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Display Omitted Multiple models are used to evaluate clinical information system (CIS) satisfaction and continuance intention (CI).No single model appears sufficient in late post-adoption.System quality is a major direct and indirect determinant of satisfaction and continuance intention.The proposed UMISC metamodel can be adapted to each phase of CIS deployment. ContextPermanent evaluation of end-user satisfaction and continuance intention is a critical issue at each phase of a clinical information system (CIS) project, but most validation studies are concerned with the pre- or early post-adoption phases. ObjectiveThe purpose of this study was twofold: to validate at the Pompidou University Hospital (HEGP) an information technology late post-adoption model built from four validated models and to propose a unified metamodel of evaluation that could be adapted to each context or deployment phase of a CIS project. MethodsFive dimensions, i.e., CIS quality (CISQ), perceived usefulness (PU), confirmation of expectations (CE), user satisfaction (SAT), and continuance intention (CI) were selected to constitute the CI evaluation model. The validity of the model was tested using the combined answers to four surveys performed between 2011 and 2015, i.e., more than ten years after the opening of HEGP in July 2000. Structural equation modeling was used to test the eight model-associated hypotheses. ResultsThe multi-professional study group of 571 responders consisted of 158 doctors, 282 nurses, and 131 secretaries. The evaluation model accounted for 84% of variance of satisfaction and 53% of CI variance for the period 2011-2015 and for 92% and 69% for the period 2014-2015. In very late post adoption, CISQ appears to be the major determinant of satisfaction and CI. Combining the results obtained at various phases of CIS deployment, a Unified Model of Information System Continuance (UMISC) is proposed. ConclusionIn a meaningful CIS use situation at HEGP, this study confirms the importance of CISQ in explaining satisfaction and CI. The proposed UMISC model that can be adapted to each phase of CIS deployment could facilitate the necessary efforts of permanent CIS acceptance and continuance evaluation.

The increasing costs of health care and the economic reality has produced an interesting paradox for the health professional to perform more clinical work with fewer support personnel. Moreover, an explosion of the knowledge-base that underlies sound clinical care not only makes effective time management critical, but also knowledge management compelling. A multimedia workstation is an electronic assistant for the busy health professional that can help with administrative tasks and give access to clinical information and knowledge networks. The multimedia nature of processed information reflects an evolution of medical technologies that involve more and more complex objects such as video sequences or digitized signals. Analysis of the 445 Medline-indexed publications for the January 1991 to December 1994 period, that included the word "workstation" either in their title or in their abstract, helps in refining objectives and challenges both for health professionals and decision makers. From an engineering perspective, development of a workstation requires the integration into the same environments of tools to localize, access, manipulate and communicate the required information. The long-term goal is to establish an easy access in a collaborative working environment that gives the end-user the feeling of a single virtual health enterprise, driven by an integrated computer system when the information system relies on a set of heterogeneous and geographically distributed components. Consequences in terms of migration from traditional client/server architectures to more client/network architectures are considered.

Most medical schools in France have chairs in Biostatistics and Medical Informatics to coordinate the teaching of these two disciplines both within the regular curriculum of the medical studies and as a specialized teaching. This paper describes the current medical informatics specialized program offered at the Paris Universities. Since 1968 the program has comprised a Master of Science and a Ph.D. degree. At the Master Level, despite several reforms and in-depth program revisions, the curriculum is still organized as a set of modules of 100 hours teaching with a large freedom for the medical faculties to define the contents of the courses and for the students to organize their studies and combine medical informatics, biomathematics and biostatistics training. Since 1990, an intensive one-year full-time course is offered, called Advanced Study Diploma in Medical Informatics, which is strongly research oriented. This program seems a good strategy to form medical informatics specialists who have initially received a broader education in informatics and statistics.

Summary Objectives: Several alert systems have been developed to improve the patient safety aspects of clinical information systems (CIS). Most studies have focused on the evaluation of these systems, with little information provided about the methodology leading to system implementation. We propose here an ‘agile’ business rule design framework (BRDF) supporting both the design of alerts for the validation of drug prescriptions and the incorporation of the end user into the design process. Methods: We analyzed the unified process (UP) design life cycle and defined the activities, subactivities, actors and UML artifacts that could be used to enhance the agility of the proposed framework. We then applied the proposed framework to two different sets of data in the context of the Georges Pompidou University Hospital (HEGP) CIS. Results: We introduced two new subactivities into UP: business rule specification and business rule instantiation activity. The pharmacist made an effective contribution to five of the eight BRDF design activities. Validation of the two new subactivities was effected in the context of drug dosage adaption to the patients’ clinical and biological contexts. Pilot experiment shows that business rules modeled with BRDF and implemented as an alert system triggered an alert for 5824 of the 71,413 prescriptions considered (8.16%). Conclusion: A business rule design framework approach meets one of the strategic objectives for decision support design by taking into account three important criteria posing a particular challenge to system designers: 1) business processes, 2) knowledge modeling of the context of application, and 3) the agility of the various design steps.

Cell fractions highly enriched either for monocytes of for B lymphocytes were separated from human peripheral blood. They were tested for their capacity to stimulate allogeneic lymphocytes in mixed leukocyte cultures, using dose-response titrations. Neither population could be stimulated to proliferate by allogeneic cells, but both proved strong stimulators. In this respect monocytes were more efficient than B cell preparations. Differences were pronounced at the lower numbers of stimulating cells but were no longer significant with large amounts of cells.

Objective. The aim of this study was to evaluate the relevance of the signals generated by a computerized drug - drug inter- action detection system and to design a classification of overridden drug -drug interaction alerts. Study Design. Prospective study over two months. Setting. Five hundred and ten-bed university paediatric hospital. Main Outcome Measures. In Robert DebreHospital physicians generate drug orders online using a computerized physician order entry system that also detects drug - drug interactions in real time. We analysed the relevance of a sample of alerts over- ridden by physicians. Results. We analysed a sample of 613 overridden alerts. We defined three categories of overridden alerts: informational errors (35); system errors (244) and accurate alerts (334). Two reasons account for 40% of false-positive alerts: an inability of the system to recognize real conflicts between drug treatments and guidelines stating that the two drugs can be used together, because the benefit outweighs the risk of side effects due to the drug - drug interaction. Conclusions. We created a classification of overridden alerts, in the context of computerized physician order entry system coupled with a drug - drug interaction detection system. There is clearly room for improvement in the development of drug - drug interaction software. This classification should make it possible to break this work down into smaller tasks, making it possible to decrease the sensitivity to background noise of drug - drug interaction detection systems.

This article will appear in the next few weeks

International audience; Background and Objective : While risk of acute kidney injury (AKI) is a well documented adverse effect of some drugs, few studies have assessed the relationship between drug–drug interactions (DDIs) and AKI. Our objective was to develop an algorithm capable of detecting potential signals on this relationship by retrospectively mining data from electronic health records.Material and methods : Data were extracted from the clinical data warehouse (CDW) of the Hôpital Européen Georges Pompidou (HEGP). AKI was defined as the first level of the RIFLE criteria, that is, an increase ≥50 % of creatinine basis. Algorithm accuracy was tested on 20 single drugs, 10 nephrotoxic and 10 non-nephrotoxic. We then tested 45 pairs of non-nephrotoxic drugs, among the most prescribed at our hospital and representing distinct pharmacological classes for DDIs.Results : Sensitivity and specificity were 50 % [95 % confidence interval (CI) 23.66–76.34] and 90 % (95 % CI 59.58–98.21), respectively, for single drugs. Our algorithm confirmed a previously identified signal concerning clarithromycin and calcium-channel blockers (unadjusted odds ratio (ORu) 2.92; 95 % CI 1.11–7.69, p = 0.04). Among the 45 drug pairs investigated, we identified a signal concerning 55 patients in association with bromazepam and hydroxyzine (ORu 1.66; 95 % CI 1.23–2.23). This signal was not confirmed after a chart review. Even so, AKI and co-prescription were confirmed for 96 % (95 % CI 88–99) and 88 % (95 % CI 76–94) of these patients, respectively.Conclusion : Data mining techniques on CDW can foster the detection of adverse drug reactions when drugs are used alone or in combination.

Resume Introduction L'objectif de l'article est de presenter le nouveau paradigme pour la pratique medicale qui emerge depuis une dizaine d'annees : la medecine basee sur le niveau de preuve. Actualites et points forts Ce paradigme propose de nouveaux comportements pour les medecins, en limitant le role de l'intuition et de l'empirisme dans la pratique, et en utilisant les connaissances etablies par la science et publiees par la litterature scientifique. Perspectives et projets L'article presente les principales caracteristiques de cette demarche qui amene des questions importantes sur l'evolution de la pratique medicale et la validite de ce paradigme.

Hospital information systems (HIS) are computer systems designed to ease the management of all the hospital’s medical and administrative information and to improve the quality of health care. After a brief historical review, this chapter describes the overall strategy to select, deploy and then evaluate the deployed solution. Clear IT governance and IT alignment strategies are prerequisite to HIS deployment success. Emphasis is put on business process analysis/reengineering to select the business components which integration will constitute the overall HIS. In the clinical domain, main business components include the Patient Identification (PID), Admission/Discharge/Transfer (ADT), the electronic health record (EHR), the computerized provider order entry (CPOE) and the resource and appointment scheduling (AS) systems. Deployment phases are considered from basic ancillary services to integration into broader system and HIS data reuse for research. HIS return on investment (ROI) is described from a clinical, organizational and financial point of view.

This chapter will provide a brief history of the birth and development of medical informatics, followed by a description of its principal domains. These domains include bioinformatics, which relates to molecular and cellular aspects of medicine, clinical informatics, which deals with patient data and medical knowledge relating to the care of individual patients, and public health informatics, which brings together the tools, techniques and applications for reasoning at the population level. Links with other disciplines, including subdisciplines of computer sciences, biostatistics and biomedical engineering, have also been developed. There are many scientific societies for medical informatics, operating at the national, continental and international levels. These societies are presented here, together with the principal journals, scientific conferences and exhibitions in this field.

Phenome-Wide Association Studies (PheWAS) investigate whether genetic polymorphisms associated with a phenotype are also associated with other diagnoses. In this study, we have developed new methods to perform a PheWAS based on ICD-10 codes and biological test results, and to use a quantitative trait as the selection criterion. We tested our approach on thiopurine S-methyltransferase (TPMT) activity in patients treated by thiopurine drugs. We developed 2 aggregation methods for the ICD-10 codes: an ICD-10 hierarchy and a mapping to existing ICD-9-CM based PheWAS codes. Eleven biological test results were also analyzed using discretization algorithms. We applied these methods in patients having a TPMT activity assessment from the clinical data warehouse of a French academic hospital between January 2000 and July 2013. Data after initiation of thiopurine treatment were analyzed and patient groups were compared according to their TPMT activity level. A total of 442 patient records were analyzed representing 10,252 ICD-10 codes and 72,711 biological test results. The results from the ICD-9-CM based PheWAS codes and ICD-10 hierarchy codes were concordant. Cross-validation with the biological test results allowed us to validate the ICD phenotypes. Iron-deficiency anemia and diabetes mellitus were associated with a very high TPMT activity (p = 0.0004 and p = 0.0015, respectively). We describe here an original method to perform PheWAS on a quantitative trait using both ICD-10 diagnosis codes and biological test results to identify associated phenotypes. In the field of pharmacogenomics, PheWAS allow for the identification of new subgroups of patients who require personalized clinical and therapeutic management., Author Summary The use of underlying molecular mechanisms and other factors to describe and classify diseases is a major challenge for future treatment strategies. New methods are needed to achieve this goal. The phenome wide association study (PheWAS) methodology was initially developed to unveil unknown associations between a specific genetic status and phenotypic features (e.g. diagnoses from electronic health records). We initially propose to extend this method to assessment of the relationships between the levels of a quantitative trait and diagnosis codes. We also assess the relationships between this quantitative trait and the biological test results. We tested this method using the levels of enzymatic activity of thiopurine S-methyltransferase (TPMT) that is involved in the metabolism of thiopurine drugs used in inflammatory bowel diseases for example. We discovered an association between a very high TPMT activity and nutritional anemia and diabetes. These results could be used to describe a new subgroup of patients in order to optimize drug treatments.

The increasing costs of health care and the economic reality has produced an interesting paradox for the health professional to perform more clinical work with fewer support personnel. Moreover, an explosion of the knowledge-base that underlies sound clinical care not only makes effective time management critical, but also knowledge management compelling. A multimedia workstation is an electronic assistant for the busy health professional that can help with administrative tasks and give access to clinical information and knowledge networks. The multimedia nature of processed information reflects an evolution of medical technologies that involve more and more complex objects such as video sequences or digitized signals. Analysis of the 445 Medline-indexed publications for the January 1991 to December 1994 period, that included the word “workstation” either in their title or in their abstract, helps in refining objectives and challenges both for health professionals and decision makers. From an engineering perspective, development of a workstation requires the integration into the same environments of tools to localize, access, manipulate and communicate the required information. The long-term goal is to establish an easy access in a collaborative working environment that gives the end-user the feeling of a single virtual health enterprise, driven by an integrated computer system when the information system relies on a set of heterogeneous and geographically distributed components. Consequences in terms of migration from traditional client/server architectures to more client/network architectures are considered.

Apres avoir lu ce chapitre, vous devriez : pouvoir expliquer ce qu’est l’informatique medicale ; connaitre les principaux liens existant entre l’informatique medicale et differents autres domaines scientifiques ou medicaux comme l’informatique generale, la biostatistique, le genie biomedical ; pouvoir citer les principales associations et societes savantes nationales et internationales en informatique medicale ; connaitre les principaux journaux et congres internationaux servant aux chercheurs du domaine a communiquer leurs resultats et les modalites de soumission d’articles et de communication ; connaitre quelques structures de recherche et de financement de la recherche en informatique medicale.

Apres avoir lu ce chapitre, vous devriez : pouvoir expliquer quels sont les objectifs d’un systeme d’information hospitalier et lister les principales fonctions pouvant faire l’objet d’une informatisation ; savoir analyser la circulation, dans un hopital, des informations relatives aux examens biologiques ou radiologiques et connaitre les principales etapes qui peuvent beneficier au mieux d’une informatisation, d’une automatisation ; savoir analyser la circulation, dans un hopital, des informations relatives aux prescriptions therapeutiques ; quelles etapes peuvent beneficier au mieux d’une informatisation, d’une automatisation ? pouvoir citer les principaux sous systemes et ensembles de fonctions d’un SIH ; pouvoir citer les avantages et les inconvenients des architectures horizontales (par processus metier), verticales (par structures) et mixtes ; pouvoir citer les benefices que l’on peut attendre d’un systeme d’information hospitalier ; savoir quels sont les principaux problemes lies a la mise en oeuvre d’un SIH.

Most medical schools in France have chairs in Biostatistics and Medical Informatics to coordinate the teaching of these two disciplines both within the regular curriculum of the medical studies and as a specialized teaching. This paper describes the current medical informatics specialized program offered at the Paris Universities. Since 1968 the program has comprised a Master of Science and a Ph.D. degree. At the Master Level, despite several reforms and in-depth program revisions the curriculum is still organized as a set of modules of 100 hours teachins with a large freedom for the medical faculties to define the contents of the courses and for the students to organize their studies and combine medical informatics, biomathematics and biostatistics training. Since 1990, an intensive one-year full-time course is offered, called Advanced Study Diploma in Medical Informatics, which is strongly research oriented. This program seems a good strategy to form medical informatics special1 ists who have initially received a broader education in informatics and statistics.

The analysis of medical narratives and the generation of natural language expressions are strongly dependent on the existence of an adequate representation language. Such a language has to be expressive enough in order to handle the complexity of human reasoning in the domain. Sowa’s Conceptual Graphs (CG) are an answer, and this paper presents a multilingual implementation, using French, English and German. Current developments demonstrate the feasibility of an approach to natural Language Understanding where semantic aspects are dominant, in contrast, to syntax driven methods. The basic idea is to aggregate blocks of words according to semantic compatibility rules, following a method called Proximity Processing. The CG representation is gradually built, starting from single words in a semantic lexicon, to finally give a complete representation of the sentence under the form of a single CG. The process is dependent on specific rules of the medical domain, and for this reason is largely controlled by the declarative knowledge of the medical Linguistic Knowlege Base.

This paper describes the approach of the European HELIOS project to integrate image processing tools into ward information systems. The image processing tools are the result of the basic research in image analysis in the Department Medical and Biological Informatics at the German Cancer Research Center. These tools for the analysis of two-dimensional images and three-dimensional data volumes with 3D reconstruction and visualization are part of the Image Related Services of HELIOS. The HELIOS software engineering environment allows to use the image processing functionality in integrated applications.

The authors present a fuzzy classification procedure based on a well known fuzzy pattern matching technique (H. Dubois et al., Fuzzy Sets and Systems, vol. 28, p. 313-33, 1988). This procedure has been developed in order to diagnose the visual type of a lesion from 2D and static renal artery angiograms. In the implemented model, each observed lesion no longer belongs entirely to only one class (a specific visual type) but rather to all classes, with differing membership values. Here, the authors first place this concept in the general framework of computer systems that take imprecision and uncertainty into account in medical reasoning. They then present the method that they have developed in the specific context of diagnosing renal artery lesions and they describe the classification procedure itself, which is derived from Dubois et al. >

The aim of the HELIOS project is to create an integrated Software Engineering Environment (SEE) to facilitate the development and maintenance of medical applications. HELIOS is made of a set of software components, communicating through a software bus called the HELIOS Unification Bus. The object oriented paradigm is used both as the basic structure for building the software components and as the methodology for modelling, storing and retrieving the entities and procedures used in an application. Development standards include UNIX as operating system and X Window/MOTIF as windowing environment. One of the target applications for the HELIOS prototype is the development of a multimedia medical workstation as a front end to a hospital information system.

The health care professional workstation is a window to a heterogeneous set of functions that need to be ported to various types of hardware for different types of users. Processing aspects, which belong with the interface, storage and communication, to the architectural dimension of the workstation should not be considered outside of a more comprehensive model including the user, function and time dimensions. Several recommendations, which could provide the appropriate environment for development and help maintain a viable approach as the variables change along the four dimensions of the workstation model, are proposed. They concern the adaptation of the enterprise infrastructure to integrate workstations, the need for a reference architecture for health care workstation development and recommendations for the evaluation and dissemination of results.

The development of large-scale, clinically accepted decision support systems (DSS) calls for powerful and commonly available methods and tools for knowledge acquisition, system realisation, and knowledge base maintenance. The paper addresses problems associated with the integration of knowledge-based systems within the clinical setting with special reference to (i) data driven decision support, (ii) the Arden Syntax as a knowledge representation format and, (iii) the HELIOS software engineering environment. Architecture of a DSS based on Arden Syntax and its integration in the HELIOS environment are presented. Realisation of the DSS is discussed in relation to client-server architecture and object-oriented databases, which are essential concepts of the HELIOS environment. Sharability and reusability of the knowledge, together with commonality of used software tools are also discussed.

The most important part of alarm systems is the rules set that allows triggering alerts. We propose a generic rule design framework which can support the design and the implementation of alerts for drug prescriptions or their pharmaceutical validation. Our approach takes into account two important criteria, which represent two real challenges for the system designers. First, the developer needs to identify and model both users’ requirements and business processes in which the alarm system works. Second, the developer needs to model the knowledge associated with the decision rules with an appropriate language. We show how the Unified Process helps to model the business process for pharmaceutical validation. Knowledge representation benefited from use of SBVR, a language dedicated to rule representation within an object oriented framework. After a successful implementation of a prototype we plan to integrate such system within the hospital information system of the Georges Pompidou hospital.

Two fuzzy approaches to medical decision making are discussed and applied. In the first method a fuzzy rule-based approach is used to define the state of a hypertensive patient. The second approach, based on the distances between fuzzy numbers representing norm, pathology and experimental observations, is applied to peripheral neuropathy electrodiagnosis in diabetic patients. The examples deal with conveying a precise description of patient state to the physician, as a decision aid. Both approaches define patient state as a continuous variable, are robust, appear not to depend on the shape of membership function, can be used with dependent parameters and may easily be extended to other cases of medical categorization. >

Medical decision making is one of the most difficult daily tasks for physicians. Guidelines have been designed to reduce variance between physicians in daily practice, to improve patient outcomes and to control costs. In fact, few physicians use guidelines in daily practice. A way to ease the use of guidelines is to implement computerised guidelines (computer reminders). We present in this paper a method of computerising guidelines. Our objectives were: 1) to propose a generic model that can be instantiated for any specific guidelines; 2) to use eXtensible Markup Language (XML) as a guideline representation language to instantiate the generic model for a specific guideline. Our model is an object representation of a clinical algorithm, it has been validated by running two different guidelines issued by a French official Agency. In spite of some limitations, we found that this model is expressive enough to represent complex guidelines devoted to diabetes and hypertension management. We conclude that XML can be used as a description format to structure guidelines and as an interface between paper-based guidelines and computer applications.

Assessment of cardiovascular risk is widely proposed as a basis for taking management decisions about patients presenting with hypertension or hypercholesterolemia. Our aim was to critically assess the use of risk equations derived from epidemiological studies for the purpose of identifying high-risk patients. Risk equations were retrieved from the MEDLINE database and then applied to a data set of 118 patients. This data set was an evaluation study of the clinical value of the World Health Organization 1993 hypertension guidelines for the decision to treat mild hypertensive patients. We calculated agreement: 1) between equations and 2) between equations and the decision to treat taken by the physician. Most models were not applicable to our population, mainly because the original population had a narrow age range or comprised only males. Between-model agreement was better for the lower and upper risk quintiles than for the three other risk quintiles (0.58, 0.33, 0.34, 0.45, 0.70, from the lower to the upper risk quintile). When using an arbitrary threshold for defining high-risk patients (i.e.2% per year), we observed a huge variation of the proportion of patients classified at high risk (from 0 to 17%). There was a poor agreement between risk models and the decision to treat taken by the physician. These results suggest that risk-based guidelines should be validated before their diffusion.

Data coming from the French national statistics on the cause of deaths are used to calculate the probabilities of death from pathologies. These probabilities are calculated according to age, sex, and place of residence of the patient to “personalize” the estimate. This individual prediction of the risk of death is proposed for pathologies for which the feasibility and the utility of prevention measures had been demonstrated. Relative risks of death according to the socioprofessional category, which are coming from the scientific literature, are used to adjust the probabilities of death as a function of the patient socioprofessional category. The aim of this work is to guide a scientist toward a prevention strategy according to the age and characteristics of patient. The use of computers by the scientists will make possible the diffusion of such tool of prediction to improve a personalized prevention.

Interoperability is a key issue and a long-term domain of research for distributed healthcare information systems. The European project SynEx provides an open and standard integration platform for both new and legacy medical applications. It allows the collaboration of distributed and heterogeneous healthcare records and services. It aims to provide access to Hospital Information Services, to remote sources of medical data and to medical knowledge, in a seamless way, hiding the distribution aspects and the heterogeneity of systems. In this project, the Medical Informatics Department of the Broussais University Hospital is responsible for the development of the "Mediator Service". It is a software component of the SynEx platform which is used as a "glue" mechanism to provide a flexible way to facilitate the interchange between any pair of systems, with different nomenclatures and data structures. The Mediator Service uses a generic model of mediators to create, through specialization, specific mediators for practical cases. Based on this model, it offers a C++ library to be used as the tool case by the programmers, to reduce the development effort. The use of XML as a powerful data interchange format and as a data structure descriptor is proposed and evaluated.

The paper presents the new paradigm for medical practice which has been emerging for a decade: evidence-based medicine.The paradigm proposes new skills for the physicians, de-emphasizing intuition and empiricism in medical practice, and proposes the intensive use of medical literature for the medical practice.The article presents the main characteristics of the approach which is raising new important questions about the evolution of medical practice and the validity of the paradigm.

Our purpose was to analyze interobserver variability in the interpretation of renal digital subtraction angiography and to describe the main factors associated with observer discrepancies.Forty-nine cases of unilateral atheromatous renal artery stenosis of more than 60% were quantified first by local investigators in a multicenter study and then by five other radiologists. Differences between radiologists for the minimum diameter (Dmin), the reference diameter (Dref), and the percentage of stenosis of the renal arteries were analyzed. Interpretations by the local investigators were then compared with the gold standard, defined as the mean for the five radiologists.The average SD for estimation of all renal artery stenoses by all radiologists was 7% for stenosis percentage, 0.5 mm for Dmin, and 0.7 mm for Dref. Main discrepancies occurred more frequently in cases of weakly opacified renal artery stenosis and poststenotic dilatation. The observations of local investigators disagreed by more than two SDs (14%) with the gold standard for 11 of 49 cases (22%).The accuracy of digital subtraction angiography in renal artery interpretations is poor because of variations in evaluating both Dmin and Dref. Precise and reproducible methods for quantification of renal artery stenosis are required.

Risks and benefits of anticoagulant therapy depend directly of the quality of anticoagulation. We performed a meta-analysis of published randomized trials to assess the overall effectiveness of computer-based prescription systems on the quality of anticoagulation.Randomized controlled trials were identified through electronic searches of the Medline database (1966-1997) and systematic analyses of the references of articles. Two investigators selected relevant papers and summarized data from the studies.The outcome variable was the proportion of days within the target range of anticoagulation. A pooled estimate of the common odds ratio of being in the target range and its confidence interval was obtained by the Mantel-Haenszel method.Seven trials having included 1217 patients were identified. Computer systems were based on a pharmacokinetic-pharmacodynamic model and a bayesian prediction method. Most of them concerned the oral anticoagulant warfarin. The global odds ratio of being in the target range was 1.58 [95% CI: 1.34-1.86], thus meaning that the use of a computer for anticoagulation optimization increased by 58% the proportion of visits where patients were appropriately treated. The proportion of clinical events was too low for allowing a summary analysis.Evidence from randomized controlled trials supports the effectiveness of computer-aided anticoagulant prescription. Diffusion of these systems in ambulatory care could increase the benefit/risk ratio of anticoagulant treatment at a low cost.

Clinicians regularly confront dilemmas when ordering and interpreting diagnostic tests. This paper presents the basic principles necessary for the critical appraisal of articles about diagnostic tests. Basic notions such as sensitivity and specificity are defined. The advantages of using the newer notion of likelihood ratios are underlined. Since all these quantities are estimates of unknown true values, the method for calculating confidence intervals are reported. Finally, the simplified expression of Bayes' theorem based on the use of likelihood ratios is described alongside with a simple nomogram making it possible to calculate posttest probabilities at the bedside.

The health professional multimedia workstation is the natural entry point to health and knowledge networks. It should allow an easy and transparent management of all the data necessary for patient management. Multimedia nature of processed information reflects evolution of medical techniques that involve more and more complex objects such as video sequences or digitized signals. Workstations can be considered from 3 points of view: the professional end-users, the developers and the decision makers. The long term goal for the end-user is to establish an easy access in a working environment, that gives him/her the feeling of a single comprehensive application running on a single computer when the information system relies on a set of heterogeneous and geographically distributed components. Development of a workstation requires the integration into the same environment of tools to localize, access, manipulate and communicate the required information within a health information network. Analysis of the 445 Medline-indexed publications for the January 1991 to December 1994 period, that included the word workstation either in their title or in their abstract, helps in refining objectives and challenges both for the health professionals and the decision makers.

This paper describes the integration of a European Image Processing System with an existing American Hospital Information System. Both systems were built independently (with no knowledge of each other), but on open systems standards. The easy integration of these systems demonstrates the major benefit of open standards-based software design.