Introduction

Two public health professionals stand near a table under an awning that says City of Pasadena Human Services and Recreation Department. The table has papers and medical supplies on it. A community member stands in front of the table filling out a document on a clipboard.

Figure 12.1 Public health professionals often bring vaccine clinics to the community as a primary method to prevent disease and improve the health of the community. (credit: modification of work “Public Health at Work” by Thad Zajdowicz/Flickr, Public Domain)

Chapter Outline

12.1 Epidemiology Defined

12.2 Historical Perspective

12.3 Epidemiological Approaches

12.4 Types of Study Design

12.5 Epidemiologic Measures

12.6 Communicating Inferences from Epidemiologic Data

12.7 The Role of Epidemiology in Scientific Decision-Making and Policy Development

Did you ever wonder where clinical guidelines originate? For example, screening for lung cancer with computed tomography is recommended for adults 50–80 years of age who have a 20-pack-a-year smoking history. On what evidence is this recommendation based? Recommendations like this one are the result of epidemiological study. This chapter will introduce basic concepts of epidemiology, how it has evolved, and how it is used today, focusing on the application of epidemiology to public health practice.