Office of
Research

College of Human Medicine

Clinical Trials

What are Clinical Trials

Clinical trials are designed to determine whether new or current interventions are both safe and effective for changing outcomes in humans. They use existing knowledge gained from basic research or practical experience for the purpose of creating new or improved products, processes, or practices.

There are different types of clinical trials, although they all generally utilize randomized selection and a control group (RCT). Types include: treatment trials, which test new treatments, new combinations of drugs, or new approaches to surgery; prevention trials, which look for better ways to prevent disease in people who have never had the disease or to prevent a disease from returning; screening trials, which test the best way to detect certain diseases or health conditions; and, quality of life trials, which explore ways to improve comfort and the quality of life for individuals with a chronic or terminal illness.

Clinical trials are conducted in four phases, which are:

  • In Phase I trials, researchers test a new drug or treatment in a small group of people (20-80) for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
  • In Phase II trials, the study drug or treatment is given to a larger group of people (100-300) to see if it is effective and to further evaluate its safety.
  • In Phase III trials, the study drug or treatment is given to large groups of people (1,000-3,000) to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
  • In Phase IV trials, post-marketing studies delineate additional information including the drug's risks, benefits, and optimal use.