For those considering participation in a clinical trial, the
following frequently asked questions are important in understanding
the role of the participant and the unique process of a clinical trial.
Participation in a Clinical Trial FAQ's
Q: Who can participate in a clinical trial?
All clinical trials have guidelines about who can participate.
Using inclusion/exclusion criteria is an important principle of
medical research that helps to produce reliable results. The
factors that allow someone to participate in a clinical trial
are called "inclusion criteria" and those that disallow someone
from participating are called "exclusion criteria". These
criteria are based on such factors as age, gender, the type and
stage of a disease, previous treatment history, and other
medical conditions. Before joining a clinical trial, a
participant must qualify for the study. Some research studies
seek participants with illnesses or conditions to be studied in
the clinical trial, while others need healthy participants. 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.
Q: What happens during a clinical trial?
The clinical trial process depends on the kind of trial being
conducted (See What are the different types of clinical trials?)
The clinical trial team includes doctors and nurses as well as
social workers and other health care professionals. They check
the health of the participant at the beginning of the trial,
give specific instructions for participating in the trial,
monitor the participant carefully during the trial, and stay in
touch after the trial is completed.
Some clinical trials involve more tests and doctor visits than
the participant would normally have for an illness or condition.
For all types of trials, the participant works with a research
team. Clinical trial participation is most successful when the
protocol is carefully followed and there is frequent contact
with the research staff.
Q: What is informed consent?
Informed consent is the process of learning the key facts about
a clinical trial before deciding whether or not to participate.
It is also a continuing process throughout the study to provide
information for participants. To help someone decide whether or
not to participate, the doctors and nurses involved in the trial
explain the details of the study. If the participant's native
language is not English, translation assistance can be provided.
Then the research team provides an informed consent document that
includes details about the study, such as its purpose, duration,
required procedures, and key contacts. Risks and potential benefits
are explained in the informed consent document. The participant
then decides whether or not to sign the document. Informed
consent is not a contract, and the participant may withdraw
from the trial at any time.
Q: What kind of preparation
should a potential participant make for the meeting with the
research coordinator or doctor?
- Plan ahead and write down possible questions to ask.
- Ask a friend or relative to come along for support
and to hear the responses to the questions.
- Bring a tape recorder to record the
discussion to replay later.
Q: What should people consider before participating in a trial?
People should know as much as possible about the clinical trial
and feel comfortable asking the members of the health care team
questions about it, the care expected while in a trial, and the
cost of the trial. The following questions might be helpful for
the participant to discuss with the health care team. Some of
the answers to these questions are found in the informed consent
document. What is the purpose of the study?
- Who is going to be in the study?
- Why do researchers believe the new
treatment being tested may be effective? Has it been
- What kinds of tests and treatments are
- How do the possible risks, side effects,
and benefits in the study compare with my current treatment?
- How might this trial affect my daily life?
- How long will the trial last?
- Will hospitalization be required?
- Who will pay for the treatment?
- Will I be reimbursed for other expenses?
- What type of long-term follow up care is
part of this study?
- How will I know that the treatment is working?
Will results of the trials be provided to me?
- Who will be in charge of my care?
Q: Does a participant
continue to work with a primary health care provider while in
Yes. Most clinical trials provide short-term treatments related
to a designated illness or condition, but do not provide
extended or complete primary health care. In addition, by having
the health care provider work with the research team, the
participant can ensure that other medications or treatments will
not conflict with the protocol.
Q: 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.
Q: What are the benefits and risks of participating in a clinical trial?
Clinical trials that are well-designed and well-executed
are the best treatment approach for eligible participants
- Play an active role in their own health
care. Gain access to new research treatments before they
are widely available.
- Obtain expert medical care at leading health
care facilities during the trial.
- Help others by contributing to medical
There are risks to participating in a clinical trial.
- There may be unpleasant, serious or even
life-threatening side effects to treatment.
- The treatment may not be effective for
- The protocol may require more of their
time and attention than would a non-protocol treatment,
including trips to the study site, more treatments, hospital
stays or complex dosage requirements.
How is the safety of the participant protected?
The ethical and legal codes that govern medical practice also apply to
clinical trials. In addition, most clinical research is federally
regulated with built in safeguards to protect the participants. The
trial follows a carefully controlled protocol, a study plan which
details what researchers will do in the study. As a clinical trial
progresses, researchers report the results of the trial at scientific
meetings, to medical journals, and to various government agencies.
Individual participants' names will remain secret and will not be
mentioned in these reports.
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
Can a participant leave a clinical trial after it has begun?
Yes. A participant can leave a clinical trial, at any time.
When withdrawing from the trial, the participant should let
the research team know about it, and the reasons for leaving
Used with permission of the National Library of Medicine.