The document discusses building an e-health integration platform to facilitate interactions between social security organizations and heterogeneous health actors. It analyzes interoperability issues and how middleware and semantic technologies can help resolve them. Specifically, it proposes using an Enterprise Service Bus and semantic standards like OWL and RDF to build a service-oriented integration platform that supports data sharing and combined use of facilities across organizations. This would help provide value-added social security services by enabling automated interactions between technically diverse health and social security systems.
Towards an e health integration platform to support social security services
1. 6th International Policy and Research
Conference on Social Security
Emerging trends in times of instability:
New challenges and opportunities for social security
Luxembourg, 29.9–1.10.2010
Towards an e-health integration platform to support
social security services
Laura González, Guzmán Llambías, Pablo Pazos
Universidad de la República del Uruguay
Uruguay
3. Towards an e-health Integration Platform to Support
Social Security Services
Laura González, Guzmán Llambías, Pablo Pazos
Laboratorio de Integración de Sistemas, Instituto de Computación, Facultad de Ingeniería,
Universidad de la República del Uruguay. Julio Herrera y Reissig 565, CP 11300,
Montevideo, Uruguay.
{lauragon, gllambi}@fing.edu.uy, pablo.swp@gmail.com
Abstract
Nowadays, health services are increasingly related to social security systems. In many
countries, either health benefits are part of social security programmes or they are
associated to the rights of certain population (e.g. workers and their families). Such
relations generate interactions between the health and social security implementations,
especially when they are based on Information and Communication Technology (ICT)
systems.
The automation of these interactions presents various benefits like the possibility to
share and combine facilities and information, in order to provide value added social
security services. Various standards have been proposed to support these interactions
in an interoperable way, while leveraging the ICT assets within the interacting
organizations.
However, health actors usually adopt specific information representation standards (e.g.
HL7), which normally differs from the ones used by social security organizations.
Moreover, standards constantly evolve which present various challenges in terms of
flexibility, adaptability and interoperability.
This paper analyzes these issues and proposes solution approaches based on
middleware and semantic technologies. The paper focuses on interoperability issues
and how the facilities provided by advanced middleware and semantic technologies, like
Enterprise Service Bus and Semantic Web Services respectively, can assist in resolving
them. The solutions were analyzed, implemented and evaluated in the context of a
reference architecture based on service oriented principles. The work presented in this
paper constitute a starting point towards building an e-health integration platform, in
which social security organizations can leverage to interact with heterogeneous health
actors.
1. Introduction
Nowadays, there is a strong trend to coordinate the development of health insurance
programmes with social security programmes. This also involves the coordination of
welfare benefits with other social plans.
Additionally, health organizations are increasingly required to interact with each other, in
the context of various coordination initiatives that are being driven in many countries.
These coordination initiatives mainly seek to balance two strategies: expanding
universal coverage of risk and strengthening public health care provisions. [1]
In Uruguay, for example, a unified National Integrated Health System (Sistema Nacional
Integrado de Salud, SNIS) was implemented. This system constitutes a framework
through which public and private health organizations deliver health services to the
population. Broadly speaking, the SNIS aims at allowing the population to have health
services of the best possible quality, accessible in the most effective way and
4. implemented in the most rational way, trying to leverage the existing or future assets in
the involved organizations. [2]
One of the requirements to support these coordination initiatives is to have a fluent and
systematic integration among the ICT systems of the organizations. However, these
systems are usually very heterogeneous regarding technological platforms, capabilities,
terminologies and data models, among others, which prevent them from being
interoperable. Moreover, this heterogeneity can even occur in an intra-organizational
scheme.
The development of standards has been a key issue in achieving interoperability at
various levels. However, standards are not always adopted by health organizations, an
even if they are adopted, they present some issues which might cause difficulties to
achieve end-to-end interoperability [3]. Indeed, the “lack of commonly defined and
consistently implemented standards” has been identified as one of the main barriers
that prevent countries from achieving efficiency improvement through ICTs [4].
In this context, it is evident the need for an integration platform which addresses and
solves interoperability issues. This paper first describes concepts, technologies and
approaches regarding building interoperable information systems and analyzes some
examples of how they are being applied within the health domain. Additionally, it
proposes solution approaches, combining advanced middleware (i.e. Web Services and
Enterprise Services Bus) and semantic technologies, for building an e-health integration
platform which facilitates the integration of the involved organizations.
This work mainly originates from joint activities [6][7][8] with the Banco de Previsión
Social (BPS) [5], which is the main social security organization in Uruguay, and other
governmental Uruguayan organizations. The topics presented in this paper are being
addressed by the academic group Laboratorio de Integración de Sistemas (LInS) [9].
The remaining of this paper is organized as follows. Section 2 describes concepts,
technologies and approaches regarding building interoperable information systems and
provides examples of how they are being applied in the health domain. Section 3
proposes solution approaches, combining advanced middleware and semantic
technologies, to build a service-oriented e-health integration platform. Finally, section 4
presents conclusions and future work.
2. Interoperable Health Information Systems
This section presents various concepts, technologies and approaches for building
interoperable information systems and describes initiatives, products and tools which
leverage them in the health domain.
2.1 Interoperability
Achieving interoperability has become an essential requirement in almost every domain,
like the public and business sectors. Interoperability has been defined as the ability of
ICT systems, and of the business processes they support, to exchange data and to
enable the sharing of information and knowledge [10].
According to the European Interoperability Framework [10], interoperability can be
considered at three different dimensions: technical, semantic and organizational.
Technical Interoperability covers the technical issues of linking computer systems and
services. Semantic Interoperability is concerned with ensuring that the precise meaning
of exchanged information is understandable by any other application that was not
initially developed for this purpose. Organizational Interoperability is concerned with
defining business goals, modeling business processes and motivating the collaboration
5. of organizations that wish to exchange information and may have different internal
structures and processes.
The development of standards has been a key issue in achieving interoperability. For
example, Web Services [11] standards constitute nowadays the main mechanism to
achieve technical interoperability in a heterogeneous ICT environment. Moreover, the
Web Services-Interoperability (WS-I) [12] organization is an industry consortium that
seeks to enhance interoperability among Web Services implementations by publishing
implementation guidelines (e.g. WS-I Basic Profile 1.0) with the goal of enhancing
interoperability. Additionally, Semantic Web standards [13] provide mechanisms to
support semantic interoperability.
In the health domain, interoperability is also an essential issue. The Office of the
National Coordinator for Health Information Technology (ONC) [14] consider that
interoperable health IT can improve individual patient care in numerous ways like
providing complete, accurate and searchable health information, a more efficient and
convenient delivery of care, earlier diagnosis and characterization of diseases and
increased efficiencies in administrative tasks, among others. Additionally, the US
Federal Health Information Technology Strategic Plan states that “to effectively
exchange health information, health IT systems and products must use consistent,
specific data and technical standards” [15].
2.2 Health Standards
During the last decades, many health standards have been developed and are currently
being adopted by various health actors. For example, various international standards
have emerged to standardize the way clinical information is represented and structured.
The open standard OpenEHR [16] defines a generic reference model of clinical
information that is based on an ontological analysis of the healthcare domain. It only
represents the minimum most important semantic clinical concepts and its archetypes
constraint this model by defining specific clinical concepts. For example, the OpenEHR
reference model deals with generic clinical observations, but it does not include the
blood pressure, which is a particular observation.
As well, the Health Level Seven (HL7) [17] organization develops standards for
exchanging, managing and integrating health information. It also has a reference model,
but it is aimed to model the information to be exchanged among systems, unlike the
OpenEHR that models the internal architecture of medical record systems. HL7
information model contains clinical, demographic and accounting concepts, as it is an
emerging standard in the USA where the health system is closely linked to insurance
companies, so that accounting transactions were considered within the model. HL7
includes the CDA (Clinical Document Architecture), a standard that seeks to represent
any kind of electronic medical document for interchange.
Another standard of interest in the health domain is the CEN/ISO 13606, which is a
model for information exchange compatible with the OpenEHR model. Also, the ASTM
CCR (Continuity of Care Record) information model seeks to model medical summaries
to communicate them among different health services. OMG COAS (Clinical
Observation Access Service Model) provides an information model for communicating
clinical observations on a given patient. Finally, the International Healthcare Technology
Standards Developing Organization is rapidly promoting SNOMED CT as the preferred
terminology in healthcare.
2.3 Service Oriented Architecture
Service Oriented Architecture (SOA) is a logical way of designing a software system to
provide services in a network, via published and discoverable interfaces. SOA enables
6. interoperability and flexibility by converting monolithic and static systems into modular
and flexible components, represented as services, which can be requested via
technology standards. [18]
A SOA facilitates many of the tasks of developing enterprise applications, like their
integration, the development of business processes and leveraging legacy systems.
Additionally, a SOA provides the flexibility and agility that business users require,
allowing them to define coarse grained services which can be combined and reused to
address current and future business requirements. [18]
Healthcare organizations manage a large amount of software systems, which usually
need to integrate with each other, and must address evolving clinical requirements. As
well, organizations increasingly need to interact with other organizations. In this context,
SOA can provide healthcare organizations the mechanisms to support reuse and
sharing of system resources in an intra or inter-organizational scheme. [19]
There are currently many projects and initiatives in the health area which are taking this
direction.
In Denmark, for example, a service-oriented architecture based on Web Services was
built to support the online exchange of health care data among the various
heterogeneous IT systems in the health sector. The architecture forms a federation of
Web Services and enables secure and reliable authentication of end-users and
systems. As well, the architecture is based on national and international standards and
specifications. [20]
Additionally, the Healthcare Services Specification Project (HSSP) [21] is a collaborative
initiative, between HL7 and the Object Management Group (OMG), which sees the
need to specify services to support the information technologies in the health area. In
the context of this project, a practical guide to SOA in healthcare [22] has been
elaborated.
2.4 Web Services
A Web service is a software system identified by a URI, whose public interfaces and
bindings are defined and described using XML, and whose definition can be discovered
by other software systems. These software systems may then interact with the Web
Service in a manner prescribed by its definition and using XML based messages
conveyed by Internet protocols. [23]
The Web Service technology is based on three fundamental standards: Simple Object
Access Protocol (SOAP), Web Service Description Language (WSDL) and Universal
Description Discovery and Integration (UDDI). Additionally, many others standards,
know as WS-*, have emerged to address advanced requirements like security and
transactions, among others.
Web Services are the most common way to provide technical interoperability among
heterogeneous software systems. Additionally, given their characteristics, Web Services
are the preferred technology to implement services in a SOA. In healthcare, Web
Services are also being used to achieve these goals. Indeed, many efforts are being
made to provide guidelines in using health specific standards with Web Services
standards.
For example, the Web Services profile for HL7 (HL7WSP) [24] has the goal of providing
implementation best practices to promote the interoperability among applications which
exchange HL7 (version 3) messages, using Web Services. The profile considers
recommendations of other organizations, like the Web Services Interoperability (WS-I),
to leverage previous performed efforts to promote interoperability.
7. Additionally, Integrating the Health Enterprise (IHE) [25] is an initiative driven by
healthcare professionals and industry actors, with the goal of improving the way in
which computer systems in healthcare share information. To this end, a set of
guidelines have been elaborated to promote the coordinated use of established
standards such as DICOM and HL7, and their use with Web Services standards.
2.5 Enterprise Service Bus
An Enterprise Service Bus (ESB) is a standards-based integration platform that
combines messaging, Web Services, data transformation, and intelligent routing to
reliably connect and coordinate the interaction among heterogeneous applications. [26]
Even thought Web Services constitute a solid base to implement SOAs, their point-to-
point nature might affect maintainability and scalability of the solutions implemented with
this technology. In this context, the ESB provides a middle integration layer, with
reusable integration and communication logic, to enable the interaction between clients
and services in a SOA. The ESB accept requests in the form of messages, over which it
can perform different mediation operations (e.g. message transformation, validation and
enrichment), to solve heterogeneities between clients and services. The ESB promotes
loosely couple interactions between clients and services, and allows separating the
integration and communication logic from the business logic implemented by the
services.
Most ESBs provide capabilities to support transport protocol conversion, message
transformation, message routing and reliable messaging, among others.
ESBs can be leveraged in many ways to address interoperability issues and to
implement SOAs in healthcare organizations. Indeed, various ESB-like products are
incorporating health specific features.
Microsoft, for example, provides an Accelerator for HL7 [27] to extend Biztalk Server
capabilities by delivering a comprehensive HL7 messaging solution that enables sharing
of patient information within and between healthcare organizations. Additionally, Mirth
[28] is an open source healthcare messaging integration engine, which was built on top
of Mule (an open source Java ESB). Mirth allows message filtering, transformation and
routing, and provides an integration server that supports a variety of messaging
standards protocols for connecting to external systems, and numerous databases for
storing message data.
2.6 Metadata and Semantic Technologies
Metadata is structured information that describes, explains, locates, or otherwise makes
it easier to retrieve, use, or manage an information resource. Metadata is often called
data about data or information about information [29]. Describing resources with
metadata might facilitate interoperability.
Metadata schemes are sets of metadata elements designed for a specific purpose, such
as describing information resources of a specific domain. The definition or meaning of
the elements is known as the semantics of the scheme. [29]
Even though, there is not a unique language to express metadata in a digital way,
during the last years a set of standard specifications have been developed (e.g. XML,
RDF and OWL) in the context of the Semantic Web [31][32] Activity of the World Wide
Web Consortium (W3C). Figure 1 illustrates the stack of standards of the W3C, putting
on its bottom, the less semantic technologies and standards and on top, the most
expressive and rich ones.
8. Figure 1 - Semantic Web Standard Stack [34]
The eXtensible Markup Language (XML) constitutes a syntactic base for the rest of the
standards. The Resource Description Framework (RDF) is a data model based in triples
object-attribute-value. Additionally, formal ontology has recently emerged as a
knowledge representation infrastructure for the provision of shared semantics to
metadata [33]. An ontology is an explicit specification of a conceptualization, where a
conceptualization is an abstract, simplified view of the world that we wish to represent
for some purpose [30]. An ontology can be defined using the Web Ontology Language
(OWL).
In a Web Service context, OWL and RDF are two semantic standards too broad and
general to express the semantics of a Web Service. Therefore, standards like OWL-S
[35], WSDL-S [36] and WSMO [37] have emerged, expanding the possibilities to
achieve this challenge in a more specific and effective way. Web Services built using
Semantic Web technologies are commonly known in the literature as Semantic Web
Services and are becoming a very useful resource to address the semantic
interoperability problem.
In an e-health environment, the Artemis [38] and Miuras [39] projects are two examples
of the application of semantic technologies to solve this challenge.
The Artemis project addresses the interoperability problem during the exchange of
messages between client and Web Services that use different health standards. They
use the domain knowledge exposed by the existing healthcare informatics standards to
define a Service Functionality and a Service Message ontology. The Service
Functionality ontology is used to specify the operational meanings of Web services and
it is based on HL7. The Service Message ontology is used to specify the semantics of
Web service messages and is developed through electronic healthcare record based
standards such as ENV 13606 and GEHR [40].
On the other hand, the Miuras project is developing a semantic integration engine that
simplifies the exchange of information between health applications and health
information systems of a hospital. The engine simplifies the integration of
heterogeneous systems using the HL7 and ISO 13606 health standards.
3. Towards an e-health Integration Platform
This section presents solution approaches towards building an integration platform,
which leverages the facilities provided by middleware and semantic technologies to
address interoperability issues within an e-health domain.
9. The integration platform is proposed in the context of a SOA and integrates the
capabilities of ESBs, ontologies and Semantic Web Services.
3.1 General Description
The proposed solution [8] addresses the problem presented in Figure 2, where various
health organizations, that need to collaborate, support different version of standards to
interact with other organizations (e.g. HL7 v2 and v3). Moreover, some organizations
might not support any standard.
Figure 2 - Organizations supporting and not supporting standards
In this context, if an organization needs to interact with the rest of the organizations, it
has to know how to deal with the different standards or proprietary mechanisms they
manage. This might be a suitable solution when the number of organizations is small,
but as this number grows this solution becomes harder to implement and maintain.
Figure 3 presents an alternative solution which consists of an integration platform that,
leveraging enterprise service bus and semantic mechanisms, addresses these matters.
Within this platform, health organizations publish the services they provide to allow
other organizations to discover and consume them.
Figure 3 - e-health Integration Platform
10. The solution proposes using an Enterprise Service Bus (ESB) and extending it with
health specific capabilities. For example, the extended ESB incorporate components to
perform health standards related transformations. As well, it includes components to
invoke Semantic Web Services.
In order to consume the services published in the platform, clients send XML messages
to the extended ESB. This allows decoupling clients and services in terms of the
communication protocols and the health standards they used. It also provides location
transparency, that is, clients do not need to know the real location of the services in
order to consume them.
Additionally, the solution requires the definition of a global ontology, defined in OWL,
which includes the identified health domain concepts (e.g. Patient, Doctor, etc). Each
interacting organization has to map their communication data model to the concepts
defined within the global ontology. This might be performed by an expert user in charge
of administrating the platform.
Organizations have to publish their services, implemented as Web Services, in a
Semantic Web Services directory. These services have to be described using OWL-S
and the concepts within the global ontology. For example, an organization might specify
that a Web Service receives as an input parameter a Doctor and return as a response
the list of Patients associated with this Doctor. Both Patient and Doctor are concepts
defined in the global ontology.
When the ESB receives an XML request, it uses the defined mappings to transform this
input in an instance of the global ontology. This allows querying the Semantic Web
Services Directory in order to find a suitable service to fulfill the request, for example,
based on the specified input parameter. Once a service is found, it is invoked and the
response is transformed back to the communication format used by the client. In this
way, clients and services can interact without having to agree in the standards they use.
3.2 Implementation Details
The proposed solution was prototyped focusing in HL7 v2.x and HL7 v3 standards. The
prototype was built with JBoss ESB [41] which is the ESB product provided by JBoss.
Additionally, various technologies were used to assist in performing the required
transformation, discovery and invocation tasks. HAPI (HL7 Application Programming
Interface) [42], for example, is an open-source, object-oriented HL7 2.x parser for Java.
It was used to parse HL7 messages and be able to manipulate them as Java objects,
which simplifies this task. On the other side, Jena [43] is a Java framework for building
Semantic Web applications. It provides a programmatic environment for RDF, RDFS
and OWL, among others. Finally, OWL-S API [44] provides a Java API for
programmatic access to create, read, write, and execute OWL-S described atomic as
well as composite services.
4. Conclusions and Future Work
Throughout this paper, solution approaches to build an e-health integration platform
were analyzed. Concretely, various technologies for building interoperable information
systems were described, along with their application in an e-health domain. SOA, for
example, can provide healthcare organizations the mechanisms to support reuse and
sharing of system resources. ESBs allow decoupling clients and services at different
levels (e.g. communication protocol, supported health standards, etc). As well, semantic
technologies, in particular semantic Web Services, provide suitable mechanisms to
achieve semantic interoperability.
11. Based on this analysis, solution approaches were proposed in order to integrate
advanced middleware and semantic technologies in a consolidated platform.
Concretely, an integration platform, based on an ESB, a global ontology and semantic
Web Services, was specified and prototyped, as a first step towards building an e-health
integration platform. This platform allows publishing and consuming semantically
described e-health services, and leverages ESB capabilities to transform and route
requests and responses in order to resolve heterogeneities between clients and
services.
Despite of the fact that integrating semantic and ESB technologies in a consolidated
platform allows taking advantage of the capacities of both technologies, there are many
issues that still remain open. For example, although standards are a key element for
achieving interoperability, current standards present some problems which prevent
them from guaranteeing end-to-end interoperability [3]. Additionally, most middleware
technologies (e.g. ESBs) do not specifically address issues related with the health
domain. Therefore, an interesting work in this direction is to enrich current middleware
platforms to explicitly address and support health standards and solve domain specific
problems. Finally, given the mediation role of the ESB, it becomes a suitable place to
perform runtime adaptation tasks (e.g. replace service, use cache, etc) in order to
maintain the quality of service of the provided services.
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