Clinical trials internet resource
Board of Science and Education
November 2004
Introduction
Clinical trials are studies that analyse potential and actual treatments of medical and psychological conditions on affected people to see if they provide an effective remedy. They also permit a comparison of treatments to ascertain their value. Although clinical trials often test the effects of drugs, they also test medical devices, and other forms of prevention and treatment, such as health promotion, methods of disease detection, surgery and physical therapies.
Clinical trials are vital for reliable information about the effects of different treatments, ensuring that treatment options are effective and safe. The results of controlled trials help to develop a sound evidence base, which doctors and patients can use when making treatment decisions. In offering a reliable evidence base, doctors can be more confident that they are using treatments that have been shown to have beneficial effects and that resources can be allocated to effective therapies.
Randomised clinical trials (RCTs) consist of two or more comparison groups (known as treatment or experimental groups), receiving either the treatment being studied, or the standard treatment or placebo (known as the control group). Random assignment, the highest standard for experiments, of participants reduces threats to internal validity by randomly assigning participants to either the treatment or control group. In some instances, cluster randomisation methods are used where patients are allocated to a treatment by group rather than on an individual basis (e.g. by clinic, by town). Statistics should accurately represent the sample.
This resource, for medical and health professionals, seeks to provide a short guide to improve general knowledge of clinical trials, including the process by which they are developed. It addresses some of the issues affecting such trials, particularly issues of both doctor and patient participation. While not exhaustive, the resource does provide links to external resources throughout. Individuals who are considering participation in a clinical trial should visit our public health page, which provides information on current clinical trials.