Building on the success of the first and second editions, the updated third edition of the Handbook of Epidemiology serves as a major reference for all researchers who want to conduct epidemiological studies or who want to deepen their understanding of epidemiological concepts, methods, and areas of application. The new edition provides an update of all chapters of the second edition and includes additional new chapters to account for recent developments in the field.  The book provides a comprehensive overview of the field and covers basic approaches as well as novel and advanced methodologies with a strong applied focus by integrating the most relevant state-of-the-art knowledge that otherwise could only be gathered from single specialist publications dispersed over various scientific journals. It reviews the key issues and methodological approaches pertinent to the field for which the reader pursues an expatiated overview. It may thus serve both as a firstorientation for the interested reader and as a starting point for an in-depth study of a specific area as well as a quick reference and a recapitulatory update for the expert. The broad scope of the book becomes apparent by its five sections that facilitate an integration of epidemiological concepts and methods, statistical tools, applications, and epidemiological practice: Part I covers Concepts and Designs in Epidemiology; Part II, Methodological Approaches in Epidemiology; Part III, Statistical Methods in Epidemiology; Part IV, Exposure-Oriented Epidemiology; and Part V, Outcome-Oriented Epidemiology.  All chapters follow a similar structure and highlight cross-references to related topics and specialist knowledge to be found in the Handbook. They give an overview of the topic and the most important problems and approaches that are illustrated by examples. Each chapter serves as an introductory text that helps to enter a new field by addressing basic concepts without being too elementary. Thus, it also is of interest for readers who are familiar with the particular topic by reflecting on its state-of-the-art and future perspectives. Each chapter stands on its own and comprises introductory elements that can be understood by the novice, i.e., a readership not being too familiar with the methodological background, and extends to in-depth knowledge that may serve as a reference for the trained epidemiologist. The standard procedures and methods, basic concepts, and knowledge are presented as well as recent advances and new perspectives. The list of references thus covers the whole range from introductory texts to publications for the advanced reader. In particular, the chapters on statistical methods are written for researchers in health sciences who do not have the background of theoretical statisticians and may be in need of application-oriented tools. These chapters offer numerous examples, practical applications, and illustrations.  Handbook of Epidemiology, 3rd Edition, is a relevant resource for professionals involved in health research, health reporting, health promotion, disease prevention, health services, and health systems administration, as well as those who need a reference book that covers all aspects of epidemiology as a comprehensive consultant for specific topics. The Handbook also is a useful text for researchers and graduate students in all disciplines related to epidemiology and public health.