Perfect for graduate and undergraduate students, this book helps the reader understand some of the most elusive fundamentals of epidemiology and biostatistics. The sixth edition has been thoroughly revised and further clarifies difficult concepts such as person-time incidence rates, confounding, effect modification, P values, and survival analysis. The authors have also covered new topics that are increasingly seen in current literature such as attributable risk, the use of odds and the application of probabilistic concepts in epidemiology, the reliability of screening tests, and longitudinal regression models.