by discussions of health care costs and debate on effective ways to control them.

Although efforts at full-scale health care reform led by the federal government gained momentum, peaked, and then disintegrated, market-driven changes in health care delivery were already under way and steadily moving forward. Managed care plans continue to gain increasing shares of the market (Hoechst Marion Rousell, Inc., 1995). The need to examine and manage the health needs of a population has dramatically increased the demand for information systems that capture clinical data. The health care information systems industry has shifted its attention from financial systems to clinical systems, particularly CPR systems. Two core tenets of managed care that impact the demand for CPR systems have been the central role of primary care and the emergence of integrated delivery systems.

Managed care has redefined the primary care provider as the principal provider of care and, in many instances, a gatekeeper for access to certain diagnostic tests and specialty care. To efficiently carry out these roles, the clinician needs ready access to both clinical and administrative data. At the same time, guidelines are being promoted to reduce the variances among clinical practices. When guidelines are integrated into a CPR system, they can streamline the steps necessary to adhere to them and simultaneously document that compliance. CPR systems that integrate clinical guidelines in the order-entry process have the best acceptance among providers (Sittig and Stead, 1994; Sullivan and Mitchell, 1995; CPRI, 1996c, 1997). However, despite the abundance of guidelines, few can be implemented in a computer as written (Tierney et al., 1995). Software tools are needed to help author guidelines that are internally consistent, include precise definitions of eligibility criteria, and accommodate a variety of patient conditions.

One of the major goals of managed care is to provide more of the care outside of the hospital. However, the impatient and the outpatient settings differ substantially. There are differences in the temporal nature of information, the responsibilities of each member of the health care team, the need for a communications infrastructure to facilitate coordination of care, and other logistical concerns which impact the detailed design of information systems. Consequently, vendors of information system products for hospitals find that there is a steep learning curve to understanding the information needs of physicians in the ambulatory care setting. Deliberate analysis of the information needs and work flow requirements in ambulatory care will help system developers design information systems that increase the efficiency and effectiveness of clinical practice throughout the continuum.