Diagnosis Related Groups (DRGs) were the first health management tool to group patients in clinical meaningful categories with homogeneous resources consumption. DRGs have been selected in 1983 as the prospective payment system for MEDICARE patients in the USA. This innovation migrated to several Western countries first, in Eastern Europe and in Asia soon thereafter. What is the present situation? This book describes the actual state of case mix uses in twenty countries all over the world. Experts from Australia, Austria, Belgium, Denmark, Finland, France, Germany, Great Britain, Ireland, Japan, South Korea, Mexico, the Netherlands, Romania, Russia, South Africa, Spain, Sweden, Switzerland, the USA accepted to describe the development and adaptations of case mix in their country. In addition, they provide a concise analysis of health care organization, financing methods, and information checking in these countries. Such information cannot be found easily in the literature. It gives physicians, hospital managers, researchers and policy makers a basis for making decisions on new paths to develop in health care delivery systems.