The Handbook of Medical Informatics provides a systematic overview of medical and health informatics for physicians, nurses, and other health care professionals. At the same time the Handbook is an ¡ntroduction for students in medicine and health care, as they will be the future clinical professionals. Health care professionals will use computers to support patient care, assess the quality of care, and enhance decisión making, management, planning, and medical research. Computer-based patient records and electronic communication with be the most visible developments in the years ahead. The Handbook has been written by a host of renowned international authorities in medical and health informatics. The editors took care that the Handbook wouid not be merely a collection of sepárate chapters, but rather wouid offer a consistent and structured overview of the field. Further material for advanced studies is provided on the Wortd Wide Web site associated with this Handbook. The Handbook contains many illustrations (all in color) and tables, as well as Panel s that provide details on aspects of methods and systems. The Handbook also contains an extensivo glossary and hyperlinks both to the glossary and to the Handbook's Web site. Illustrations, exercises, questions and answers, and references to the literature are made available to readers on the Web site.