This series is directed to health care professionals who are leading the tra- formation of health care by using information and knowledge. Launched in 1988 as Computers in Health Care, the series offers a broad range of titles: some addressed to specific professions such as nursing, medicine, and health administration; others to special areas of practice such as trauma and radi- ogy. Still other books in the series focus on interdisciplinary issues, such as the computer-based patient record, electronic health records, and networked health care systems. Renamed Health Informatics in 1998 to reflect the rapid evolution in the discipline now known as health informatics, the series will continue to add titles that contribute to the evolution of the field. In the series, eminent - perts, serving as editors or authors, offer their accounts of innovations in health informatics. Increasingly, these accounts go beyond hardware and so- ware to address the role of information in influencing the transformation of healthcare delivery systems around the world. The series also increasingly focuses on ?peopleware? and the organizational, behavioral, and societal changes that accompany the diffusion of information technology in health services environments.