Understanding Clinical Trial Design - Research Advocacy Network

UNDERSTANDING CLINICAL TRIAL DESIGN: A TUTORIAL FOR RESEARCH ADVOCATES
Protocol An action plan for a clinical trial. The plan states what
the study will do, how, and why. It explains how many
people will be in it, who is eligible to participate, what
study agents or other interventions they will be given,
what tests they will receive and how often, and what
information will be gathered.
Quality of Life Measurement of aspects of an individual's sense of well-
(QOL) being and ability to perform various tasks.
Randomization The process by which patients are assigned by chance to
separate groups that compare different treatments or
other interventions. Randomization can use equal
weighting (i.e., 50:50) or not (e.g., 75:25)
Randomized A research design used for testing the effectiveness of a
Controlled drug, or any other type of experimental intervention, in
Trial which research participants are assigned randomly to
experimental and control or groups and the differences
in outcomes are compared.
Randomized Design in which all patients initially receive the experi-
Discontinuation mental treatment. In a second stage of the trial a sub-
Design group of patients is randomized. Compared to traditional
designs, these designs generally provide better
information about the sub-set of patients most likely to
benefit from an experimental treatment and are often
preferred by patients.
Reliability Reliability is the extent to which an experiment, test, or
any measuring procedure yields the same result on
repeated trials. Without the agreement of independent
observers able to replicate research procedures, or the
ability to use research tools and procedures that yield
consistent measurements, researchers would be unable to
satisfactorily draw conclusions, formulate theories, or
make claims about the generalizability of their research.
Research Advocate Individuals or organizations who try to raise public
awareness about important cancer issues, particularly
those related to research. They work with researchers to
ensure that research is patient focused and likely to result
in changes in clinical practice.
Sample A subset of a population selected to draw inferences
about the population. It is a random sample if it is
chosen in such a way that every sample of the same size
has an equal chance of being selected.
Sampling Every statistic is a random variable because its value
Distribution varies from one sample to another. The distribution of
this random variable is a sampling distribution.
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