A simple, practical, step-by-step guide to the use of epidemiology as a tool for improving the management of health services. Addressed to general health workers, the book uses clear definitions, analogies, examples, checklists, sample forms and calculations, and abundant illustrations to demystify the methods of epidemiology and show how they can work in concrete situations. Particular emphasis is placed on the simple knowledge and skills needed to collect and then use epidemiological data to monitor health problems commonly found in developing countries. The book has 14 chapters. Readers are first introduced to the main tasks involved in the management of district health services and the types of information that can contribute to more effective management.