Clinical Trials

A clinical trial is a prospective biomedical or behavioral research study of human subjects that is designed to answer specific questions about four (4) types of biomedical or behavioral interventions.  ​

  • Drugs
  • Treatments
  • Devices
  • New ways of using existing drugs, treatments, or devices

Clinical trials are used to determine whether new biomedical or behavioral interventions are safe, efficacious, and effective. 

Biomedical clinical trials of an experimental drug, treatment, device, or behavioral intervention may proceed through four (4) phases:

  • Phase I: tests a biomedical or behavioral intervention in a small group of people (e.g. 20-80) for the first time to determine efficacy and evaluate safety (e.g. to determine a safe dosage range and to identify side effects)
  • Phase II: tests a biomedical or behavioral intervention in a large group of people (e.g. several hundred) to determine efficacy and further evaluate safety
  • Phase III: tests a biomedical or behavioral intervention in a larger group of people (e.g. several hundred to several thousand) to determine efficacy by comparing the new intervention to other standard or experimental interventions, as well as monitoring adverse effects and collecting information that will allow the intervention to be used safely 
  • Phase IV: monitors the effectiveness of the approved intervention in the general population after the intervention has been marketed and collects information about any adverse effects associated with widespread use 

The Vanderbilt Clinical Trials Center offers resources and advice to both new and experienced researchers. Visit their website here.