Why GPs do not follow computerized guidelines: an attempt of explanation involving usability with ASTI guiding mode.

Clinical decision support systems (CDSSs) have the potential to increase guideline adherence, but factors of success are not well understood. ASTI-GM is an on demand guideline-based CDSS where the user interactively characterizes her patient by browsing the system knowledge base to obtain the recommended treatment. We conducted a web-based evaluation of ASTI-GM as a before-after study to assess whether the system improves general practitioners' (GPs) performance and how they would use it. Five clinical cases had to be solved, as usual in the before phase, and using ASTI-GM in the after phase. On a 2-month period, 266 GPs participated and 1,981 prescription orders were collected. The overall guideline adherence rate increased from 27.2% to 64.3%. Only 56.4% of ASTI-GM uses corresponded to a "good use" of the system. Adherence increased from 28.5% to 86.1% in the sub-group of "good uses", whereas it only increased from 28.1% to 36.6% in the complementary sub-group. Reasons for non "good uses" of CDSSs should be investigated since they impede their potential impact.

Role of physicians' reactance in e-iatrogenesis: a case study with ASTI guiding mode on the management of hypertension.

Clinical decision support systems (CDSSs) have the potential to increase guideline adherence, but factors of success are not yet understood. ASTI guiding mode (ASTI-GM) is an on-demand guideline-based CDSS where the user navigates in a knowledge base to get the best treatment for a given patient. We conducted a web-based evaluation of ASTI-GM, carried out as a before-after study, where general practitioners (GPs) were asked to solve 5 clinical cases, first without ASTI-GM, then using the system. Of the 136 GPs that resolved the case on the management of hypertension, compliance with best practices increased from 69.1% to 80.9% with ASTI-GM. When the navigation matched the set of patient parameters described in the clinical case, the increase was even higher and reached 92.9%. E-iatrogenesis has been measured at 19.1%, with 5.1% of commission errors, 8.1% of negative reactance, and 5.9% of neutral reactance. Role of physicians' reactance in noncompliance with guideline-based CDSSs should be further investigated.

Component-based mediation services for the integration of medical applications.

Allowing exchange of information and cooperation among network-wide distributed and heterogeneous applications is a major need of current health-care information systems. The European project SynEx aims at developing an integration platform for both new and legacy applications on each partner's site. We developed, in this project, mediation services based on the generic and reusable software components that facilitate the construction of an integration platform and ease the communication and the meaningful transformation among distributed and heterogeneous applications. The main component of the mediation services is named Pilot, which serves as an intelligent broker. It uses a multi-agents service model allowing the integration platform to be multi-servers. It transforms a client request into a valid high level service on the platform. Each service is broken up into several elementary steps by the Pilot. For each step, the Pilot uses an agent to realize the operation configured by the step. At runtime, the Pilot synchronizes the execution of different steps. To ease the communication and the interaction with the heterogeneous systems, an agent can integrate a Mediator. The Mediators are the communication and interpretation tools within the mediation services. We have developed a generic model that can be specialized for creating specific mediators for the different use cases. The mediator model uses two interfaces to connect the mediator with two systems that need to communicate. Each interface deals with the three aspects through three managers (the Communication Manager, the Syntax Manager and the Semantic Manager). Some ready-to-use specializations are developed for some well defined cases which can reduce the development effort. Once a manager is specialized, it can be used in different combinations with other managers to resolve different problems. The meaningful transformation is ensured on a semantic level in each mediator through the Semantic Model component. This last component allows the mapping among different vocabularies used by different systems through a shared ontology which allows the mapping process to focus on the meaning of the transformed information. We have used XML in different components of the mediation services as the interchange format and the description format. This has enhanced the flexibility of the components. The component based approach allows the generic components to be reused in different contexts and also allows the mediations services to be open to integrate other available technologies thus largely reduce the development efforts.

"THE PILOT": a tool for connecting existing HIS to an extranet quickly, easily and smoothly.

Migrations and expansions of information systems are constantly at the front line of all the computer science problems to be overcome in medical / health informatics systems. It is shown here that one effective way to open the communication between heterogeneous systems is depending upon the ease of putting all the systems at work together using the middleware level to facilitate the interconnection between heterogeneous applications. However the most difficult application to migrate is certainly the ADT. It is shown here how the Pilot could facilitate the migration of applications namely with the migration of the ADT itself from a centralized platform to a full scale distributed system. Indeed the Pilot has been developed up to the stage of a pre-product and is on sale already. It has been experienced satisfactorily and is presented here.

Integrating medical applications in an open architecture through generic and reusable components.

Allowing exchange of information and cooperation among network-wide distributed and heterogeneous applications is a major need of current health care information systems. It forces the development of open and modular integration architectures. Major issues in the development include defining a flexible and robust federation model, developing interaction and communication facilities as well as the mechanism insuring semantic interoperability. We developed generic and reusable software components to ease the construction of any integration platform. The Pilot and the Mediator Service components facilitate the execution of services and the meaningful transformation of information. They have been tested in the context of the SynEx European project to construct a multi-agents based integration architecture. The possibility of such architectures to take into account the issue of semantic interoperability is further discussed.

Integration of medical applications: the 'mediator service' of the SynEx platform.

Interoperability is a key issue and a long-term domain of research for distributed healthcare information systems. The SynEx European project provides open and standard integration platform for both new and legacy medical applications. It aims to provide access to hospital information services, patient records, and to medical knowledge, in a seamless way, hiding the distribution aspects and the heterogeneity of the underlying systems. In this study, we describe the SynEx 'mediator service', a software engineering component, that is used to facilitate the development of mediators between any pair of SynEx components and to manage the corresponding interchange messages. Both a C++ library and a Java package of a generic mediator model are provided with several ready-to-use specialisations for well-defined use. The use of the XML technology as a powerful data interchange format and as an efficient data structure converter is proposed and discussed.

Towards specialised middleware for healthcare information systems.

Middleware is now a commonly used expression and anyone building distributed applications is referring to 'middleware services'. Nevertheless this notion lacks of sound theoretical foundation. This paper tries to clarify the relationship between the components of distributed environments, especially in healthcare and to establish some classification aiming at gaining a common understanding of the functionality and interdependency of the existing modules of distributed environments. A case study is presented and the potential benefits of using a middleware approach are discussed.

The "mediator service", a component to ease the integration of medical applications in the SynEx framework.

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.

Rationale and design considerations for a semantic mediator in health information systems.

Rapid development of community health information networks raises the issue of semantic interoperability between distributed and heterogeneous systems. Indeed, operational health information systems originate from heterogeneous teams of independent developers and have to cooperate in order to exchange data and services. A good cooperation is based on a good understanding of the messages exchanged between the systems. The main issue of semantic interoperability is to ensure that the exchange is not only possible but also meaningful. The main objective of this paper is to analyze semantic interoperability from a software engineering point of view. It describes the principles for the design of a semantic mediator (SM) in the framework of a distributed object manager (DOM). The mediator is itself a component that should allow the exchange of messages independently of languages and platforms. The functional architecture of such a SM is detailed. These principles have been partly applied in the context of the HELIOS object-oriented software engineering environment. The resulting service components are presented with their current state of achievement.

Middleware for healthcare information systems.

Middleware is now a commonly used expression and anyone building distributed applications is referring to "middleware services". Nevertheless this notion lacks of sound theoretical foundation. This paper tries to clarify the relationship between the components of distributed environments, especially in healthcare, and to establish some classification aiming at gaining a common understanding of the functionalities and interdependency of the existing modules of distributed environments.

Legacy systems: managing evolution through integration in a distributed and object-oriented computing environment.

Legacy systems are crucial for organizations since they support key functionalities. But they become obsolete with aging and the apparition of new techniques. Managing their evolution is a key issue in software engineering. This paper presents a strategy that has been developed at Broussais University Hospital in Paris to make a legacy system devoted to the management of health care units evolve towards a new up-to-date software. A two-phase evolution pathway is described. The first phase consists in separating the interface from the data storage and application control and in using a communication channel between the individualized components. The second phase proposes to use an object-oriented DBMS in place of the homegrown system. An application example for the management of hypertensive patients is described.

The HELIOS Medical Connection Services.

This paper presents the design and implementation of the HELIOS software component that deals with integration of medical applications in health information networks. The problem of interoperability between health information systems based on different data exchange syntaxes is first discussed. A meta-model, relying on CEN TC251 recommendations, is then presented as a possible solution to this problem and a message description language including these recommendations is proposed. Using this meta-model, the Medical Connection Services that comprises a generic message processing automaton, a resource manager and a mapper is able either to interpret messages expressed in a given syntax (e.g., EDIFACT, ASTM) and map them to the application objects or to automate the translation of the messages in another syntax. Special focus is given on the position of the Medical Connection Services within the HELIOS integration strategy (i.e., through data, presentation and communication). The problem of semantic heterogeneity is then discussed.

The HELIOS Unification Bus: a toolbox to develop client/server applications.

In the medical domain, new developments commonly rely on client/server architectures. But face to distributed environments, the software developers encounter a tremendously increasing complexity when building integrated applications. This paper presents the HELIOS Unification Bus (HUB), a communication integration framework for the HELIOS medical software engineering environment that allows the exchange of data between components that can be hosted on heterogeneous machines linked by a network. The HUB is developed as a C++ toolbox over UNIX and TCP/IP. It includes a message routing entity called router and a generic application programming interface (API), implemented as a C++ library, that allows to build easily software components compliant with the standardised HELIOS language. Messages conveyed by the bus are composite objects that are serialized to be transmitted over the bus using the ASN.1 ISO presentation protocol. The article describes the use of the bus to ease the development and execution of distributed medical applications and its role from the communication integration standpoint.

Using a meta-model to build a connection service in an object oriented medical application development environment.

Interoperability is a key issue in distributed health information systems. This paper presents the design and implementation of the Connection Service (CS) component of the HELIOS medical software engineering environment. An exchange message meta-model based on CEN TC251 recommendations and a message description language are proposed. Using this meta-model, the CS is able either to interpret messages expressed in a given syntax (e.g., EDIFACT, ASTM) and map them to the application objects or to automate the translation of the messages in another syntax. It is concluded that this meta-model approach contributes to the management of semantic heterogeneity.

A software engineering approach for medical workstations development.

Multimedia medical workstations represent the natural tool for accessing the hospital information system environment. They are complex medical systems that have to gather, in a single framework, a large collection of components dealing with multimedia medical objects. To remain current with both medical practice and with advances in the computer science field, they have to allow the iterative addition of new functions to the set of existing ones. In this paper, after a survey of commonly required medical workstation functional components, we shall try to discuss how a software engineering approach can streamline the development of a medical workstation. Different software engineering tools needed to build the functional components of a workstation are described. Their integration in a single dedicated environment is considered through four perspectives: data, presentation, communication and control. Benefits and limitations of an object-oriented approach are discussed.

An approach for the evaluation of software engineering environments in medicine.

This article examines several criteria for the evaluation of software engineering environments (SEE) in medicine. The study is restricted to the evaluation of the SEE itself, not of its by-products which are the medical applications developed with the SEE. Basic principles for an evaluation methodology are presented. They consist in determining the evaluation objectives and judging a SEE according to criteria which are grouped into three broad categories--functional, generic and environmental. Each category reflects a particular domain of evaluation of the SEE. Methods of measurement and questions highlighting these specific areas are mentioned. Criteria are extracted from the list of objectives that follows the HELIOS European AIM project of the Commission of the European Communities. Special emphasis is drawn on the criteria for which the medical specificity and usefulness of a SEE can be approach. For this purpose a method of measurement of such appropriateness is proposed.

Integrating management and expertise in a computerised system for hypertensive patients.

An expert system has been integrated to the data management system of the ARTEMIS programme for hypertensive patients. The patient database, which has been used since 1975, contains the medical records of about 20,000 patients. Information is interactively entered by physicians, nurses and secretaries on video display units. The computerised medical record has replaced the traditional handwritten medical record. The database management system is used to produce different summary reports (inpatient and outpatient care) and personalized recall letters which are mailed to the patients before their appointments. Suggestions provided by the expert system include additional information to be obtained (complementary patient interrogation, biological or radiological investigations, etc.), possible causes of hypertension, and medical prescriptions. The information base allows the description of both static knowledge (in the form of a semantic network) and dynamic knowledge (in the form of production rules). The inference system sequentially uses a combination of forward and backward chaining and performs both exact and approximate reasoning. The diagnostic performance of the expert system was evaluated in 100 cases of hypertension (50 of essential hypertension and 50 of secondary hypertension. Concordance between the diagnosis proposed by the expert system and the one proposed by the specialist was achieved in 92% of secondary hypertension cases and 88% of essential hypertension cases. It is suggested that the integration of data and knowledge management might enhance the overall acceptance by medical staff of a computerised system, and facilitate the validation of a knowledge base.