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One of the greatest advances in medicine
was the introduction of a new research technique in the mid-1950s
called the controlled clinical trial, which is used to determine
if new drugs and other treatments are safe and effective. In the
controlled clinical trial, one group of patients, the treatment
group, receives the new drug or new treatment. Another group, the
control group, is given an inactive pill (a placebo) or the best
standard treatment. Researchers then compare the two groups over
a period of time. The data collected is put through rigorous statistical
techniques to determine whether the new treatment is safer and more
effective than standard therapy or no treatment.
Most clinical trials are conducted on a blind or double-blind basis.
In a blind trial, patients do not know whether they receive the
new drug or a placebo. In a double-blind trial, neither patients
nor physicians know who is receiving the new treatment. This secrecy
is important because patients who know they are taking a powerful
new drug may expect to feel better and report improvement to doctors.
Researchers who know that a patient is receiving the test treatment
may also see improvements that really do not exist.
Clinical trials usually are randomized. Researchers
put patients into the treatment group or control group at random.
This helps to assure that neither group contains an excess of patients
with severe disease. A drug may appear more effective if the treatment
group were packed with patients who had only mild symptoms.
The results of clinical trials are subjected to peer review. Researchers
publish their results in scientific journals or present them to
an audience of other scientists, who are their peers. This gives
scientists not involved in the research a chance to spot potential
errors.
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