What are the phases of clinical trials? A research study involving human volunteers (also called participants) that is intended to add to medical knowledge.Clinical trials are scientific studies using human volunteers that determine the effectiveness, safety and tolerability of an intervention. Each clinical trial has benefits and risks. Before you decide to be in one, you need to have all your questions answered. CROs support pharmaceutical, biotech and medical device companies and research institutions with a wide range of services, including: Clinical Trials Management. VCU Health CMH is proud to be included in the breakthrough studies made available to residents of southern Virginia and northern North Carolina. Practical Clinical trials: increasing the value of clinical research for decision making in clinical and health policy. JAMA, 2003 Sep 24; 290(12):1624-32. In randomized controlled trials (randomized clinical trials), researchers divide people into groups to compare different treatments or other interventions.