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Clinical trials are research studies that are used to test and evaluate potential medical advances. Before a new medication, surgical procedure, medical device or other potential advance can be used in the general population, it has to go through a rigorous series of clinical trials. These trials will determine if it's safe and effective at meeting its medical objectives.

When a medical advance is being developed, often the work will begin in a laboratory and then move to animal testing. Once the advance is deemed safe enough to test in humans, researchers are often looking for volunteers to participate in clinical trials. These clinical trials are carefully regulated for safety, and a number of them must be successfully completed before a medical advance can be approved.

Types of Clinical Trials

There are several types of clinical trials. When a new drug or surgical procedure is being tested, this is known as a treatment trial. There are also screening and diagnostic trials, which examine potentially new and better ways to detect or diagnose medical conditions. Prevention trials examine methods for preventing illness, and quality-of-life trials look at methods for improving the lives of people with chronic illness. A natural history study often takes a “big picture” look at the progression of a particular disease in the population.

In addition to the different types, clinical trials also have different phases. There are four phases in all, and a medical advance must make it through Phase I, Phase II and Phase III before it can be approved. Each phase involves larger studies with more participants to determine its safety and effectiveness. Once an advance reaches Phase IV, it is approved but still monitored for safety and effectiveness during its sale and use.

Risks and Benefits of Clinical Trial Participation

Clinical trials are carefully monitored for safety, but there are still some risks for individuals who participate in them. Side effects and complications may still occur from the medications and treatments being tested. However, participants also may receive a cutting edge treatment or procedure to help with their medical condition before it reaches the general population. People who are considering participation in a clinical trial need to weigh the potential risks and benefits carefully before agreeing to take part.

SOURCES: U.S. National Institutes of Health

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