Historical evolution of preventive medical informatics in the USA.

A major reorganization of healthcare services is occurring in the United States. It has evolved from the solo- and group-practice models of the 1940s with fee-for-service and insurer-indemnification financing that used paper-based information systems to support preventive medical services. In the 1990s there emerged nation-wide, managed-care plans employing enhanced computer-based information systems with online preventive medical practice guidelines and Internet-supported home-care telemedicine. It is helpful to review how this major reengineering of medicine has come about.