Last updated: Fri, Jun 30, 2017
A clinical trial is an experiment that occurs in a medical setting, that is, a clinic or hospital. They can be roughly broken down into explanatory trials, which answer questions about the causes of a disease or modes of treatment, and pragmatic trials, which look for answers to questions about how to treat conditions in real medical settings.
Clinical trials are generally expensive, since they involve real patients and doctors. The clinical trial of a drug or item of medical equipment is the last step in a long development and testing process. The trial must “succeed,” in the sense of proving the superiority of the new treatment or drug, before the new treatment will be approved and adopted for routine use. Such trials must follow established protocols and standards, and are subject to regulatory review. Because they are expensive, they generally won't be conducted unless they hold promise of a future stream of income.