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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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