected.
All trial protocols are assessed for scientific merit by independent experts and approved by an ethics committee to ensure that the rights of the participants are respected. One this protocol has been approved, the trial can begin.
Participants can withdraw from a trial at any stage without having to give a reason. This will have no effect on the care they receive.
Taking Part in a Clinical Trial
The people who volunteer to take part in a clinical trial play an essential role in helping researchers to develop and test treatments for the benefit of the community. If you are being treated for a condition, as your doctor or health care professional who sees you the most often if they know of any trials that may be suitable for you.
Eligibility
All trials have guidelines about who can or cannot take part called inclusion/exclusion criteria. The researchers use these criteria when recruting volunteers. You will be asked details of your medical history and given a thorough medical examination. You will also be asked to sign a consent form. Volunteers have the right to withdraw from a trial at any time.
