The goal of this text is to provide you with the tools and skills you need to be a smart user and consumer of medical statistics. This goal has guided the selection of material and in the presentation of information. This chapter outlines the reasons physicians, medical students, and others in the health care field should know biostatistics. It also describes how the book is organized, what you can expect to find in each chapter, and how you can use it most profitably.
THE SCOPE OF BIOSTATISTICS & EPIDEMIOLOGY
The word “statistics” has several meanings: data or numbers, the process of analyzing the data, and the description of a field of study. It derives from the Latin word status, meaning “manner of standing” or “position.” Statistics were first used by tax assessors to collect information for determining assets and assessing taxes—an unfortunate beginning and one the profession has not entirely lived down.
Everyone is familiar with the statistics used in baseball and other sports, such as a baseball player's batting average, a bowler's game point average, and a basketball player's free-throw percentage. In medicine, some of the statistics most often encountered are called means, standard deviations, proportions, and rates. Working with statistics involves using statistical methods that summarize data (to obtain, for example, means and standard deviations) and using statistical procedures to reach certain conclusions that can be applied to patient care or public health planning. The subject area of statistics is the set of all the statistical methods and procedures used by those who work with statistics. The application of statistics is broad indeed and includes business, marketing, economics, agriculture, education, psychology, sociology, anthropology, and biology, in addition to our special interest, medicine and other health care disciplines. The terms biostatistics and biometrics refer to the application of statistics in the health-related fields.
Although the focus of this text is biostatistics, some topics related to epidemiology are included as well. The term “epidemiology” refers to the study of health and illness in human populations, or, more precisely, to the patterns of health or disease and the factors that influence these patterns; it is based on the Greek words for “upon” (epi) and “people” (demos). Once knowledge of the epidemiology of a disease is available, it is used to understand the cause of the disease, determine public health policy, and plan treatment. The application of population-based information to decision-making about individual patients is often referred to as clinical epidemiology and, more recently, evidence-based medicine. The tools and methods of biostatistics are an integral part of these disciplines.
BIOSTATISTICS IN MEDICINE
Clinicians must evaluate and use new information throughout their lives. The skills you learn in this text will assist in this process because they concern modern knowledge acquisition methods. The most important reasons for learning biostatistics ...