IN THIS ISSUE

From the Spring 2004 Issue

Learning Center

What Are Clinical Studies?

Clinical studies, or trials, are often in the news. Reports about these studies may tell how a treatment can help patients. But they do not often explain why we can trust the results of these studies. We do not hear about how the study was done or how it proved that the treatment works. In this article, we'll look at how a clinical study is done and what the process means to you.

A clinical study is an essential part of medical science. Clinical studies are a major part of the work of Guidant and other healthcare companies and organizations. Without these studies, we could not find out how well treatments work, or if they are safe. And we would not know which treatments are the most helpful to patients.

Researchers know how to set up a study to get accurate results. The goal of most studies is to answer the question, "Is treatment 'A' better than treatment 'B'?" A new treatment is often tested against the current treatment. If the new treatment shows that it works as well, or better, more doctors may begin to use this new therapy with their patients.

One example is the Multicenter Automatic Defibrillator Implantation Trial II (MADIT II). In this study, one group of patients was given heart medicines and implanted defibrillators. Another group was given only heart medicines. Then the results of the two groups were compared.

This study showed that some heart patients can be helped even more when a defibrillator is added. At one time, most heart patients were treated with only medicine. Today, defibrillators are a big part of treating certain heart patients.

How Is a Study Designed?

First, standards are created to decide if someone can or cannot take part in a study. Standards include age, gender, the type and stage of a disease, previous treatment history, and other medical conditions. These rules are used to identify the right participants. All of this helps to create a consistent group of patients.

Once standards are defined, there are many other components of study design that help to provide accurate results that apply to other patients. Here are some of the important factors:

• Randomization: Assigning people to a treatment group by chance. It is almost as if the researchers flipped a coin so that no patient has a better chance of getting the treatment than another patient. In this design, individual characteristics are less likely to make the results inaccurate.
• Controlled study: A study in which one group receives either no treatment or the currently available treatment. This group is called the control group. The control group is compared with the test group. The test group is the group that receives the treatment that is being tested. The use of these two groups helps to ensure that conclusions can be made about the safety and effectiveness of one treatment versus the other.
• Sample size: The number of patients who participate. It is good to have a large group of people in the study. A large sample size makes it less likely that a few patients will impact the results.
• Multiple test sites: Doing the same study in more than one place. Doing the study in several places helps to ensure that a test group is diverse enough to represent most people around the country. For example, participants for the study will be from different cities and/or states. This helps make sure that location does not influence results.
• End point: The overall outcome that a study is set up to evaluate. When the end point is met, the study is considered to be complete.

After the study is completed, the results will be sent to the Food and Drug Administration (FDA) for review. The whole process—from beginning to end—can take several years.

Clinical Studies Help Create Better Methods of Care

Carefully conducting clinical studies is one of the best ways to find new, safe, and effective treatments. If the outcome of the study stands up to a review by doctors, the study may be published in a medical journal. Medical journals are a good way for many doctors to learn about new devices or therapies. Reading about clinical studies, and having confidence in the outcomes, provides doctors with new options to treat their patients.

The federal government helps to monitor clinical studies. Interested in learning more about clinical studies? Think you might be a good candidate for one? Visit the US federal government website to learn more.

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