Understanding Clinical Trials
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
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
"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
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
"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