Applied Epidemiology: Theory to Practice is the book that the public health movement has been waiting for. It will be treasured by every public health worker who needs state-of-the-art information and guidance in defining health problems and attempting to solve them. It needs to be studied by policy-makers in all levels of government, in the schools of public health, and in the state and national public health associations. There has been no recognition of the crucial need for a large-scale program of federal aid to remedy the severe shortage of trained epidemiologists in state and local health departments, and to finance the development of a truly adequate information system that will provide health departments with the data required for effective planning and monitoring of programs and services.