Understanding Clinical Trials

Armen Hareyan's picture

Clinical trials play a vital role in improving medical care. As new medical treatments are developed, volunteers participating in clinical trials help ensure that treatments are safe and effective.

"A clinical trial is an experiment in which we are trying to determine whether a technology is effective in humans and if so, how effective," says Robert Califf, M.D., professor of medicine at Duke University Medical Center and director of the Duke Clinical Research Institute. "The technology we're assessing may be a diagnostic tool, a drug, a device or a behavioral intervention to improve human health.

"It's an experiment because we have two groups, one that gets the new proposed treatment or diagnostic strategy and the other that gets the standard care that existed before the new proposed strategy existed," Califf continued. "When we do a randomized clinical trial, there is no guarantee which treatment you'll get. It's important that the strategy is allocated randomly, as if it were drawn out of a hat. But it's also important to keep in mind that we only do randomized trials when we don't know which strategy is better."

Califf says clinical trials are typically sponsored either by a government agency, for example the National Institutes of Health (NIH) or by private industry, as when a pharmaceutical company is developing a new medication. He says both types of trials are heavily regulated by the Food and Drug Administration (FDA) and other federal agencies.

Clinical trials are usually described in terms of phases. "A simple way to think about it," explains Califf, "is that Phases I and II are in the period when we have a therapy and we don't yet know much about it. We're still researching how it should be administered and in what dosage. In Phase III, we really put it to the test to find out if it should go on the market and whether it should be available for routine practice. This is usually a larger phase, where the treatment is compared to the current standard of care. In Phase IV, after it's on the market, we still do trials to learn more, maybe a new use or a comparison with another specific treatment that's also on the market for the same condition."

For the most part Phase III and IV trials are now done at multiple sites.

"They're also increasingly done in multiple countries," Califf adds. "Some of the trials we do at Duke involve up to 35 countries. Disease knows no borders."


Califf says informed consent is an important part of a clinical trial, as with any medical procedure. "It's important to understand that this is not simply signing a piece of paper. It should be a dialogue between the person receiving a treatment and the person giving the treatment," he says.

Participants in clinical trials fall into two groups. The first is completely healthy volunteers who want to learn about the biology of a treatment or to help researchers develop improved treatments for a condition. The majority of clinical trials, though, says Califf, involve people who already have an illness or are at high risk for having the illness.

Some clinical trial participants are compensated for their involvement in the study. "When healthy volunteers participate, compensation is considered to be quite reasonable, as long as it's not of an order of magnitude that would entice someone to take a risk. For someone who has an illness, compensation is generally not considered to be a good thing, since having an illness may impair someone's judgment and enticing them with a monetary reward would not be positive," Califf says. "However, there is usually some compensation for those who are ill to come to the clinic, to cover the extra burden of the clinical trial."

Califf suggests people interested in participating in a clinical trial should speak with care providers. All participants should understand the benefits and risks.

Clinical trials can help researchers develop new treatments while participants become more involved in their health care, but Califf believes there's an even better reason to participate.

"The most important reason to participate in a clinical trial is because of a belief that we can make the human condition better," he says. "In fact, in our own patients, when we asked that question, altruism was the No. 1 reason for participating. The bottom line for me is that it's a noble thing to do to advance our knowledge of how to prevent and treat disease."


The source of this article is http://www.dukemednews.org