Daniel J. Essin

The HL7 Clinical Document Architecture

Many people know of Health Level 7 (HL7) as an organization that creates health care messaging standards. Health Level 7 is also developing standards for the representation of clinical documents (such as discharge summaries and progress notes). These document standards make up the HL7 Clinical Document Architecture (CDA). The HL7 CDA Framework, release 1.0, became an ANSI-approved HL7 standard in November 2000. This article presents the approach and objectives of the CDA, along with a technical overview of the standard. The CDA is a document markup standard that specifies the structure and semantics of clinical documents. A CDA document is a defined and complete information object that can include text, images, sounds, and other multimedia content. The document can be sent inside an HL7 message and can exist independently, outside a transferring message. The first release of the standard has attempted to fill an important gap by addressing common and largely narrative clinical notes. It deliberately leaves out certain advanced and complex semantics, both to foster broad implementation and to give time for these complex semantics to be fleshed out within HL7. Being a part of the emerging HL7 version 3 family of standards, the CDA derives its semantic content from the shared HL7 Reference Information Model and is implemented in Extensible Markup Language. The HL7 mission is to develop standards that enable semantic interoperability across all platforms. The HL7 version 3 family of standards, including the CDA, are moving us closer to the realization of this vision.

Patterns of trust and policy

This paper proposes a new paradigm of trust and policy that provides a unified treatment of organizational and data system policies. Policy is the programming language of organizations and just like any other language must be formally specified or specifiable. This paper attempts to demonstrate that it is specifiable. Trust is a major component of policy. Trust is presented as a function of specific elements - identity, reputation, capability, stake and benefit. These elements are defined and presented in the form of a trust equation. The points at which trust enters into the formal definition of policy are identified. The trust equation provides a useful way do &scribe trust in general that is not circular (unlike many previous definitions). The resulting constructs can be st&iently nontechnical that both systems people and those without a technical background can understand them The availability of a common language to guide analysis of policy requirements, policy formulation and policy execution may provide a way for organizations to break out of a recurring cycle of policy failures.

The electronic medical record: a challenge for computer science to develop clinically and socially relevant computer systems to coordinate information for patient care and analysis

Abstract Creating a Patient Centered Information System (PCIS) or Electronic Medical Record System (EMRS)—the former terminology emphasizing the clinical purpose, the latter the missing product—is now viewed by the health care community as necessary to coordinate modern patient care in a manner that can control costs. However, despite 25 years of significant effort, the distance between the information systems available today in health care and what will be needed to fulfill this promise in the future remains very large. Success depends on achieving three goals that are generally in conflict: (1) giving the users the full scope of features and detail needed to create and use electronic clinical records for decision making, (2) providing the speed and reliability necessary for their online use, and (3) preserving system security and patient confidentiality. The vendors of the current generation of Hospital Information Systems (HIS) are being asked to supply these new capabilities before most have fully suc...

Healthcare information architecture: elements of a new paradigm

An Electronic Medical Record (EMR) must provide a secure, permanent archive for an individuals medical records and also function as a multi-purpose database that supports the complex, varied activities of patient care. Meeting these objectives requires unusual flexibility in how data are retrieved and processed. Semantic and referential integrity must preserved both over time and as chunks of information are exchanged with other systems. Relationships between data entries must determined dynamically based on actual events, rather than statically through application design. Distributed data requires that new forms of system security be incorporated into an EMR at a structural level, with an emphasis on the labeling of elements to be secured behind a security barrier, with audit trails to document necessary overrides and monitor for suspicious use. A modular information architecture is proposed that integrates requirements for structure, content, processing and security.

Experimental identification of technical and database factors that can affect the success of clinical computer systems

SummaryThe entry of clinical data into computer systems is an extremely demanding form of transaction processing. High speed is important, especially if the collection involves real-time data. Clinicians must feel that they intuitively understand a system and that it is responsive. Medical data must be easily accommodated without sacrificing accuracy or completeness. Most systems cannot do this. Clinical systems that involve on-line storage of data from patients should employ data-base technology. Systems that lack any of the following capabilities will not succeed: manual data entry, a data dictionary, a file system, utility functions, ad hoc query, and a statistical report generator. These general capabilities must satisfy a number of specific functional requirements if the entire system is to be a success. A group of such requirements have been experimentally validated. These will be discussed and a more comprehensive list presented.

Paediatric anaesthetic management with the aid of a computer

A computer program has been developed to assist in the preparation of proper drug and anaesthetic doses for children.An individualized reference sheet containing the doses of the more commonly used drugs for the induction and maintenance of anaesthesia, fluid requirements, blood volume information, ventilatory variables, estimated endotracheal tube sizes and emergency drug doses constitutes the output of this program.The importance of such a computer program in improving paediatric anaesthetic management is discussed.