the data was originally acquired. Observational studies of clinicians' information needs provide details on the kinds of information physicians require to make decisions regarding the care of their patients (Tang et al., 1994). Up to 81 percent of the time, physicians could not find all the available patient information desired to make patient care decisions during an outpatient encounter. Limited by a format that has not substantively changed in close to a century, the paper record is ill-suited to the information demands of modern clinical practice. Most CPR system vendors offer products that combine data from various sources and present an integrated view to clinicians.
Providers often need other information in addition to patient data and their own personal knowledge (Covell et al., 1985). The guidelines, rules, and regulations in the managed care environment have intensified this need to access medical and administrative knowledge at the time decisions are made. CPR systems sometimes provide methods for organizations to incorporate access to local knowledge resources, but generally, this knowledge access is passive. That is, the user searches for the needed information electronically but has to abstract the pertinent content and enter any relevant orders manually into the clinical system. Ideally, access to knowledge resources should be integrated with clinical decision support in ways that directly influence physicians' ordering behavior, as described below.
Physician orders initiate clinical interventions. Proactively influencing physicians' orders is the most efficient way to influence patient outcomes (McDonald, 1976, 1984). Systems that physicians use routinely to enter orders, whether in the impatient setting or outpatient setting, can produce significant effects on quality and costs of care (Barnett, 1984; Tierney et al., 1987, 1990, 1993; Sittig and Stead, 1994). In addition, when clinical data are entered and maintained by the clinicians responsible for care, the accuracy and quality of data are high. Very few commercial systems, however, are used by physicians to write all their orders. Human-computer interface issues and perceived benefit substantially affect the success of this function. Some of the reasons are discussed later under remaining barriers.
With an increasing emphasis on outpatient care, coordinating the activities of health care professionals from multiple organizations at different sites, including the home, becomes more important. No longer confined to an acute care facility