Basic Statistics

CHAPTER 1

INITIAL STEPS

Statistical methods have been developed to help in understanding data and to assist in

making decisions when uncertainty exists. Biostatistics is the use of statistics applied

to biological problems and to medicine. In this book, the examples are given using

biomedical and public health data. Bio is taken from the Greek word bios, meaning

“life” so that biology actually includes numerous fields, such as ecology, fisheries,

and agriculture, but examples from those fields are not included in this book.

In Section 1.1 we discuss the two major reasons for using statistics, in Section 1.

we present the initial steps in the design of biomedical studies, and in Section 1.3 we

define the common types of biomedical studies and describe how medical studies are

rated by level of evidence and how the CONSORT guidelines for randomized clinical

trials are referenced.

1.1 REASONS FOR STUDYING BlOSTATlSTlCS

Statistics has traditionally been used with two purposes in mind. The first is to

summarize data so that it is readily comprehensible; this is called descriptive statis-

tics. Both in the past and recently, considerable effort has gone into devising meth-

ods of describing data that are easy to interpret. The use of computers and their

Basic Statistics: A Primer for the Biomedical Sciences, Fourth Edition.

By Olive Jean Dunn and Virginia A. Clark

Copyright @ 2009 John Wiley & Sons, Inc.

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