Do all clinical trials test drug therapies?
There are two main types of clinical trials: interventional and observational. Interventional trials determine whether experimental treatments or new ways of using known therapies are safe and effective. These trials might ask a participant to take an experimental new drug or undergo surgery. Observational trials address health issues in large groups of people or populations in natural settings. Participants in these trials may be asked to answer questions about their family histories or give blood samples, but they do not receive treatment for their disease. Some observational trials are even open to healthy volunteers.
