A clinical trial is a biomedical or health-related research study on human subjects that follows a pre-defined protocol or plan.
There are different types of clinical trials:
Participation in a clinical trial is voluntary, and the volunteer does not have to be sick to join a study; many studies include people who don’t have a certain condition, as well as those who have it.
The research plan is carefully explained to those who volunteer before they agree to participate.
All clinical trials have guidelines about who can participate, using criteria that help to produce reliable results. The factors that allow someone to participate in a clinical trial are called “inclusion criteria” and those that disallow someone from participating are called “exclusion criteria.” These criteria are based on factors such as age, gender, the type and stage of a disease, previous treatment history, and other medical conditions.
It is important to note that inclusion and exclusion criteria are not used to reject people for personal reasons. Instead, the criteria are used to identify appropriate participants and keep them safe. The criteria help to ensure that researchers will be able to answer the questions they plan to study.
For more information on clinical trials, visit clinicaltrials.gov, a service of the National Institutes of Health.