Cross-over Trials in Clinical Research
Chapter One
Introduction
1.1 THE PURPOSE OF THIS CHAPTER
In clinical medicine, cross-over trials are experiments in which subjects,
whether patients or healthy volunteers, are each given a number of treatments
with the object of studying differences between these treatments. The
commonest of all such designs is one in which approximately half of the patients are first
given an active treatment or verum and on a subsequent occasion a dummy
treatment or placebo whereas the rest of the patients are first given placebo and
then on a subsequent occasion verum. This is a simple example of a type of
design which we shall consider in detail in Chapter 3.
The purpose of this chapter, however, is simply to provide some gentle
exposition, in very general terms, of some features of cross-over trials. In
particular we shall:
define cross-over trials;
explain why they are performed;
mention clinical spec ... read full excerpt from Cross-over Trials in Clinical Research ebook
