The objective of this book is to provide a comprehensive overview of the field of epidemiology, bridging the gap between standard textbooks of epidemiology and publications for specialists with a narrow focus on specific areas. It reviews the key issues, methodological approaches and statistical concepts pertinent to the field for which the reader seeks a detailed overview. It thus serves both as a first orientation for the interested reader and a starting point for an in-depth study of a specific area, as well as a quick reference and a summarizing overview for the expert