clinical trial A clinical trial to evaluate the efficacy of a new drug. An interventional study that contains a set of procedures in medical research and drug development that are conducted to allow safety (or more specifically, information about adverse drug reactions and adverse effects of other treatments) and efficacy data to be collected for health interventions (e.g., drugs, diagnostics, devices, therapy protocols) that is performed over phases. PERSON: Nicole Vasilevsky http://en.wikipedia.org/wiki/Clinical_trial investigation human study subject group metadata complete