An
Introduction to Clinical Trials
This
information is taken from the ClinicalTrials.gov
web site, A service of the National Institutes of Health, devedloped
by the National Library of Medicine.
Choosing
to participate in a clinical trial is an important personal decision.
The following frequently asked questions provide detailed information
about clinical trials. In addition, it is often helpful to talk
to a physician, family members, or friends about deciding to join
a trial. After identifying some trial options, the next step is
to contact the study research staff and ask questions about specific
trials.
|
|
A
clinical trial is a research study to answer specific questions
about vaccines, new therapies or new ways of using known treatments.
Clinical trials (also called medical research and research studies)
are used to determine whether new drugs or treatments are both safe
and effective. Carefully conducted clinical trials are the fastest
and safest way to find treatments that work in people.
|
What
is a clinical trial?
«
|
|
Why
participate in a clinical trial?
»
|
Participants
in clinical trials can play a more active role in their own health
care, gain access to new research treatments before they are widely
available, and help others by contributing to medical research
|
|
Ideas
for clinical trials usually come from researchers. After researchers
test new therapies or procedures in the laboratory and in animal
studies, the treatments with the most promising laboratory results
are moved into clinical trials. During a trial, more and more information
is gained about a new treatment, its risks and how well it may or
may not work.
|
Where
do the ideas for trials come from?
«
|
|
Who
sponsors clinical trials?
»
|
Clinical
trials are sponsored or funded by a variety of organizations or
individuals such as physicians, medical institutions, foundations,
voluntary groups, and pharmaceutical companies, in addition to federal
agencies such as the National Institutes of Health (NIH), the Department
of Defense (DOD), and the Department of Veteran's Affairs (VA).
Trials can take place in a variety of locations, such as hospitals,
universities, doctors' offices, or community clinics.
|
| A
protocol is a study plan on which all clinical trials are based. The
plan is carefully designed to safeguard the health of the participants
as well as answer specific research questions. A protocol describes
what types of people may participate in the trial; the schedule of
tests, procedures, medications, and dosages; and the length of the
study. While in a clinical trial, participants following a protocol
are seen regularly by the research staff to monitor their health and
to determine the safety and effectiveness of their treatment. |
What
is a protocol?
«
|
|
What
is a placebo?
»
|
A placebo
is an inactive pill, liquid, or powder that has no treatment value.
In clinical trials, experimental treatments are often compared
with placebos to assess the treatment's effectiveness. In some
studies, the participants in the control group will receive a
placebo instead of an active drug or treatment.
|
|
A
control is the standard by which experimental observations are evaluated.
In many clinical trials, one group of patients will be given an
experimental drug or treatment, while the control group is given
either a standard treatment for the illness or a placebo.
|
What
is a control or control group?
«
|
|
What
are the different types of clinical trials?
»

|
Treatment
trials
test new treatments, new combinations of drugs, or new approaches
to surgery or radiation therapy.
Prevention
trials look for better ways to prevent disease in people who
have never had the disease or to prevent a disease from returning.
These approaches may include medicines, vitamins, vaccines, minerals,
or lifestyle changes.
Screening
trials test the best way to detect certain diseases or health
conditions.
Quality
of Life trials (or Supportive Care trials) explore ways to improve
comfort and the quality of life for individuals with a chronic illness.
|
|
Clinical
trials are conducted in phases. The trials at each phase have a
different purpose and help scientists answer different questions:
In
Phase I trials, researchers test a new drug or treatment
in a small group of people (20-80) for the first time to evaluate
its safety, determine a safe dosage range, and identify side effects.
In
Phase II trials, the study drug or treatment is given to
a larger group of people (100-300) to see if it is effective and
to further evaluate its safety.
In
Phase III trials, the study drug or treatment is given to
large groups of people (1,000-3,000) to confirm its effectiveness,
monitor side effects, compare it to commonly used treatments, and
collect information that will allow the drug or treatment to be
used safely.
In
Phase IV trials, post marketing studies delineate additional
information including the drug's risks, benefits, and optimal use.
|
What
are the phases of clinical trials?
«
|
 |
|
home
| overview | organization
| resources | for
investigators | apply | site
map | contact us
|