What is a Clinical Trial?

A clinical trial is a research study that answers specific health questions. It also adds to medical knowledge. Researchers carefully conduct clinical trials. The goals are to develop and evaluate treatments and interventions that can fight disease and improve health. We also perform observational studies.

Clinical or interventional trials determine whether experimental treatments, such as drugs, devices, and procedures, or new ways of using known therapies are safe and effective under controlled environments that follow strict rules to protect study participants. Clinical trials are conducted in steps called phases. Each phase entails a new study aimed at answering a progressive set of questions:

• Phase I: Is it safe?
• Phase II: Does it work?
• Phase III: Is it better than what we have now?
• Phase IV: What are possible long-term effects?

Observational trials address health issues in large groups of people. They take place in natural settings. For example, researchers may want to learn about the effect of lifestyle on heart health. So, we may observe a group of older adults over time. We may also look at the long-term outcome of participants who have received various treatments during routine clinical care.