Seamlessly blending theory and practice, Aschengrau & Seage Essentials of Epidemiology in Public Health presents both traditional and modern epidemiological concepts in a clear and accessible way. Broad in scope, the text opens with five chapters covering the basic epidemiologic concepts and data sources. A major emphasis is placed on study design, with separate chapters devoted to each of the three main analytic designs: experimental, cohort, and case-control studies. Full chapters on bias, confounding, and random error, including the role of statistics in epidemiology, ensure that students are well-equipped with the necessary information to interpret the results of epidemiologic studies. For the 5th edition, descriptive data and statistics have been updated throughout, most significantly in Chapters 4 (Sources of Public Health Data) and 5 (Descriptive Epidemiology). The latter chapter also includes a section on the leading causes of morbidity in the U.S. with a summary of COVID-19.