Control/control
group: in a trial the control is usually a
group of people who receive a placebo instead of the experimental treatment and
this group is used as the standard by which to evaluate findings.
Double-blind:
in a double-blind trial neither the
participants nor the researchers know who is receiving the active treatment and
who is receiving placebo. This is in contrast to a single-blind
trial where the researchers know, but not the participants, who is in which
group, or an open-label trial in which both participants and researchers know
who is receiving the active treatment or placebo.
Eligibility
criteria: guidelines for an individual study to
determine who is suitable and able to participate. A study will require that participants share
certain criteria, for example gender, age, medical history, to ensure that
trial results are due to the treatment under investigation and are not
influenced by other factors. This allows
for more accurate and meaningful results.
Inclusion/exclusion
criteria: agreed standards used to identify who
is suitable for a particular study.
These standards also ensure the safety of those who enrol and generally
include gender, age, previous treatments received, the stage of a condition and
other co-existing medical conditions.
Informed
consent: a document that details the study in
very understandable terms. This usually
includes the purpose and duration of the study, the proposed treatment, its
potential benefits and risks, details of any studies to date, agreed procedures
and key contacts. All participants must
give their consent based on the information contained in this document. If
unable to give consent then someone authorised to act on their behalf must do
so. Although this document must be
signed, it does not constitute a contract and volunteers can withdraw from a
study at any time.
Placebo:
a placebo is a pill, liquid or other
form of treatment that has no active medication in itself. It is usually used alongside an active form
of the treatment or compound being trialled.
Use of a placebo against the active treatment allows comparisons to be
made on efficacy.
Protocol:
a very detailed plan which forms the
basis for the conduct of a scientific or medical experiment, treatment, or
procedure. A protocol is in place for
all clinical trials both to protect the participants and to answer specific
research questions. Key points in a
protocol include the nature of the participants, the schedule of any procedures
or tests, the medications and dosages involved, and the time-span of the
study.
Screening:
process for the selection of study participants based on agreed eligibility criteria (see above).
