Clinical trials are research studies involving patients.

Clinical trials compare a new or different type of treatment with the best treatment currently available (if there is one).

The MRC Clinical Trials Unit runs trials in a range of disease areas. We specialise in trials in cancer and in infectious diseases, such as HIV and tuberculosis. We also run trials in other areas. Most of the trials we run are randomised controlled trials.

The following pages give more information about clinical trials, particularly randomised controlled trials.

What is a Clinical Trial?

Clinical trials are research studies involving patients, which compare a new or different type of treatment with the best treatment currently available.

What is a randomised clinical trial?

In an RCT, two or more groups of people are compared: one (or more) experimental group(s) who receive a new treatment, and a control group, who receive the current standard treatment.

What is an observational study?

Observational studies are a fundamental part of epidemiological research.

How do we make sure a trial is safe?

A lot of care is taken to ensure that clinical trials are as safe as possible. This short film explores some of the ways we make sure our trials are safe.

How is a trial designed and run?

Questions about health care which lead to trials can come from patients, people working in the NHS, researchers, organisations that fund research, drug companies or policymakers.

What happens at the end of a trial?

At the end of a trial, all of the information that has been gathered together during the trial is analysed.