Over the past fifty years, the case-control method, and to a lesser extent its case-based variants, have become the most important tools for the investigator of health problems. The case control method is the study of persons with the disease and a suitable control group of persons who do not have the disease. The book helps readers address a number of general and specific questions dealing with the case-control and other case-based methods, including questions of how to design and implement a case-control study that minimizes biases, how to analyze the data to appropriately deal with confounding variables and help identify reactions, and how to interpret data and present the results from a case-control study.