Epidemiology for Health Promotion and Disease Prevention Professionals.

Miller RE. Binghamton, NY 139041580, The Haworth Press, 2002, hardcover/paperback, 472 pp, illus, ISBN: 0-7890-1598-6 (hardcover), 0-78901599-4 (paperback), $69.95 (hardcover), $44.95 (paperback).

Epidemiology is the study of the health of populations and communities, including the occurrence and distribution of diseases and other health outcomes. A basic premise of this text is that epidemiology is a foundational science for health promotion and disease prevention (HPDP) professionals because epidemiologic findings provide a basis for their efforts. In this work, the author aims to enhance HPDP professionals' understanding of epidemiologic principles and methods in order to better inform their practice. The book is intended for both practicing HPDP professionals and students as a nontechnical (ie, nonquantitative) introduction to basic epidemiologic methods.

Each chapter of this book consists of a dozen or so pages of content as well as review questions, Web resources, and references. A glossary is included at the end of the book. Figures often are used to supplement the material graphically. Each chapter is also accompanied by a series of questions and answers pertaining to specific objectives of healthy People 2010, a government-initiated program that the author believes is an exemplary HPDP initiative. Each chapter includes 2 sidebars that illustrate the chapter content by summarizing and citing examples in the epidemiologic literature. The sidebars also direct readers to Healthy People 2010 program objectives that are discussed at the end of each chapter. For example, a sidebar in chapter 3, "Concepts and Principles," discusses disability as a common characteristic of the recovery phase in chronic disease progression. The sidebar then refers to the objective regarding life satisfaction of people with disabilities. Although the chapters are not organized into sections, they fall loosely into 3 categories: an introduction and history of epidemiology, epidemiologic theory and principles, and commonly used types of epidemiologic studies.

The informative chapter "Historical Perspectives" covers the evolution of human understanding of disease throughout history, culminating in the "scientific notion" of disease causation that accounts for biologic determinants of disease as well as the physical and social (to which I would add economic and political) environments. The contributions of various people (eg, Hippocrates, Galen, John Snow, Robert Koch, Louis Pasteur, and Florence Nightingale) to the understanding of health and disease are highlighted, as is the role of government in public health. References to the impact of epidemics, such as bubonic plague, on human societies throughout history are scattered in other chapters.

Readers are introduced to basic epidemiologic theory in several chapters, which cover agents (eg, biological, chemical, behavioral); person, place, and time; and disease process. Referring to the epidemiologic triad of agent, host, and environment, the author presents the concepts of disease risk, causation, and prevention. Disease agents are discussed, primarily in terms of infectious disease, but also in environmental, social, behavioral, and genetic terms. A good number of basic epidemiologic concepts are defined in these chapters.

Basic types of epidemiologic studies--including surveillance (outbreak) investigations, prevalence (cross-sectional), retrospective (case-control), prospective (cohort) studies, and (clinical) trials--are each reviewed in separate chapters. A chapter on health promotion programs is also included. Each chapter discusses study design and common sources o[ bias and outlines a methodologic sequence that an epidemiologist would typically follow. A very limited and cursory reference to quantitative methods and analysis used in each type of study is also included. The 2-by-2 contingency table is introduced as a primary method of analysis, and measures of association, such as relative risk and odds ratio, are described; however, these concepts are not developed quantitatively, leaving the reader with a limited understanding of their meaning and application. Furthermore, essential analytic concepts, such as confounding, are not covered, and the discussion of statistical inference is inadequate. This is the greatest weakness of this text. As an example, confidence intervals and their use in hypothesis testing and in the determination of the precision of effect measures are essential to an understanding of epidemiology, and they are nowhere to he found in this book.

This book has other limitations as well. Overall, relatively few primary epidemiologic studies are cited as references. The majority of citations throughout the book refer to secondary sources or to textbooks. Furthermore, the actual content relating to epidemiology in each chapter is rather brief. In each chapter, "knowledge tests" regarding Healthy People 2010 objectives take up greater or equal space. One of the stated purposes of these tests is to "present examples of epidemiology as the underlying science to health promotion and disease prevention." Yet, when I looked for references to epidemiologic studies in the literature (as examples) that influence health promotion and disease prevention activities, none were to be found in the knowledge tests. An opportunity to demonstrate the effect of the science of epidemiology on HPDP is missed. Readers would be better served if the content--particularly content covering basic analytic methods--of most chapters was expanded at the expense of the largely extraneous Healthy People 2010 knowledge tests.

Physical therapists who read this book may feel excluded as HPDP professionals. In the first chapter, the Web resources are a list of HPDP professional associations. This list, however; does not include APTA. In addition, a sidebar in chapter 1 refers to personal trainers who "collaborate" with physicians by providing exercise prescriptions to their clients, and who, according to the author, are seeking insurance reimbursement for their services.

In summary, in an effort to present epidemiology using a nontechnical approach, the author has introduced serious limitations to the utility of his book. Although the reader may learn about some useful epidemiologic concepts and study designs, the perfunctory discussion of epidemiologic analysis will not help the reader to understand and interpret the scientifc evidence presented in the epidemiologic literature. For this reason, I would not recommend this book to clinicians, students, or teachers who wish to enhance their understanding of epidemiology and its contribution to evidence-based practice.

Gary Brooks, PT, DrPII, CCS 

Grand Valley State University

Grand Rapids, Mich

Dr Brooks is Associate Professor in the School of Health Professions and is Research Associate at the Grand Rapids Medical Education and Research Center.