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IHE: an implementation framework based on messaging standards.

Copyright Ringholm bv © 2003,2012. All Rights Reserved.
See http://www.ringholm.com/docs/00830_en.htm for the latest version of this document.
Author: Ren´┐Ż Spronk - Sr.Consultant, Ringholm bv
Document status: Final, version 1.6 (2012-10-02)
Please send questions and comments to Rene.Spronk@Ringholm.com.


The IHE (Integrating the Health Enterprise) initiative offers implementation profiles for transactions used to communicate clinical data within the healthcare enterprise. These implementation profiles are created by a consensus process among professionals; the profiles are based on existing messaging standards such as HL7 and DICOM. Conformance to IHE profiles is tested by means of testing tools and a live system-to-system testing event called the Connectathon. A European connectathon took place in 2012 in Berne, Switzerland.

IHE is known for its implementation profiles related to imaging (Radiology); its scope is however continuously expanding into other areas. This paper contains a high-level overview of the IHE framework and some of the results of the most recent European Connectathon. It is assumed that the reader is familiar with the concept of systems integration based on the exchange of messages. Detailed knowledge of any specific messaging standard will not be assumed.

Validating a DICOM related test.   Something seems out of whack.
The Barcelona (2006) Connectathon (Images courtesy of IHE-Europe)

1. Introduction

While information systems are essential to the modern healthcare enterprise, they cannot deliver full benefits if they operate using proprietary protocols or incompatible standards. Decision makers need to encourage comprehensive integration among the full array of information systems. The goal of the IHE (Integrating the Health Enterprise) initiative is to stimulate integration of healthcare information resources. [IHE-MS]

IHE offers a commonsense approach to this goal. Using established standards and working with direction from medical and information technology professionals, industry leaders in healthcare information systems are cooperating under IHE to agree upon implementation profiles for the transactions used to communicate clinical data within the enterprise. Their incentive for participation is the opportunity to demonstrate that their systems can operate efficiently in standards-based, multi-vendor environments with the functionality of real hospital information systems. Moreover, IHE enables vendors to direct product development resources toward building increased functionality, rather than redundant interfaces. [IHE-MS]

IHE was originally started in the US by the HIMSS and RSNA organizations. It has gained strong support internationally over the last few years. In Europe, IHE has been organized under the sponsorship of the European Association of Radiology (EAR) and the medical imaging industry, through its trade association, COCIR. National professional associations have sponsored IHE demonstrations in various European countries. Most of the active members of IHE-Europe can be found in France, Germany, Italy and the U.K.

The initial implementation profiles were limited to those required for Radiology, or imaging in general. The IHE initiative is however not limited to any specific area. Various groups have extending IHE by other domains. For example, laboratory implementation profiles have been created by a group of national IHE organizations (notably Japan and France). The implementation profiles are tested during a yearly gathering where vendors of healthcare information systems systematically test their compliance. These tests are known as a connectathon. The next section describes the aims and details of implementation profiles and the connectathons.

Ongoing discussion during the connectathon.  
Participants in the Padova (2004) Connectathon (Images courtesy of IHE-Europe)

2. The IHE technical Framework

IHE involves an intensive, ongoing process of collaboration and communication among key parties. Experienced healthcare professionals identify priorities for integration. Industry representatives achieve consensus on a specific implementation of standards-based transactions to meet each identified clinical need. They record these decisions in the IHE Technical Framework, a detailed, freely available integration resource. Participating companies build into their systems the capability to support IHE transactions. Rigorous testing--performed with software tools developed by IHE and during a live system-to-system testing event called the Connectathon--ensures a high degree of conformity with the Technical Framework. Finally, public demonstrations at major meetings of healthcare professionals provide the incentive for companies to participate, as well as a forum to educate users and purchasers about integration and visible proof of the effectiveness of in annual cycles, expanding in scope incremental to address an ever-broader range of clinical needs. [IHE-FAQ]

Lab order workflow (LSWF).
Figure 1. Laboratory order Scheduled Workflow (LSWF)

The IHE implementation profiles are based on a description of workflow processes in the form of use-cases, actors (or: application roles), transactions and workflow diagrams. A draft of the workflow diagram for the laboratory order workflow is shown in figure 1. After the definition of the workflow appropriate standard-based transactions have to be found that cover the scope of clinical data that has to be exchanged between the actors. Transactions are exchanges of information between actors using messages based on established standards. For example, the transactions of the laboratory order workflow will in all likelihood be based on the HL7 and ASTM messaging standards. Each transaction is defined with reference to a specific standard and by means of additional detailed information, including use cases. This is done to add greater specificity and ensure a high level of interoperability between systems. The integration profiles are documented in the IHE Technical Framework, a detailed document which defines the integration capabilities of IHE-conformant systems.

The localization of implementation profiles, and the choice of messaging standards which shall be used is left up to the national IHE organizations. They may decide to follow the guidance of IHE or IHE-Europe, or to create implementation profiles specifically targeted at their local needs.

Success!   Technical managers validating a test.
The European Connectathon (Images courtesy of IHE-Europe)

3. Connectathon

The IHE Technical Framework describes the details of the various integration profiles. Companies that claim compliance with one or more integration profiles configure their systems to support IHE transactions. Rigorous testing is performed with the aid of a set of software tools (known as the MESA tools) and during a live system-to-system testing event called the Connectathon. This testing ensures a high degree of conformity with the Technical Framework.

An overview of the room where the 2006 connectathon was held.
The Barcelona (2006) Connectathon(Images courtesy of IHE-Europe)

As an example of the typical characteristics of a connecthon: during the 2012 European connectathon the 300 participants from 18 countries, representing 83 different vendors, tested 94 systems within a period of 4.5 days. Over 3000 tests were performed. Each test was comprised of between 3 and 10 individual steps, each of which had to be validated by one of the independent IHE Technical Managers. Of the 3000 tests, about 2900 tests were verified and approved.

The testing and validation process is supported by a web-based application. This application can be used by participants to sign up for specific tests, as a reference during the execution of the individual steps in each test, and as a record of the testing and validation status of the tests.

4. Summary

The IHE framework defines workflow processes and transactions in a way which greatly aids the process of achieving interoperability between systems. Vendors describe and publish the intented conformance of their product with the IHE Technical Framework in the form of a 'IHE Integration Statement' (in HL7-terms: a conformance profile). The connectathon testing events are a very effective mechanism for vendors to ensure the compliance of the participating system.

By choosing the most applicable existing messaging standards it is ensured that the data is encapsulated in a message according to a well defined standard in a particular area. We're confident that vendors and governmental organizations in various European countries will recognize the pragmatic concepts behind the IHE framework and embrace it to ensure interoperability of systems.

Well, you see DICOM defined it a different way...   Validating a test.
The Barcelona (2006) Connectathon (Images courtesy of IHE-Europe)

5. Acknowledgements

We would like to thank Eric Poiseau (Univ. Rennes), Karima Bourquard (GMSIH) and Nick Brown (MIMIC) for their suggestions and comments regarding this whitepaper. We also thank IHE-Europe for their permission to publish the images from the Aachen connectathon. The paragraphs marked [IHE-MS] and [IHE-FAQ] are slightly edited versions of materials taken from the RSNA website. The image of the Laboratory Scheduled Workflow is © IHE-Europe.

6. References

[IHE-FAQ] "IHE Frequently Asked Questions", http://www.ihe.net/
[IHE-MS] "IHE Mission Statement", http://www.ihe.net/

About Ringholm bv

Ringholm bv is a group of European experts in the field of messaging standards and systems integration in healthcare IT. We provide the industry's most advanced training courses and consulting on healthcare information exchange standards.
See http://www.ringholm.com or call +31 33 7 630 636 for additional information.