Guide to Medical Research Studies
Clinical research is medical research that involves people. Individuals
volunteer to participate in carefully conducted investigations that
ultimately uncover better ways to treat, prevent, diagnose and
understand human disease. Clinical research includes trials that test
new treatments and therapies as well as long–term natural history
studies, which provide valuable information about how disease and
health progress. Without clinical research trials, new medications and
treatments for disease would not be possible.
Types of Clinical Research Trials

Treatment clinical trials test new ways to treat disease, such as a
new therapy, a new drug or drug combination, or new approaches to
surgery.

Prevention clinical trials seek better ways to keep people from
getting a disease—or to prevent a disease from returning.

Diagnostic and screening clinical trials seek better ways to prove
whether a person has a particular disease or condition.

Quality of life trials (or supportive care trials) explore and measure
ways to improve comfort and the quality of life for individuals with a
chronic illness.
"Phases" of Clinical Research Trials
Clinical trials are conducted in phases, with each phase a different stage of
testing. The trials at each phase have a different purpose and help scientists
answer different questions.
Pre-Clinical - Researchers test an experimental drug or treatment in
animals to evaluate its safety and determine if there will be any benefit in
humans to continue the research.
Phase I —Researchers test an experimental 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. These studies usually last days
to weeks.
Phase II —The experimental study drug or treatment is given to a larger
group of people (100–300) with the disease intended to treat to see if it is
effective and to further evaluate its safety. These studies usually last weeks
to several months.
In Phase III trials—The experimental study drug or treatment is given to
large groups of people (1,000–3,000) to confirm its effectiveness, monitor
side effects, compare it with commonly used treatments, and collect
information that will allow the experimental drug or treatment to be used
safely. These studies usually last many months to years.
In Phase IV trials—After a drug is licensed (approved by the FDA) or
treatment is launched, researchers track its safety, seeking more information
about a drug or treatment’s risks, benefits, and optimal use. These long–
term studies involving large groups of participants continue to see if any
unexpected side effects occur in a small percentage of individuals. These
studies usually last many years.
Commonly Asked Questions about Clinical Research Trials
What are "blinded" (or "masked") studies? In single- or double-blind,
also called single- or double-masked studies, participants do not know which
medicine is being used, so they can describe what happens without bias.
These studies are designed to prevent members of the research team and
study participants from influencing the results. This allows scientifically
accurate conclusions. In single-blind ("single-masked") studies, only the
patient is not told what is being given. In a double-blind study, only the
pharmacist knows; the other members of the research team and the patient
are not informed. If medically necessary, however, it always is possible to
find out what the patient is taking.
How do I know what I am agreeing to do when I join a clinical trial?
Members of the research team will explain all aspects of the study in
advance, in a process known as "informed consent." Through informed
consent, potential participants are given information about the study’s
purpose, procedures, and potential risks and benefits—both initially and
throughout the study. If you are considering joining a study, talk with your
personal healthcare providers, family members, and friends. Do not rush the
decision. And remember: It is important to ask questions.
How is my confidentiality protected? A study participant’s identity is
confidential. Although the information from a study may be widely used in
other medical research, the identities of the individuals who participate are
not shared. Participants who have talked about their experiences in clinical
research have given permission for those experiences to be shared publicly.
Are there risks in participating? Clinical trials may involve risks or
discomfort. In considering a study’s risks, two factors are important: 1) the
chance of any harm occurring and 2) the degree of harm that could result
from participating in the study. Most clinical studies pose risks of minor
discomfort, lasting only a short time, but some participants experience
complications that require medical attention. The specific risks associated
with any research protocol are described in detail in the consent document,
which participants are asked to read and sign before taking part in a study.
In addition, a member of the research team explains aloud the major risks of
participating in the study and answers any questions participants have.
Before deciding to participate, volunteers should carefully weigh these risks.
Can I join any study I want? No. Each trial has specific guidelines about
who can and who cannot participate, to ensure that the study includes people
with the exact disease or condition being studied. These inclusion/exclusion
criteria protect the safety of participants and ensure that the study results
are dependable. Participation may sometimes be ruled out because of an
individual’s age, stage of disease, other health issues, or previous treatments
Once in, can I leave a study? Participation is voluntary. Participants may
withdraw at any time.
What is an IRB? An Institutional Review Board (IRB) is an independent
committee of physicians, statisticians, community advocates, and others,
which ensure that a clinical trial is ethical and that study participants' rights
are protected. Each clinical trial conducted in the United States must be
approved and monitored by an IRB, to ensure that the risks are as low as
possible and are worth any potential benefits. In the United States,
institutions that conduct or support biomedical research involving people
must, by federal regulation, have an IRB that initially approves, and
periodically reviews, the research.
Who sponsors clinical trials? Clinical trials are sponsored or funded by
various kinds of organizations or individuals, including physicians, medical
institutions, foundations, voluntary groups, and pharmaceutical companies,
in addition to such federal agencies as the National Institutes of Health, the
Department of Defense, and the Department of Veterans Affairs. Trials can
occur in such varied locations as hospitals, universities, doctors’ offices, or
community clinics. The informed consent document will share who is
sponsoring that particular study.
Note: This guide was prepared based on information provided by the National
Institute of Health (NIH) on Clinical Research – 2009. The guide is meant to
provide an informational overview about clinical research and not as a
recommendation for health care or medical advice. For more information
about clinical research trials please contact QUEST Research Institute,
www.questri.com, 248-644-7770.