Modelling the epidemiology of Escherichia coli ST131 and the impact of interventions on the community and healthcare centres.

ST131 Escherichia coli is an emergent clonal group that has achieved successful worldwide spread through a combination of virulence and antimicrobial resistance. Our aim was to develop a mathematical model, based on current knowledge of the epidemiology of ESBL-producing and non-ESBL-producing ST131 E. coli, to provide a framework enabling a better understanding of its spread within the community, in hospitals and long-term care facilities, and the potential impact of specific interventions on the rates of infection. A model belonging to the SEIS (Susceptible-Exposed-Infected-Susceptible) class of compartmental models, with specific modifications, was developed. Quantification of the model is based on the law of mass preservation, which helps determine the relationships between flows of individuals and different compartments. Quantification is deterministic or probabilistic depending on subpopulation size. The assumptions for the model are based on several developed epidemiological studies. Based on the assumptions of the model, an intervention capable of sustaining a 25% reduction in person-to-person transmission shows a significant reduction in the rate of infections caused by ST131; the impact is higher for non-ESBL-producing ST131 isolates than for ESBL producers. On the other hand, an isolated intervention reducing exposure to antimicrobial agents has much more limited impact on the rate of ST131 infection. Our results suggest that interventions achieving a continuous reduction in the transmission of ST131 in households, nursing homes and hospitals offer the best chance of reducing the burden of the infections caused by these isolates.

Introducing guideline management in the healthcare information system architecture.

This paper analyses different benefits of the full integration of components for clinical guideline management in the information system architecture of a healthcare organization. Subsequently, we propose a methodology for the development of these components based on the European prEN12967 standard, in order to facilitate this integration. Benefits are studied from several viewpoints. First, from the healthcare professional user viewpoint, as a powerful decision support tool, by which the Electronic Health Record of a specific patient could suggest the appropriate guidelines to apply and a particular assistance plan for him or her. We are centered in co-morbidity patients because these tasks are especially difficult to accomplish in this kind of patients. Second, from the guideline creation viewpoint, we analyze how the tacit knowledge implicit in the healthcare information system could be the base for the explicit representation of knowledge in a guideline and the posterior validation of these guidelines. Our approach is in agreement with today's new paradigm for evidence-based medicine demanded by healthcare professionals. The proposed method for guideline management components development is compliant with CEN's prEN12967 European standard, and consequently follows ITU-T's ODP methodology.

Demographic management in a federated healthcare environment.

OBJECTIVE: The purpose of this paper is to provide a further step toward the decentralization of identification and demographic information about persons by solving issues related to the integration of demographic agents in a federated healthcare environment. The aim is to identify a particular person in every system of a federation and to obtain a unified view of his/her demographic information stored in different locations. METHOD: This work is based on semantic models and techniques, and pursues the reconciliation of several current standardization works including ITU-T's Open Distributed Processing, CEN's prEN 12967, OpenEHR's dual and reference models, CEN's General Purpose Information Components and CORBAmed's PID service. RESULTS: We propose a new paradigm for the management of person identification and demographic data, based on the development of an open architecture of specialized distributed components together with the incorporation of techniques for the efficient management of domain ontologies, in order to have a federated demographic service. This new service enhances previous correlation solutions sharing ideas with different standards and domains like semantic techniques and database systems. The federation philosophy enforces us to devise solutions to the semantic, functional and instance incompatibilities in our approach. CONCLUSION: Although this work is based on several models and standards, we have improved them by combining their contributions and developing a federated architecture that does not require the centralization of demographic information. The solution is thus a good approach to face integration problems and the applied methodology can be easily extended to other tasks involved in the healthcare organization.

A standard ontology for the semantic integration of components in healthcare organizations.

In this paper we introduce an ontology that covers all the terminology involved in the ODP standard. This ontology has been extended with concepts taken from the prEN12967 in order to apply it in the healthcare domain. Describing components formally and using this ontology, their semantic integration can be eased together with the benefits derived from the assistance to the automatic discovery, selection, invocation and composition of components facilities.

Standardization of demographic service for a federated healthcare environment.

The main objective of this paper is to contribute into the process of the standardization of a demographic service in a federated healthcare environment. Our approach is based on semantic web techniques and aimed at the reconciliation of several previous standardization works.

Empowering citizens with access control mechanisms to their personal health resources.

BACKGROUND: Advancements in information and communication technologies have allowed the development of new approaches to the management and use of healthcare resources. Nowadays it is possible to address complex issues such as meaningful access to distributed data or communication and understanding among heterogeneous systems. As a consequence, the discussion focuses on the administration of the whole set of resources providing knowledge about a single subject of care (SoC). New trends make the SoC administrator and responsible for all these elements (related to his/her demographic data, health, well-being, social conditions, etc.) and s/he is granted the ability of controlling access to them by third parties. The subject of care exchanges his/her passive role without any decision capacity for an active one allowing to control who accesses what. PURPOSE: We study the necessary access control infrastructure to support this approach and develop mechanisms based on semantic tools to assist the subject of care with the specification of access control policies. This infrastructure is a building block of a wider scenario, the Person-Oriented Virtual Organization (POVO), aiming at integrating all the resources related to each citizen's health-related data. The POVO covers the wide range and heterogeneity of available healthcare resources (e.g., information sources, monitoring devices, or software simulation tools) and grants each SoC the access control to them. METHODS: Several methodological issues are crucial for the design of the targeted infrastructure. The distributed system concept and focus are reviewed from the service oriented architecture (SOA) perspective. The main frameworks for the formalization of distributed system architectures (Reference Model-Open Distributed Processing, RM-ODP; and Model Driven Architecture, MDA) are introduced, as well as how the use of the Unified Modelling Language (UML) is standardized. The specification of access control policies and decision making mechanisms are essential keys for this approach and they are accomplished by using semantic technologies (i.e., ontologies, rule languages, and inference engines). RESULTS: The results are mainly focused on the security and access control of the proposed scenario. An ontology has been designed and developed for the POVO covering the terminology of the scenario and easing the automation of administration tasks. Over that ontology, an access control mechanism based on rule languages allows specifying access control policies, and an inference engine performs the decision making process automatically. The usability of solutions to ease administration tasks to the SoC is improved by the Me-As-An-Admin (M3A) application. This guides the SoC through the specification of personal access control policies to his/her distributed resources by using semantic technologies (e.g., metamodeling, model-to-text transformations, etc.). All results are developed as services and included in an architecture in accordance with standards and principles of openness and interoperability. CONCLUSIONS: Current technology can bring health, social and well-being care actually centered on citizens, and granting each person the management of his/her health information. However, the application of technology without adopting methodologies or normalized guidelines will reduce the interoperability of solutions developed, failing in the development of advanced services and improved scenarios for health delivery. Standards and reference architectures can be cornerstones for future-proof and powerful developments. Finally, not only technology must follow citizen-centric approaches, but also the gaps needing legislative efforts that support these new paradigms of healthcare delivery must be identified and addressed.

Modeling the healthcare assistance process for comorbidity patients compliant with prEN12967.

The increment of life expectancy in our society, and the consequent population ageing, anticipate that the health sector must face the challenges associated with a growing population group of elderly patients with numerous disorders, generally chronic. In this work we introduce a framework to support the communication and information management tasks involved in a coordinated care of this kind of patients. This framework has been developed in the European context, it is compliant with CEN's prEN12967, and follows ITU-T's ODP methodology, that facilitates its integration in any system following this standard.

Analysis of burn injury by digital simulation.

A non-linear mathematical model for digital simulation of fluid distribution in burn patients during the first 48 h after injury is presented. The technique employed in the model construction is the system dynamic approach. A five-compartment model has been considered. The control mechanisms incorporated are adequate for describing the interactions between plasma and interstitial fluid and between the extra- and intracellular compartments. With the model we are able to analyse the dynamic behaviour of many variables, for example the plasma, interstitial, extra- and intracellular fluid volumes and the plasma and interstitial proteins in burn and non-burn areas. These values are very difficult to measure in daily clinical practice, although they indicate the actual state of a burn patient. The simulation results are compared with measured values in a series of patients from a burn unit in a general hospital.

[A new proposal on the neural component of the control system of renal blood flow. Analysis using digital simulation]. / Nueva propuesta del componente neural del sistema de control del flujo sanguíneo renal. Análisis por simulación digital.

A mathematical, non-lineal model for digital simulation of the neural control of blood renal flow (BRF) has been built, by using the system dynamic techniques. The control mechanisms considered have been the BRF regulation by means of a renal intrinsic system, and by means of an RNA-dependent system, being the latter a product of the peripheral sympathetic activity, of a tonic inhibitory system with a central origin, and of a system that inhibits this last one, which has an intrarenal origin. For the validation of the model, a spinal section has been simulated, and the data have been compared with the reported in the bibliography. The use of this model permits an approach to the study of different variables in physiological or pathological circumstances in man, especially of those involved in the neural regulation of the BFR, obviating the technical and ethical obstacles of experimental techniques and leading to the design of new animal trials.

Preliminary evaluation of a full-time falling monitor for the elderly.

The article presents the early outcomes of the evaluation of an intelligent accelerometer unit (IAU) utilized for detecting the falling events of elderly people . The overall design of the monitor where the IAU is integrated is briefly exposed. The outcomes of a laboratory study carried out over 8 volunteers show that the device is able to distinguish true falling events from normal activities like fast walking or going up/downstairs. The influences of the subject and the environment have been taken into account profiting from the processing capacity of the monitor distributed architecture.