The following glossary was prepared to help the
consumer become familiar with the most common terms
used in clinical trials.
ADVERSE REACTION (Adverse Event) An unwanted
effect caused by the administration of drugs. Onset
may be sudden or develop over time.
ADVOCACY AND SUPPORT GROUPS
Organizations and groups that actively
support participants and their families with
valuable resources, including self-empowerment and
survival tools.
APPROVED DRUGS In
the U.S., the Food and Drug Administration (FDA)
must approve a substance as a drug before it can be
marketed.
The approval process involves several steps
including pre-clinical laboratory and animal
studies, clinical trials for safety and efficacy,
filing of a New Drug Application by the manufacturer
of the drug, FDA review of the application, and FDA
approval/rejection of application.
ARM Any of the
treatment groups in a randomized trial. Most
randomized trials have two "arms," but some have
three "arms," or even more.
BASELINE
1. Information gathered at the beginning of a study
from which variations found in the study are
measured.
2. A known value or quantity with which an unknown
is compared when measured or assessed.
3. The initial time point in a clinical trial, just
before a participant starts to receive the
experimental treatment which is being tested. At
this reference point, measurable values such as CD4
count are recorded. Safety and efficacy of a drug
are often determined by monitoring changes from the
baseline values.
BIAS When a point of
view prevents impartial judgment on issues relating
to the subject of that point of view. In clinical
studies, bias is controlled by blinding and
randomization.
BLIND A randomized
trial is "Blind" if the participant is not told
which arm of the trial he is on. A clinical trial is
"Blind" if participants are unaware on whether they
are in the experimental or control arm of the study;
also called masked.
CLINICAL Pertaining
to or founded on observation and treatment of
participants, as distinguished from theoretical or
basic science.
CLINICAL ENDPOINT
See Endpoint.
CLINICAL INVESTIGATOR
A medical researcher in charge of carrying
out a clinical trial's protocol.
CLINICAL TRIAL 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.
COHORT In epidemiology,
a group of individuals with some characteristics in
common.
COMMUNITY-BASED CLINICAL
TRIAL (CBCT) A clinical trial conducted
primarily through primary-care physicians rather
than academic research facilities.
COMPASSIONATE USE A
method of providing experimental therapeutics prior
to final FDA approval for use in humans. This
procedure is used with very sick individuals who
have no other treatment options. Often, case-by-case
approval must be obtained from the FDA for
"compassionate use" of a drug or therapy.
COMPLEMENTARY AND
ALTERNATIVE THERAPY Broad range of healing
philosophies, approaches, and therapies that Western
(conventional) medicine does not commonly use to
promote well-being or treat health conditions.
Examples include acupuncture, herbs, etc. Internet
Address:
http://www.nccam.nih.gov.
CONFIDENTIALITY REGARDING
TRIAL PARTICIPANTS Refers to maintaining the
confidentiality of trial participants including
their personal identity and all personal medical
information. The trial participants' consent to the
use of records for data verification purposes should
be obtained prior to the trial and assurance must be
given that confidentiality will be maintained.
CONTRAINDICATION A
specific circumstance when the use of certain
treatments could be harmful.
CONTROL A control is
the nature of the intervention control.
CONTROL GROUP 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.
CONTROLLED TRIALS
Control is a standard against which experimental
observations may be evaluated. In clinical trials,
one group of participants is given an experimental
drug, while another group (i.e., the control group)
is given either a standard treatment for the disease
or a placebo.
DATA SAFETY AND MONITORING
BOARD (DSMB) An independent committee,
composed of community representatives and clinical
research experts, that reviews data while a clinical
trial is in progress to ensure that participants are
not exposed to undue risk. A DSMB may recommend that
a trial be stopped if there are safety concerns or
if the trial objectives have been achieved.
DIAGNOSTIC TRIALS
Refers to trials that are are conducted to find
better tests or procedures for diagnosing a
particular disease or condition. Diagnostic trials
usually include people who have signs or symptoms of
the disease or condition being studied.
DOSE-RANGING STUDY A
clinical trial in which two or more doses of an
agent (such as a drug) are tested against each other
to determine which dose works best and is least
harmful.
DOUBLE-BLIND STUDY A
clinical trial design in which neither the
participating individuals nor the study staff knows
which participants are receiving the experimental
drug and which are receiving a placebo (or another
therapy).
Double-blind trials are thought to produce objective
results, since the expectations of the doctor and
the participant about the experimental drug do not
affect the outcome; also called double-masked study.
DOUBLE-MASKED STUDY See
Double-Blind Study.
DRUG-DRUG INTERACTION
A modification of the effect of a drug when
administered with another drug. The effect may be an
increase or a decrease in the action of either
substance, or it may be an adverse effect that is
not normally associated with either drug.
DSMB See Data Safety
and Monitoring Board.
EFFICACY (Of a drug or
treatment) The maximum ability of a drug or
treatment to produce a result regardless of dosage.
A drug passes efficacy trials if it is effective at
the dose tested and against the illness for which it
is prescribed.
In the procedure mandated by the FDA, Phase II
clinical trials gauge efficacy, and Phase III trials
confirm it (See Food and Drug Administration (FDA),
Phase II and III Trials).
ELIGIBILITY CRITERIA
Summary criteria for participant selection; includes
Inclusion and Exclusion criteria. (See
Inclusion/Exclusion Criteria)
EMPIRICAL Based on
experimental data, not on a theory.
ENDPOINT Overall
outcome that the protocol is designed to evaluate.
Common endpoints are severe toxicity, disease
progression, or death.
EPIDEMIOLOGY The
branch of medical science that deals with the study
of incidence and distribution and control of a
disease in a population.
EXCLUSION/INCLUSION
CRITERIA See Inclusion/Exclusion Criteria.
EXPANDED ACCESS
Refers to any of the FDA procedures, such as
compassionate use, parallel track, and treatment IND
that distribute experimental drugs to participants
who are failing on currently available treatments
for their condition and also are unable to
participate in ongoing clinical trials.
EXPERIMENTAL DRUG A
drug that is not FDA licensed for use in humans, or
as a treatment for a particular condition.
FDA See Food and
Drug Administration.
FOOD AND DRUG
ADMINISTRATION (FDA) The U.S. Department of
Health and Human Services agency responsible for
ensuring the safety and effectiveness of all drugs,
biologics, vaccines, and medical devices, including
those used in the diagnosis, treatment, and
prevention of HIV infection, AIDS, and AIDS-related
opportunistic infections.
The FDA also works with the blood banking industry
to safeguard the nation's blood supply. Internet
address:
http://www.fda.gov/.
HYPOTHESIS A
supposition or assumption advanced as a basis for
reasoning or argument, or as a guide to experimental
investigation.
INCLUSION/EXCLUSION
CRITERIA The medical or social standards
determining whether a person may or may not be
allowed to enter a clinical trial. These criteria
are based on such factors as age, gender, the type
and stage of a disease, previous treatment history,
and other medical conditions.
It is important to note that inclusion and
exclusion criteria are not used to reject people
personally, but rather to identify appropriate
participants and keep them safe.
IND See
Investigational New Drug.
INFORMED CONSENT 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.
INFORMED CONSENT DOCUMENT
A document that describes the rights of the
study participants, and 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.
INSTITUTIONAL REVIEW BOARD
(IRB)
1. A committee of physicians, statisticians,
researchers, community advocates, and others that
ensures that a clinical trial is ethical and that
the rights of study participants are protected. All
clinical trials in the U.S. must be approved by an
IRB before they begin.
2. Every institution that conducts or supports
biomedical or behavioral research involving human
participants must, by federal regulation, have an
IRB that initially approves and periodically reviews
the research in order to protect the rights of human
participants.
INTENT TO TREAT
Analysis of clinical trial results that includes all
data from participants in the groups to which they
were randomized ( See Randomization) even if they
never received the treatment.
INTERVENTION NAME
The generic name of the precise intervention being
studied.
INTERVENTIONS Primary
interventions being studied: types of interventions
are Drug, Gene Transfer, Vaccine, Behavior, Device,
or Procedure.
INVESTIGATIONAL NEW DRUG
A new drug, antibiotic drug, or biological
drug that is used in a clinical investigation. It
also includes a biological product used in vitro for
diagnostic purposes.
IRB See
Institutional Review Board.
MASKED The knowledge
of intervention assignment. See Blind
NATURAL HISTORY STUDY
Study of the natural development of something
(such as an organism or a disease) over a period of
time.
NEW DRUG APPLICATION (NDA)
An application submitted by the manufacturer
of a drug to the FDA - after clinical trials have
been completed - for a license to market the drug
for a specified indication.
OFF-LABEL USE A drug
prescribed for conditions other than those approved
by the FDA.
OPEN-LABEL TRIAL A
clinical trial in which doctors and participants
know which drug or vaccine is being administered.
ORPHAN DRUGS An FDA
category that refers to medications used to treat
diseases and conditions that occur rarely. There is
little financial incentive for the pharmaceutical
industry to develop medications for these diseases
or conditions. Orphan drug status, however, gives a
manufacturer specific financial incentives to
develop and provide such medications.
PEER REVIEW Review
of a clinical trial by experts chosen by the study
sponsor. These experts review the trials for
scientific merit, participant safety, and ethical
considerations.
PHARMACOKINETICS The
processes (in a living organism) of absorption,
distribution, metabolism, and excretion of a drug or
vaccine.
PHASE I TRIALS
Initial studies to determine the metabolism and
pharmacologic actions of drugs in humans, the side
effects associated with increasing doses, and to
gain early evidence of effectiveness; may include
healthy participants and/or patients.
PHASE II TRIALS
Controlled clinical studies conducted to evaluate
the effectiveness of the drug for a particular
indication or indications in patients with the
disease or condition under study and to determine
the common short-term side effects and risks.
PHASE III TRIALS
Expanded controlled and uncontrolled trials after
preliminary evidence suggesting effectiveness of the
drug has been obtained, and are intended to gather
additional information to evaluate the overall
benefit-risk relationship of the drug and provide
and adequate basis for physician labeling.
PHASE IV TRIALS
Post-marketing studies to delineate additional
information including the drug's risks, benefits,
and optimal use.
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. No sick participant receives a placebo if
there is a known beneficial treatment. (See Placebo
Controlled Study).
PLACEBO CONTROLLED STUDY
A method of investigation of drugs in which
an inactive substance (the placebo) is given to one
group of participants, while the drug being tested
is given to another group. The results obtained in
the two groups are then compared to see if the
investigational treatment is more effective in
treating the condition.
PLACEBO EFFECT A
physical or emotional change, occurring after a
substance is taken or administered, that is not the
result of any special property of the substance. The
change may be beneficial, reflecting the
expectations of the participant and, often, the
expectations of the person giving the substance.
PRECLINICAL Refers
to the testing of experimental drugs in the test
tube or in animals - the testing that occurs before
trials in humans may be carried out.
PREVENTION TRIALS
Refers to trials to find 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.
PROTOCOL 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 (See
Inclusion/Exclusion Criteria).
QUALITY OF LIFE TRIALS (or
Supportive Care trials) Refers to trials that
explore ways to improve comfort and quality of life
for individuals with a chronic illness.
RANDOMIZATION A
method based on chance by which study participants
are assigned to a treatment group. Randomization
minimizes the differences among groups by equally
distributing people with particular characteristics
among all the trial arms.
The researchers do not know which treatment is
better. From what is known at the time, any one of
the treatments chosen could be of benefit to the
participant (See Arm).
RANDOMIZED TRIAL A
study in which participants are randomly (i.e., by
chance) assigned to one of two or more treatment
arms of a clinical trial. Occasionally placebos are
utilized. (See Arm and Placebo).
RISK-BENEFIT RATIO
The risk to individual participants versus the
potential benefits. The risk/benefit ratio may
differ depending on the condition being treated.
SCREENING TRIALS
Refers to trials which test the best way to detect
certain diseases or health conditions.
SIDE EFFECTS Any
undesired actions or effects of a drug or treatment.
Negative or adverse effects may include headache,
nausea, hair loss, skin irritation, or other
physical problems. Experimental drugs must be
evaluated for both immediate and long-term side
effects (See Adverse Reaction).
SINGLE-BLIND STUDY A
study in which one party, either the investigator or
participant, is unaware of what medication the
participant is taking; also called single-masked
study. (See Blind and Double-Blind Study).
SINGLE-MASKED STUDY
See Single-Blind Study.
STANDARD TREATMENT A
treatment currently in wide use and approved by the
FDA, considered to be effective in the treatment of
a specific disease or condition.
STANDARDS OF CARE
Treatment regimen or medical management based on
state of the art participant care.
STATISTICAL SIGNIFICANCE
The probability that an event or difference
occurred by chance alone. In clinical trials, the
level of statistical significance depends on the
number of participants studied and the observations
made, as well as the magnitude of differences
observed.
STUDY ENDPOINT A
primary or secondary outcome used to judge the
effectiveness of a treatment.
STUDY TYPE The
primary investigative techniques used in an
observational protocol; types are Purpose, Duration,
Selection, and Timing.
TOXICITY An adverse
effect produced by a drug that is detrimental to the
participant's health. The level of toxicity
associated with a drug will vary depending on the
condition which the drug is used to treat.
TREATMENT IND IND
stands for Investigational New Drug application,
which is part of the process to get approval from
the FDA for marketing a new prescription drug in the
U.S. It makes promising new drugs available to
desperately ill participants as early in the drug
development process as possible.
Treatment INDs are made available to participants
before general marketing begins, typically during
Phase III studies. To be considered for a treatment
IND a participant cannot be eligible to be in the
definitive clinical trial.
TREATMENT TRIALS
Refers to trials which test new treatments, new
combinations of drugs, or new approaches to surgery
or radiation therapy.
Source
Glossary of Clinical Trial Terms.
ClinicalTrials.gov. National Institutes of Health.
Reviewed by V. J. Smith, RN, BSN, MA, September
12, 2005.
