Statistical Methods in Medical Research 4ed

Preface to the fourth edition
In the prefaces to the first three editions of this book, we set out our aims
as follows: to gather together the majority of statistical techniques that are
used at all frequently in medical research, and to describe them in terms accessible
to the non-mathematician. We expressed a hope that the book would
have two special assets, distinguishing it from other books on applied statistics:
the use of examples selected almost entirely from medical research projects,
and a choice of statistical topics reflecting the extent of their usage in medical
research.
These aims are equally relevant for this new edition. The steady sales of
the earlier editions suggest that there was a gap in the literature which this
book has to some extent filled. Why then, the reader may ask, is a new edition
needed? The answer is that medical statistics (or, synonymously, biostatistics) is
an expanding subject, with a continually developing body of techniques, and
a steadily growing number of practitioners, especially in medical research
organizations and the pharmaceutical industry, playing an increasingly influential
role in medical research. New methods, new applications and changing
attitudes call for a fresh approach to the exposition of our subject.
The first three editions followed much the same infrastructure, with little
change to the original sequence of chaptersÐessentially an evolutionary
approach to the introduction of new topics. In planning this fourth edition
we decided at an early stage that the structure previously adopted had
already been stretched to its limits. Many topics previously added wherever
they would most conveniently fit could be handled better by a more radical
rearrangement. The changing face of the subject demanded new chapters
for topics now being treated at much greater length, and several areas of
methodology still under active development needed to be described much more
fully.
The principal changes from the third edition can be summarized as follows.
. Material on descriptive statistics is brought together in Chapter 2, following a
very brief introductory Chapter 1.
. The basic results on sampling variation and inference for means, proportions
and other simple measures are presented, in Chapters 4 and 5, in a more
homogeneous way. For example, the important results for a mean are treated
together in §4.2, rather than being split, as before, across two chapters.
ix