Clinical trials or research studies compare new treatments with old ones or changes in the way treatments are given. Trials are carefully designed to minimise risk and make sure that no harm can come to patients. There is a very rigorous process to make sure that this happens and that only the most worthwhile and best designed trails can recruit NHS patients.
There is a lot of consultation and discussion before a patient is entered into a trial and patients can withdraw from a clinical trial at any time.
Patients can only enter trials if they meet the right criteria – if all of the clinical conditions meet the trial protocol. Many patients are not suitable for trials for different reasons – e.g. previous treatment, stage of disease.
You can find out more about clinical trials in the UK here: UK Clinical Trials Gateway.