Over the past several decades, epidemiology has become increasingly complex,
theoretical, and specialized. While many epidemiologists are still engaged in the
investigation of infectious disease problems, others are addressing newer challenges
such as homicides, unwanted pregnancies, environmental exposures, and
natural disasters. Computers now make it practical to analyze data in seconds that
it might otherwise take weeks or months to calculate. Whole new books have
appeared covering such areas as pharmacoepidemiology, perinatal epidemiology,
and occupational epidemiology.
Because of the increasing specialization in the real world of contemporary
health problems, there is a need for a clearly written, practical, highly usable book
devoted to fi eld epidemiology—the timely use of epidemiology to solve public
health problems. This process involves the application of basic epidemiologic
principles in real time, place and person to solve problems of an urgent or
emergency nature.
This book, intended to meet this ever expanding need, is based both on
science and experience. It deals with real problems, real places, and real people:
nature’s experiment, if you will, rather than carefully designed studies in a laboratory
or clinical setting. So, in the lexicon of the epidemiologist, the book will be
addressing issues relating to observational epidemiology—not experimental
epidemiology.