A clinical trial is a research study to answer specific questions about vaccines or 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. Ideas for clinical trials usually come
from researchers. Once researchers test new therapies or procedures in the laboratory and get promising
results, they begin planning . New therapies are tested on people only after laboratory and animal studies
show promising results.
What is a protocol?
All clinical trials are based on a set of rules called a protocol. 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 are seen regularly by the research staff to monitor their health
and to determine the safety and effectiveness of their treatment.
What are clinical trial phases?
Clinical trials of experimental drugs
proceed through four phases:
In Phase I
clinical 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
clinical 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
studies, 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.
studies are done after the drug or treatment has been marketed. These studies continue testing the study
drug or treatment to collect information about their effect in various populations and any side effects
associated with long-term use.
What protections are there for people who participate
in clinical trials?
The government has strict guidelines and safeguards to protect people who choose to participate in clinical
trials. Every clinical trial in the U.S. must be approved and monitored by an Institutional Review Board
(IRB) to make sure the risks are as low as possible and are worth any potential benefits. An IRB is an
independent committee of physicians, statisticians, community advocates, and others that ensures that a
clinical trial is ethical and the rights of study participants are protected. All institutions that conduct or support
biomedical research involving people must, by federal regulation, have an IRB that initially approves and
periodically reviews the research.
What is informed consent?
is the process of learning the key facts about a clinical trial before you decide whether or not to participate.
These facts include:
Why the research is being done.
What the researchers want to accomplish.
What will be done during the trial and for how long.
What risks are involved in the trial.
What benefits can be expected from the trial.
What other treatments are available.
The fact that you have the right to leave the trial at any time.
Phase I clinical trials
If you are considering joining a clinical trial, the research staff will give you informed consent documents
that include the details about the study. If English is not your native language, you can ask for the consent
documents in languages other than English. Since joining a clinical trial is an important decision, you
should ask the research team any questions you may have about the study and the consent forms before
you make a decision.
It is also a good idea to take the consent documents home and discuss them with family members or
friends. Talking about your options can help you to feel comfortable with your decision. If you decide to
join the clinical trial, be sure to ask for a copy of the informed consent documents so you can review
them at any time.
Remember informed consent is more than signing a form. It is a process that continues through the study.
You should feel free to ask the research team questions before, during, and after the study. Informed
consent continues as long as you are in the study.
Who can participate in a clinical trial?
All clinical trials have guidelines about who can get into the program. Guidelines are based on such factors as
age, type of disease, medical history, and current medical condition. Before you join a clinical trial, you must
qualify for the study. Some research studies seek volunteers with illnesses or conditions to be studied in the
clinical trial, while others need healthy volunteers. Healthy volunteers participate in Phase I trials, vaccine
studies, and trials on research on preventive care for children or adults. The factors that allow you to
participate in a clinical trial are calledinclusion criteria and the factors that keep you from participating are
called exclusion criteria. It is important to note that inclusion and exclusion criteria are not used to reject
people personally. Instead, the criteria are used to identify appropriate participants and keep them safe.
The criteria help ensure that researchers will be able to answer the questions they plan to study.
Who sponsors clinical trials?
Clinical trials are sponsored by government agencies: such as the National Institutes of Health (NIH);
pharmaceutical companies; individual physician- investigators; health care institutions such as health
maintenance organizations (HMOs); and organizations that develop medical devices or equipment. Trials
can take place in a variety of locations, such as hospitals, universities, doctors' offices, or community
What happens during a clinical trial?
The clinical trial process depends on the kind of trial you participate in. The team will include doctors and
nurses as well as social workers and other health care professionals. They will check your health at the
beginning of the trial, give you specific instructions for participating in the trial, monitor you carefully during
the trial, and stay in touch with you after the study. Some clinical trials involve more tests and doctor visits
than you would normally have for your illness or condition. For all types of trials, you will work with a
research team. Your participation will be most successful if you follow the carefully and stay in contact
with the research staff. Some what happens in a trial are defined below.
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.
What is a control or control group?
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
protocol terms that will help you understand a standard treatment for the illness or a placebo.
What is a blinded or masked study?
A blinded or masked study is one in which participants do not know whether they are in the experimental
or control group in a research study. Those in the experimental group get the medications or treatments
being tested, while those in the control group get a standard treatment or no treatment.
What is a double-blind or double-masked study?
A double-blind or double-masked study is one in which neither the participants nor the study staff know
which participants are receiving the experimental treatment and which ones are getting either a standard
treatment or a placebo. These studies are performed so neither the patients' nor the doctors' expectations
about the experimental drug can influence the outcome.
What are side effects and adverse reactions?
Side effects are any undesired actions or effects of drug or treatment. Negative or adverse effects may
include headache, nausea, hair loss, skin irritation, or other physical problems. Experimental treatments
must be evaluated for both immediate and long-term side effects.
What are the benefits and risks associated with clinical trials?
There are both benefits and risks associated with clinical trials.
By participating in a clinical trial, you can:
Take an active role in your own health care.
Gain access to new treatments that are not available to the public.
Obtain expert medical care at leading health care facilities during the trial.
Help others by contributing to medical research.
Clinical trials have risks:
There may be side effects or adverse reactions to medications or treatments.
The treatment may not be effective for you.
They may require a lot of your time for trips to the study site, treatments, hospital stays, or complex dosage
What should I know before I join a clinical trial?
You should know as much as possible about the research study. It is important for you to feel very
comfortable asking questions and the staff should answer them in a way you can understand. A list of
How should I prepare for the meeting with
the research coordinator or doctor?
Plan ahead and write down the questions you want to ask. Ask a friend or relative to come with you for
support and to hear the responses to your questions. Bring a tape recorder so you can replay the
discussion after you get home.
What questions should I ask?
Some questions you might ask about the research include:
Why is this research being done?
What is the purpose of the study?
Who is sponsoring the study?
Who has reviewed and approved this study?
Why does the research team think the treatment, drug, or medical device will work?
Some questions about your participation in the study include:
Where is the study site?
protocol sample questions:
What kinds of therapies, procedures, and/or tests will I have during the trial?
Will they hurt? If so, for how long?
How will the tests in the study compare to tests I would have outside the study?
How long will the study last?
How often will I have to go to the study site?
Who will provide my medical care after the study ends?
Will I be able to take my regular medications during the trial?
What medications, procedures, or treatments must I avoid while in the study?
What are my responsibilities during the study?
Will I have to be in the hospital during the study?
Will the study researchers work with my doctor while I am in the study?
Can anyone find out that I am participating in a study?
Can I talk to other people in the study?
Will I be able to find out the results of the trial?
Questions about risks and benefits include:
How do the possible risks and benefits of the study compare with approved treatments for me?
What are the possible immediate and long-term side effects?
Other questions include:
What other treatment options do I have?
Will I have to pay anything to participate in the study?
What are the charges likely to be?
Is my insurance likely to cover those expenses?
Should I continue working with my primary health care provider
if I participate in a trial?
Yes. Most clinical trials provide short-term treatments related to a designated illness or condition, but not
extended or complete primary health care. In addition, by having your health care provider work with the
research team, you can ensure that your other medications or treatments will not conflict with the.
Can I leave a clinical trial after it has begun?
Yes. You can leave a clinical trial at any time. If you plan to stop participating, let the research team know
why you are leaving the study.
Will I be paid for participating in a clinical trial?
Some clinical trials will pay you for joining the trial, while others will not. In some programs, researchers
will reimburse you for expenses associated with participating in the research. Such expenses may include
transportation costs, child care, meals, and accommodations.