From the Department of Epidemiology at Johns Hopkins University and continuing in the tradition of award-winning educator and epidemiologist Dr. Leon Gordis, comes the fully revised 9th Edition of Gordis Epidemiology. This bestselling text provides a solid introduction to basic epidemiologic principles as well as practical applications in public health and clinical practice, highlighted by real-world examples throughout. New coverage includes expanded information on genetic epidemiology, epidemiology and public policy, and ethical and professional issues in epidemiology, providing a strong basis for understanding the role and importance of epidemiology in today’s data-driven society.