Integrated Advanced Medical Information Systems (IAIMS): Payoffs and Problems

IAIMS (Integrated Advanced Information Management Systems) is an initiative to improve the access to information needed to provide patient care, health-oriented education, biomedical research, and management of large medical center environments. This paper will review the goals, history, and accomplishments of the IAIMS initiative. Shortcomings and frustrations, lessons learned, and the future of such initiatives will also be discussed.

Building a comprehensive clinical information system from components. The approach at Intermountain Health Care

OBJECTIVES

To discuss the advantages and disadvantages of an interfaced approach to clinical information systems architecture.

METHODS

After many years of internally building almost all components of a hospital clinical information system (HELP) at Intermountain Health Care, we changed our architectural approach as we chose to encompass ambulatory as well as acute care. We now seek to interface applications from a variety of sources (including some that we build ourselves) to a clinical data repository that contains a longitudinal electronic patient record.

RESULTS

We have a total of 820 instances of interfaces to 51 different applications. We process nearly 2 million transactions per day via our interface engine and feel that the reliability of the approach is acceptable. Interface costs constitute about four percent of our total information systems budget. The clinical database currently contains records for 1.45 m patients and the response time for a query is 0.19 sec.

DISCUSSION

Based upon our experience with both integrated (monolithic) and interfaced approaches, we conclude that for those with the expertise and resources to do so, the interfaced approach offers an attractive alternative to systems provided by a single vendor. We expect the advantages of this approach to increase as the costs of interfaces are reduced in the future as standards for vocabulary and messaging become increasingly mature and functional.

Design and implementation of a multi-institution immunization registry

One of every four children in the USA is underimmunized. Surveys of children in New York City have documented rates of appropriate immunization as low as 37% in certain populations in northern Manhattan. In response to this, government and private agencies have undertaken efforts to improve immunization rates. As part of one such multiinstitution effort in northern Manhattan, we have begun implementation of a computer-based immunization registry. Key features of this registry system include adaptation of legacy software in order to perform initial capture of data in electronic format; design of a user interface using a World Wide Web server that provides data review and capture functions with appropriate security; implementation of a registry database with links to the server, communication links between hospital registration systems, a Master Patient Index, community providers and the central registry; and integration of decision support in the form of Medical Logic Modules encoded in the Arden Syntax. We discuss our design of this multi-institution immunization registry and implementation efforts to date.

Costs and benefits of connecting community physicians to a hospital WAN

The Washington Heights-Inwood Community Health Management Information System (WHICHIS) at the Columbia-Presbyterian Medical Center (CPMC) provides 15 community physician practices with seamless networking to the CPMC Wide-Area Network. The costs and benefits of the project were evaluated. Installation costs, including hardware, office management software, cabling, network routers, ISDN connection and personnel time, averaged $22,902 per office. Maintenance and support costs averaged $6,293 per office per year. These costs represent a "best-case" scenario after a several year learning curve. Participating physicians were interviewed to assess the impact of the project. Access to the CPMC Clinical Information System (CIS) was used by 87%. Other resource usage was: non-CPMC Web-based resources, 80%; computer billing, 73%; Medline and drug information databases, 67%; and, electronic mail, 60%. The most valued feature of the system was access to the CPMC CIS. The second most important was the automatic connection provided by routed ISDN. Frequency of access to the CIS averaged 6.67 days/month. Physicians reported that the system had significantly improved their practice of medicine. We are currently exploring less expensive options to provide this functionality.

Architecture for a Web-based clinical information system that keeps the design open and the access closed

We are developing the Patient Clinical Information System (PatCIS) project at Columbia-Presbyterian Medical Center to provide patients with access to health information, including their own medical records (permitting them to contribute selected aspects to the record), educational materials and automated decision support. The architecture of the system allows for multiple, independent components which make use of central services for managing security and usage logging functions. The design accommodates a variety of data entry, data display and decision support tools and provides facilities for tracking system usage and questionnaires. The user interface minimizes hypertext-related disorientation and cognitive overload; our success in this regard is the subject of on-going evaluation.

Evolution of a knowledge base for a clinical decision support system encoded in the Arden Syntax

Clinical decision support systems (CDSS) are being used increasingly in medical practice. Thus, long-term maintenance of the knowledge bases (KB) of such systems becomes important. To quantify changes that occur as a KB evolves, we studied the KB at the Columbia-Presbyterian Medical Center. This KB has a total of 229 Medical Logic Modules (MLMs) encoded in the Arden Syntax. Eliminating those never used in practice, we retrospectively analyzed 156 MLMs developed over 78 months. We noted 2020 distinct versions of these MLMs that included 5528 changed statements over time. These changes occurred primarily in the logic slot (38.7% of all changes), the action slot (17.8%), in queries (15.0%) and in the data slot exclusive of queries (12.4%). We conclude that long-term maintenance of a KB for a CDSS requires significant changes over time. We discuss the implications of these results for the design of KB editors for the Arden Syntax.

Practical lessons in remote connectivity

Community Health Information Networks (CHINs) require the ability to provide computer network connections to many remote sites. During the implementation of the Washington Heights and Inwood Community Health Management Information System (WHICHIS) at the Columbia-Presbyterian Medical Center (CPMC), a number of remote connectivity issues have been encountered. Both technical and non-technical issues were significant during the installation. We developed a work-flow model for this process which may be helpful to any health care institution attempting to provide seamless remote connectivity. This model is presented and implementation lessons are discussed.

Electronic forms: benefits drawbacks of a World Wide Web-based approach to data entry

It has long been realized that, compared to paper-based records, electronic record systems provide many advantages in the healthcare environment, including increased availability, improved legibility, long-term accessibility, (potentially) greater completeness, data encoding, and automated decision support and analysis. In spite of these recognized benefits, collection of patient data at the point of service generally does not occur, in large part because each such effort usually requires application-specific software and hardware, and, most significantly, provider time. Given the presence of WWW browsers now available on nearly every desktop, the support and access concerns for data entry applications can be substantially lessened. Despite these advantages, there are also downsides to the use of the WWW for data entry, including user interface issues and security. At CPMC, we are currently using web-based forms to gather patient charge data from physical and occupational therapists. Benefits of this approach have included a 98.2% user compliance rate for at least weekly data entry, and the reduction of charge posting from an average of 24.3 days to 2.3 days following the date of service. Drawbacks to WWW-based applications have included increased security exposure and persistent human tendencies to enter data in batches rather than at the time of service. A final conclusion was that, in the absence of a strong central mandate, providers must perceive a clear benefit in order to be willing to learn and use a new technology.

Design of a clinical event monitor

The issues and implementation of a clinical event monitor are described. An event monitor generates messages for providers, patients, and organizations based on clinical events and patient data. For example, an order for a medication might trigger the generation of a warning about a drug interaction. A model based on the active database literature has as its main components an event (which triggers a rule to fire), a condition (which tests whether an action ought to be performed), and an action (often the generation of a message). The details of implementing such a monitor are described, using as an example the Columbia-Presbyterian Medical Center clinical event monitor, which is based on the Arden Syntax for Medical Logic Modules.

Dialogue. Privacy protection: paper or computer records? Confidentiality of healthcare records

In summary, security concerns surrounding health data are justified, but solutions are surmountable with currently available technologies. Whether systems are paper or electronic, human factors such as errors, negligence and unethical activities can result in breaches of confidentiality, despite optimal implementations. Neither automated teller machines (ATMs) nor EMRs are free from instances of abuse, but policies and protocols for electronic systems can be implemented that may provide better security than analogous paper record systems.

The economic motivations for clinical information systems

For three decades (1960-1990) the primary use of computers in hospitals' in the U.S. was to ease the task of reimbursement for care rendered and to automate results reporting for high-volume, time-critical tests such as clinical laboratory procedures. Hospitals were regarded as independent organizations/revenue centers which could pass costs to third party payers. Beginning in the mid-eighties, U.S. hospitals were no longer reimbursed on a fee-for-service basis for many patients, but received a fixed payment regardless of the actual cost of treating a patient. The size of the payment depended upon the patients' type of illness (Diagnostically related group). This approach gave hospitals incentives to reduce costs, but did not foster a fully competitive environment. Now, in the mid-nineties, hospitals in the U.S. are seen as cost centers in an integrated health care delivery system. Within this environment, a longitudinal patient record is necessary to increase levels of communication between healthcare providers. While certain management functions remain hospital-centered, clinical information systems must now cover a spectrum of patient activities within the ambulatory and inpatient arena. Several of the leading healthcare providers use computer-based logic to alert care givers whenever standards of care are not being achieved. These institutions feel that such capability will be the real impetus to reduce cost and improve the quality of care. Based upon observations over four decades, it appears that economic considerations play the major role in determining which kinds of information systems are deployed in the healthcare arena.

OzCare: a workflow automation system for care plans

An automated environment for implementing and monitoring care plans and practice guidelines is very important to the reduction of hospital costs and optimization of medical care. The goal of our research effort is to design a general system architecture that facilitates the implementation of (potentially) numerous care plans. Our approach is unique in that we apply the principles and technologies of Oz a multi-user collaborative workflow system that has been used as a software engineering environment framework, to hospital care planning. We utilize not only the workflow modeling and execution facilities of Oz, but also its open-system architecture to interface it with the World Wide Web, the Medical Logic Module server, and other components of the clinical information system. Our initial proof-of-concept system, OzCare, is constructed on top of the existing Oz system. Through several experiments in which we used this system to implement some Columbia-Presbyterian Medical Center care plans, we demonstrated that our system is capable and flexible for care plan automation.

Privacy, confidentiality, and electronic medical records

The enhanced availability of health information in an electronic format is strategic for industry-wide efforts to improve the quality and reduce the cost of health care, yet it brings a concomitant concern of greater risk for loss of privacy among health care participants. The authors review the conflicting goals of accessibility and security for electronic medical records and discuss nontechnical and technical aspects that constitute a reasonable security solution. It is argued that with guiding policy and current technology, an electronic medical record may offer better security than a traditional paper record.

Clinical workstations: An architectural prespective

The role of a clinical workstation is examined as an integral part of a larger, clinical information delivery and acquisition system. Different care scenarios and environmental factors influence the behavior of a workstation. The common functional components of a workstation are information resources, application logic and presentation. A workstation is successful when each of its components operates within an information architecture and contributes to meet user needs. New technologies to integrate and display information are making the workstation functions independent of the actual hardware and software platform.

Medical Informatics Training at Columbia University and the Columbia-Presbyterian Medical Center

The Department of Medical Informatics at Columbia University College of Physicians and Surgeons consists of a faculty of 17 full-and part-time faculty. The Department faculty collaborate with the Department of Computer Science and several clinical departments of the medical center. We offer courses in medical informatics, formal degrees (M.A., M.Phil. and Ph.D.) and a postdoctoral training program. In addition to academic offerings, the close affiliation with the Columbia-Presbyterian Medical Center and the primary responsibilities for clinical information systems offers trainees unique opportunities to work with and develop real-world applications. Faculty research programs include work on the Integrated Advanced Information Management System (IAIMS), Unified Medical Language System (UMLS), High-Perfor-mance Computing and Communications (HPCC), Electronic Medical Records, automated decision support and technology transfer through the Center for Advanced Technology.

Unlocking clinical data from narrative reports: a study of natural language processing

OBJECTIVE

To evaluate the automated detection of clinical conditions described in narrative reports.

DESIGN

Automated methods and human experts detected the presence or absence of six clinical conditions in 200 admission chest radiograph reports.

STUDY SUBJECTS

A computerized, general-purpose natural language processor; 6 internists; 6 radiologists; 6 lay persons; and 3 other computer methods.

MAIN OUTCOME MEASURES

Intersubject disagreement was quantified by "distance" (the average number of clinical conditions per report on which two subjects disagreed) and by sensitivity and specificity with respect to the physicians.

RESULTS

Using a majority vote, physicians detected 101 conditions in the 200 reports (0.51 per report); the most common condition was acute bacterial pneumonia (prevalence, 0.14), and the least common was chronic obstructive pulmonary disease (prevalence, 0.03). Pairs of physicians disagreed on the presence of at least 1 condition for an average of 20% of reports. The average intersubject distance among physicians was 0.24 (95% Cl, 0.19 to 0.29) out of a maximum possible distance of 6. No physician had a significantly greater distance than the average. The average distance of the natural language processor from the physicians was 0.26 (Cl, 0.21 to 0.32; not significantly greater than the average among physicians). Lay persons and alternative computer methods had significantly greater distance from the physicians (all > 0.5). The natural language processor had a sensitivity of 81% (Cl, 73% to 87%) and a specificity of 98% (Cl, 97% to 99%); physicians had an average sensitivity of 85% and an average specificity of 98%.

CONCLUSIONS

Physicians disagreed on the interpretation of narrative reports, but this was not caused by outlier physicians or a consistent difference in the way internists and radiologists read reports. The natural language processor was not distinguishable from the physicians and was superior to all other comparison subjects. Although the domain of this study was restricted (six clinical conditions in chest radiographs), natural language processing seems to have the potential to extract clinical information from narrative reports in a manner that will support automated decision-support and clinical research.

Decision support in healthcare

To address the recognized problems associated with information overload and limited human memory, computer-based systems which help healthcare providers use information to make better decisions have been developed and implemented. These decision aids are designed to improve the quality and reduce the cost of healthcare. Currently, the most widely used computer application is to simply provide needed facts about the patient in an organized and timely fashion. Additionally, healthcare workers can access literature, ask questions of aggregates of patient data for clinical or administrative decisions, receive warnings or suggestions when the patient's data satisfy certain logical rules receive critiques when proposing therapies or ordering diagnostic tests, receive guidelines for standards of care, access programs which analyze tradeoffs and likelihoods of alternative outcomes (decision analysis) and receive lists of differential diagnoses. Given this wonderful panoply of capabilities, the question becomes 'why aren't more people using these aids and what are the demonstrated benefits of such capabilities?' In this paper we review the types of decision aids which have been successfully implemented and the challenges to implementation (knowledge representation, connections to databases, need for comprehensive, coded databases and evaluation of benefits).

Computer-generated informational messages directed to physicians: effect on length of hospital stay

OBJECTIVE

With the advent of hospital payment by diagnosis-related group (DRG), length of stay (LOS) has become a major issue in hospital efforts to control costs. Because the Columbia-Presbyterian Medical Center (CPMC) has had above-average LOSs for many DRGs, the authors tested the hypothesis that a computer-generated informational message directed to physicians would shorten LOS.

DESIGN

Randomized clinical trial with the patient as the unit of randomization.

SETTING AND STUDY POPULATION

From June 1991 to April 1993, at CPMC in New York, 7,109 patient admissions were randomly assigned to an intervention (informational message) group and 6,990 to a control (no message) group.

INTERVENTION

A message giving the average LOS for the patient's admission or provisional DRG, as assigned by hospital utilization review, and the current LOS, in days, was included in the main menu for review of test results in the hospital's clinical information system, available at all nursing stations in the hospital.

MAIN OUTCOME MEASURE

Hospital LOS.

RESULTS

The median LOS for study patients was 7 days. After adjustment for covariates including age, sex, payor, patient care unit, and time trends, the mean LOS in the intervention group was 3.2% shorter than that in the control group (p = 0.022).

CONCLUSION

Computer-generated patient-specific LOS information directed to physicians was associated with a reduction in hospital LOS.

Medical Informatics Training at Columbia University and the Columbia-Presbyterian Medical Center

The Department of Medical Informatics at Columbia University College of Physicians and Surgeons consists of a faculty of 17 full- and part-time faculty. The Department faculty collaborate with the Department of Computer Science and several clinical departments of the medical center. We offer courses in medical informatics, formal degrees (M.A., M.Phil. and Ph.D.) and a postdoctoral training program. In addition to academic offerings, the close affiliation with the Columbia-Presbyterian Medical Center and the primary responsibilities for clinical information systems offers trainees unique opportunities to work with and develop real-world applications. Faculty research programs include work on the Integrated Advanced Information Management System (IAIMS), Unified Medical Language System (UMLS), High-Performance Computing and Communications (HPCC), Electronic Medical Records, automated decision support and technology transfer through the Center for Advanced Technology.

Medical decision support: experience with implementing the Arden Syntax at the Columbia-Presbyterian Medical Center

We began implementation of a medical decision support system (MDSS) at the Columbia-Presbyterian Medical Center (CPMC) using the Arden Syntax in 1992. The Clinical Event Monitor which executes the Medical Logic Modules (MLMs) runs on a mainframe computer. Data are stored in a relational database and accessed via PL/I programs known as Data Access Modules (DAMs). Currently we have 18 clinical, 12 research and 10 administrative MLMs. On average, the clinical MLMs generate 50357 simple interpretations of laboratory data and 1080 alerts each month. The number of alerts actually read varies by subject of the MLM from 32.4% to 73.5%. Most simple interpretations are not read at all. A significant problem of MLMs is maintenance, and changes in laboratory testing and message output can impair MLM execution significantly. We are now using relational database technology and coded MLM output to study the process outcome of our MDSS.

Internet as clinical information system: application development using the World Wide Web

Clinical computing application development at Columbia-Presbyterian Medical Center has been limited by the lack of a flexible programming environment that supports multiple client user platforms. The World Wide Web offers a potential solution, with its multifunction servers, multiplatform clients, and use of standard protocols for displaying information. The authors are now using the Web, coupled with their own local clinical data server and vocabulary server, to carry out rapid prototype development of clinical information systems. They have developed one such prototype system that can be run on most popular computing platforms from anywhere on the Internet. The Web paradigm allows easy integration of clinical information with other local and Internet-based information sources. The Web also simplifies many aspects of application design; for example, it includes facilities for the use of encryption to meet the authors' security and confidentiality requirements. The prototype currently runs on only the Web server in the Department of Medical Informatics at Columbia University, but it could be run on other Web servers that access the authors' clinical data and vocabulary servers. It could also be adapted to access clinical information from other systems with similar server capabilities. This approach may be adaptable for use in developing institution-independent standards for data and application sharing.

Integrated Advanced Medical Information Systems (IAIMS): payoffs and problems

IAIMS (Integrated Advanced Information Management Systems) is an initiative to improve the access to information needed to provide patient care, health-oriented education, biomedical research, and management of large medical center environments. This paper will review the goals, history, and accomplishments of the IAIMS initiative. Shortcomings and frustrations, lessons learned, and the future of such initiatives will also be discussed.

Encoding a post-operative coronary artery bypass surgery care plan in the Arden Syntax

The Arden Syntax for medical logic modules (Arden) was used to test the feasibility of encoding large, complex care plans. The critical portions of an existing paper-based care plan for the management of patients following coronary artery bypass graft (CABG) surgery were encoded in Arden and an X-windows user-interface was developed. The Arden Syntax proved adequate for encoding all of the necessary functions of the care plan. The limitations of the current Arden Syntax and possible additions to Arden are discussed.

Rationale for the Arden Syntax

The Arden Syntax, a language designed for writing and sharing task-specific knowledge for Medical Logic Modules (MLMs), has been recently accepted as a standard by the ASTM. The syntax is concerned with the critical task of sharing medical knowledge bases across many institutions. Because of the relative lack of agreement on vocabularies and data standards and because of the many other obstacles, the developers of the Arden Syntax took a pragmatic, straightforward approach that has borne fruit in a very short period of time. The syntax provides a vehicle for the health care community to begin sharing, so that we can see what works and what does not work, and we can begin to address the critical obstacles. In designing a language like the Arden Syntax, the authors make many decisions--but the final document gives only the result of these decisions without any explanation. By writing down the rationale behind the design of the syntax, we hope to aid users of the language, implementors of the language, and future designers of new languages.

Integrated Advanced Medical Information Systems (IAIMS): Payoffs and Problems

IAIMS (Integrated Advanced Information Management Systems) is an initiative to improve the access to information needed to provide patient care, health-oriented education, biomedical research, and management of large medical center environments. This paper will review the goals, history, and accomplishments of the IAIMS initiative. Shortcomings and frustrations, lessons learned, and the future of such initiatives will also be discussed.

Integrated Advanced Medical Information Systems (IAIMS): Payoffs and Problems

IAIMS (Integrated Advanced Information Management Systems) is an initiative to improve the access to information needed to provide patient care, health-oriented education, biomedical research, and management of large medical center environments. This paper will review the goals, history, and accomplishments of the IAIMS initiative. Shortcomings and frustrations, lessons learned, and the future of such initiatives will also be discussed.

Coping with changing controlled vocabularies

For the foreseeable future, controlled medical vocabularies will be in a constant state of development, expansion and refinement. Changes in controlled vocabularies must be reconciled with historical patient information which is coded using those vocabularies and stored in clinical databases. This paper explores the kinds of changes that can occur in controlled vocabularies, including adding terms (simple additions, refinements, redundancy and disambiguation), deleting terms, changing terms (major and minor name changes), and other special situations (obsolescence, discovering redundancy, and precoordination). Examples are drawn from actual changes appearing in the 1993 update to the International Classification of Diseases (ICD9-CM). The methods being used at Columbia-Presbyterian Medical Center to reconcile its Medical Entities Dictionary and its clinical database are discussed.

User comments on a clinical event monitor

Columbia-Presbyterian Medical Center's health care providers have access to alerts and interpretations generated by an Arden Syntax-based clinical event monitor. They have the opportunity to send comments to the clinical information services staff. Over a period of 26 months, they sent 126 comments. The comments were analyzed using the critical incident technique, resulting in a hierarchy of categories that summarizes user concerns. The majority of comments (65) indicated that the messages were actually (8) or at least potentially useful (57). A minority (28) indicated that they were unhelpful (27) or actually harmful (1). Another group (27) made suggestions or asked questions. The comments have been very helpful for the maintenance of Medical Logic Modules (MLMs) and the clinical event monitor itself.

IAIMS and sharing

The Integrated Academic Information Management System (IAIMS) concept is about sharing resources and information, and about improving the decision-making ability of health care professionals by integrating information. At Columbia-Presbyterian Medical Center, the IAIMS project has established an information architecture based on common, shared computing and networking resources. The institutional computing culture has been changed with increased sharing of information and, consequently, improved quality of information. Several classes of information in the areas of clinical, scholarly, administrative, basic research, and core resources have been identified for better understanding of information responsibility. Technical problems such as heterogeneity on workstation platforms and lack of universal syntactic and semantic standards for health care information exchange still impede inter-institutional sharing of information.

Mapping clinically useful terminology to a controlled medical vocabulary

We have mapped clinically used diagnostic terms from a legacy ambulatory care system to the separate controlled vocabulary of our central clinical information system. The methodology combines elements of lexical and morphologic text matching techniques, followed by manual physician review. Results of the automated matching algorithm before and after partial manual review are presented. The results of this effort will permit the migration of coded clinical data from one system to another. Output from the system after the term review process will be fed back to the target vocabulary via automated and semi-automated means to improve its clinical utility.

Knowledge-based approaches to the maintenance of a large controlled medical terminology

OBJECTIVE

Develop a knowledge-based representation for a controlled terminology of clinical information to facilitate creation, maintenance, and use of the terminology.

DESIGN

The Medical Entities Dictionary (MED) is a semantic network, based on the Unified Medical Language System (UMLS), with a directed acyclic graph to represent multiple hierarchies. Terms from four hospital systems (laboratory, electrocardiography, medical records coding, and pharmacy) were added as nodes in the network. Additional knowledge about terms, added as semantic links, was used to assist in integration, harmonization, and automated classification of disparate terminologies.

RESULTS

The MED contains 32,767 terms and is in active clinical use. Automated classification was successfully applied to terms for laboratory specimens, laboratory tests, and medications. One benefit of the approach has been the automated inclusion of medications into multiple pharmacologic and allergenic classes that were not present in the pharmacy system. Another benefit has been the reduction of maintenance efforts by 90%.

CONCLUSION

The MED is a hybrid of terminology and knowledge. It provides domain coverage, synonymy, consistency of views, explicit relationships, and multiple classification while preventing redundancy, ambiguity (homonymy) and misclassification.

Full-text document storage and retrieval in a clinical information system

The overall design of the CIS at CPMC is heavily influenced by the decision support component. The type of automated decision support being implemented dictates the need for highly structured or coded data. The value of decision support systems has been well documented. The current reliance on free-text documents is natural and a rewarding first step to a more valuable mix of coded and free text. While the health care provider might find the textual comments of the various reports extremely useful, the capability of an automated system to vigilantly review every data element for trends and anomalies is becoming invaluable in today's ever more complex health care delivery environment. Other approaches such as optical imaging systems would facilitate human decision support, but do not supply data in a format that can be processed by automated decision support systems. The developers of the CIS at CPMC believe that data are most valuable when available for both human and automated decision support.

Physician use of computers: is age or value the predominant factor?

One common explanation for the failure to achieve broad physician utilization of computer applications has been the suggestion that "We can't teach older individuals to use computers." To investigate this hypothesis, we examined utilization patterns for the Clinical Information System (CIS) at Columbia Presbyterian Medical Center (CPMC). We analyzed CIS usage for 925 attending physicians who were listed as an admitting or attending physician or surgeon for at least one patient during the year 1992. Sixty-one percent (561/925) of the attending physicians used the system at least once during the year. Sixty five percent (186/287) of the physicians who admitted at least 50 cases used the system at least 120 times during the year. The most surprising aspect of our analysis was that physicians in their late 60's and early seventies actually used the system more than their peers who were in their late 50's. Patterns of use by age group were similar for those who admitted many and few patients to the hospital. Using linear regression and chi squared analysis, we found that age is correlated (p < 0.002) with levels of physician use (inquiries per case), although age can explain (r-squared) only 3% of the observed variation in utilization patterns. We also found that there was significant variation in utilization (inquiries per case) by attendings in different departments (p < 0.007). However, the variation within departments was also large. We conclude that age and type of practice are statistically significant but not major factors in predicting which attendings will use the system. Growth rates over time (19% year to year increase in the average number of different users per day) indicate that, if present trends continue, virtually all physicians regardless of age will use the Clinical Information System for results review. We continue to feel that providing value, access and ease of use are the most important determinants for success.

Desperately seeking data: knowledge base-database links

Linking a knowledge-based system (KBS) to a clinical database is a difficult task, but critical if such systems are to achieve widespread use. The Columbia-Presbyterian Medical Center's clinical event monitor provides alerts, interpretations, research screening, and quality assurance functions for the center. Its knowledge base consists of Arden Syntax Medical Logic Modules (MLMs). The knowledge base was analyzed in order to quantify the use and impact of KBS-database links. The MLM data slot, which contains the definition of these links, had almost as many statements (5.8 vs. 8.8, ns with p = 0.15) and more tokens (122 vs. 76, p = 0.037) than the logic slot, which contains the actual medical knowledge. The data slot underwent about twice as many modifications over time as the logic slot (3.0 vs. 1.6 modifications/version, p = 0.010). Database queries and updates accounted for 97.2% of the MLM's total elapsed execution time. Thus, KBS-database links consume substantial resources in an MLM knowledge base, in terms of coding, maintenance, and performance.

ASTM E31.15 on health knowledge representation: the Arden Syntax

ASTM subcommittee E31.15 on Health Knowledge Representation was formed to promote standards for defining and sharing health knowledge bases. Its first standard, the Ardan Syntax, is focused on knowledge bases that can be represented as a set of independent modules called Medical Logic Modules (MLMs). The standard is in clinical use and has generated significant interest in industry and academics. The Extensions task group plans to extend the syntax where appropriate, to expand to other types of knowledge bases. The Validation/Verification task group is approaching the enormous problem of evaluating knowledge bases and the process of sharing them.

IAIMS at Columbia-Presbyterian Medical Center: accomplishments and challenges

The concept of "one-stop information shopping" is becoming a reality at Columbia-Presbyterian Medical Center. Our goal is to provide access from a single workstation to clinical, research, and library resources; university and hospital administrative systems; and utility functions such as word processing and mail. We have created new organizational units and installed a network of workstations that can access a variety of resources and systems on any of seventy-two different host computers/servers. In November 1991, 2,600 different individuals used the clinical information system, 700 different individuals used the library resources, and 900 different individuals used hospital administrative systems via the network. Over the past four years, our efforts have cost the equivalent of $23 million or approximately 0.5% of the total medical center budget. Even small improvements in productivity and in the quality of work of individuals who use the system could justify these expenditures. The challenges we still face include the provision of additional easy-to-use applications and development of equitable methods for financial support.

The integrated academic information management system at Columbia-Presbyterian Medical Center

Over the past seven years, Columbia-Presbyterian Medical Center has been planning and implementing an integrated academic information management system. Accomplishments to date include establishing an institutional information architecture, installing a campus-wide network of workstations, recruiting the staff needed to develop and implement the system, and developing various applications. This paper presents the rationale and steps involved in these accomplishments, as well as data on use of the system so far.

The MEDLINE Button

We have developed a computerized method for performing bibliographic searches directly from patient data involving five steps: 1) identifying specific patient data which raises a question in the mind of the user, 2) selection (from a list of generic questions) of a small number of questions which fit the selected patient data, 3) automated translation of the patient data into appropriate terms used for bibliographic indexing, 4) conversion of the question selected by the user into a search strategy, and 5) transfer of the search strategy to a search engine for a bibliographic database. We have modified the Columbia-Presbyterian Clinical Information System to experiment with this method. The first implementation converts patient diagnoses and procedures coded in ICD9-CM into Medical Subject Headings (MeSH) and searches Medline using BRS/Onsite. Challenges include development of a useful set of generic questions and translation from ICD9-CM to MeSH using the Unified Medical Language System (UMLS).

Network information security in a phase III Integrated Academic Information Management System (IAIMS)

The developing Integrated Academic Information System (IAIMS) at Columbia-Presbyterian Medical Center provides data sharing links between two separate corporate entities, namely Columbia University Medical School and The Presbyterian Hospital, using a network-based architecture. Multiple database servers with heterogeneous user authentication protocols are linked to this network. "One-stop information shopping" implies one log-on procedure per session, not separate log-on and log-off procedures for each server or application used during a session. These circumstances provide challenges at the policy and technical levels to data security at the network level and insuring smooth information access for end users of these network-based services. Five activities being conducted as part of our security project are described: (1) policy development; (2) an authentication server for the network; (3) Kerberos as a tool for providing mutual authentication, encryption, and time stamping of authentication messages; (4) a prototype interface using Kerberos services to authenticate users accessing a network database server; and (5) a Kerberized electronic signature.

Chest radiography: a tool for the audit of report quality

In a radiology department, clinical audit implies multiple readings of selected images to identify those findings that should be recognized and to document any departure from this standard for each radiologist. The authors developed an alternate approach for an audit on the basis of clinical outcomes collected in a medical computing facility. Techniques borrowed from information theory were used to measure the clinical information contributed by radiologists as they interpreted chest radiographs. The reported findings were evaluated in light of the discharge diagnosis. The scores generated quantified the information contributed to the final diagnosis by the radiologist's description. This audit approach was tested in a group of 100 chest radiographs. Significant differences were found in the mean scores for information contributed by five different readers. These differences were similar to differences demonstrated in audits by means of multiple readings of chest radiographs. These results support use of a form of audit that is substantially less expensive and time consuming than that typically used in radiology departments.

An initial assessment of the cost and utilization of the Integrated Academic Information System (IAIMS) at Columbia Presbyterian Medical Center

The concept of "one stop information shopping" is becoming a reality at Columbia Presbyterian Medical Center (CPMC). The goal of our effort is to provide access to university and hospital administrative systems as well as clinical and library applications from a single workstation, which also provides utility functions such as word processing and mail. Since June 1987, CPMC has invested the equivalent of $23 million dollars to install a digital communications network that encompasses 18 buildings at seven geographically separate sites and to develop clinical and library applications that are integrated with the existing hospital and university administrative and research computing facilities. During June 1991, 2425 different individuals used the clinical information system, 425 different individuals used the library applications, and 900 different individuals used the hospital administrative applications via network access. If we were to freeze the system in its current state, amortize the development and network installation costs, and add projected maintenance costs for the clinical and library applications, our integrated information system would cost $2.8 million on an annual basis. This cost is 0.3% of the medical center's annual budget. These expenditures could be justified by very small improvements in time savings for personnel and/or decreased length of hospital stay and/or more efficient use of resources. In addition to the direct benefits which we detail, a major benefit is the ease with which additional computer-based applications can be added incrementally at an extremely modest cost.