This text focuses on areas of public health practice in which the systematic application of epidemiologic methods can have a large and positive impact. It describes how best to apply traditional epidemiologic methods for determining disease etiology to "real-life" problems in public health and health-services research. Brownson and Petitti's much-needed book bridges the gap between theoretical epidemiology and public health practice and covers a number of topics not addressed by other epidemiology texts with a focus on methods. This second edition contains a new chapter on the development and use of systematic reviews and one on epidemiology and the law. Each chapter includes one or more case studies intended to illustrate major points from the chapter and provide a basis for teaching exercises. All of the chapters are authored by leading experts in the fields of epidemiology and public health, and all are fully revised and updated.