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Advancing clinical research
Protocols by research type (onsite intramural protocols, fiscal year 2004)
Clinical studies are medical research studies (or protocols) in which human volunteers
participate. Clinical trials are studies developing or investigating new treatments and
medications for diseases and conditions. Natural history studies investigate normal
human biology and the development of a particular disease. Screening studies
determine if individuals may be suitable candidates for inclusion in a particular study.
Training studies provide an opportunity for staff physicians and other healthcare
professionals to follow particular types of patients.
Clinical trials proceed through four phases
Researchers test a new drug or treatment for the first time in a small group (20–80)
of people to evaluate its safety, determine a safe dosage range, and identify side effects.
The study drug or treatment is given to a larger group (100–300) of people to see if
it is effective and to further evaluate its safety.
The study drug or treatment is given to large groups of people (3,000 or more) to
confirm its effectiveness, monitor side effects, compare it with commonly used
treatments, and collect information that will ensure safe usage.
These studies are done after the drug or treatment has been marketed. Researchers
continue to collect information about the effect of the drug or treatment in various
populations and to determine any side effects from long-term use.
Breakdown of clinical trials