Deborah Kohn, MPH, RHIA, CHE, CPHIMS
Actors, Domains, Electronic Health Records, Implementation Guides, Integration
Profiles, Interface, Interoperability, Longitudinal Health Records, Portability, Protocols,
Standards Development Organizations, Technical Frameworks, Transactions
Health professionals across the continuum of care agree that an effective and appropriate sharing of information between machines, systems, and even stakeholders, known as "interoperability," is perhaps, the most important enabler for improving the quality, cost, and efficiency of care delivery. For decades, however, the ability to share data between different software systems, residing on different hardware, from different software and hardware vendors, has eluded healthcare information technology (IT) professionals.
Integrating the Healthcare Enterprise (IHE) is a multinational healthcare initiative that develops and publishes domain -based (for example, radiology, laboratory, etc.) Technical Frameworks (that is, implementation guides ) that consist of internationally accepted and vendor-neutral implementations of existing healthcare IT data standards , including but not limited to Health Level 7 (HL7) and Digital Imaging and Communications in Medicine (DICOM). Technical Frameworks allow the established standards to be implemented in a uniform fashion --therefore, allowing the seamless passing of vital health information from application to application, system to system, and setting to setting within and across the entire healthcare enterprise. As such, worldwide healthcare organizations (HCOs) that have implemented healthcare information systems by following the IHE guidelines have achieved effective systems integration and facilitated appropriate sharing of medical information within and across their enterprises. As a result, they saved time and money as well as supported optimal patient care.1
The DICOM standard was jointly developed and first published in 1985 by the American College of Radiology (ACR), representing radiologists, and the National Electrical Manufacturers Association (NEMA), representing manufacturers of diagnostic imaging equipment, such as computed tomography (CT) scanners and magnetic resonance (MR) equipment. DICOM introduced an information model for the management of diagnostic image data in radiology. Initially, the DICOM standard specified the hardware connection (that is, interface) for transferring unstructured image data in and out of the imaging equipment. Soon thereafter, it specified a set of rules (that is, protocols) for the network operation of the interface for reliable and quick image data transfer. Without the standard, each device required a custom-developed interface. This was expensive for HCOs to develop and maintain.
During the late 1980s to the mid-1990s, an array of "DICOM-compliant" digital radiographic systems from different vendors became more commonplace in HCOs. In addition, Picture Archiving and Communications Systems (PACS) started to be implemented in radiology to electronically capture, transmit, store, and display the diagnostic images, requiring interfaces to/from other information systems in the organization. Much to the dismay of HCOs, the organizations soon realized that the interoperability of DICOM was limited to specific point-to-point interfaces and required a higher coordination between information systems when the number of information systems was greater than two. Consequently, despite DICOM compliance, HCOs could not achieve interoperability in radiology and, in most cases, had to develop many custom interfaces.
In 1987, the consensus-based HL7 standard was developed by the Health Level Seven standards development organization (SDO). The HL7 standard specified working interfaces for a wide range of clinical and administrative structured data messages (for example, patient registration, order entry, and observation reporting), allowing disparate healthcare applications to exchange data. However, HL7 lacked an information model for the management of coded data. Consequently, great flexibility of the standard led most healthcare information system developers to interpret and implement the HL7 standard in a conflicting, non-uniform, and proprietary manner. Despite HL7 compliance, HCOs had little or no interoperability, thwarting efforts for reliable, quick, and cost-effective automation of business processes.
In 1998, to face this growing standards dilemma and help decrease the costs of implementations in the area of multiple vendor systems integration, IHE was formally launched by the Healthcare Information Management Systems Society (HIMSS) and the Radiological Society of North America (RSNA). Focusing on the existing DICOM and HL7 standards, IHE developed the first versions of the IHE Radiology Technical Framework to clearly define how to use DICOM and HL7 to resolve common information system communication tasks that span multiple information systems in radiology. IHE worked to bridge both blatant and subtle gaps between the two standards in radiology. For example, one standard allowed 28 characters in an order form field, while the other standard allowed only 25 characters. Also, IHE worked to simplify transactions in the two standards in radiology to ensure that information has integrity all the way through the framework. For example, when a trauma case requires performing a radiology procedure before identifying a patient, how does that unidentified patient information later get reconciled with the patient's record?
The first demonstration of the IHE Radiology Technical Framework was at the RSNA Annual Meeting in 1999 and the annual HIMSS Conference and Exhibition in 2000. Since then, the Radiology Technical Framework has been updated and expanded annually, after a period of public review, and maintained regularly by the IHE Technical Committees through the identification and correction of errata.
Today, IHE includes SDOs, such as ACR-NEMA and HL7; professional societies, such as HIMSS, RSNA, the American College of Cardiology (ACC), and the American College of Clinical Engineering (ACCE); medical specialists, other care providers, and related industry professionals; IT professionals; and, approximately 80 (and growing), image modality, medical device, and healthcare information system vendors from Europe, Asia, and North America. These IHE stakeholders voluntarily agree to participate in the guideline development process and collaborate to improve the way systems in healthcare share critical information. For example, the medical specialists, clinicians, and related healthcare and IT professionals define the Technical Frameworks' needs. The IT professionals and vendors embed the Technical Frameworks' guidelines into their systems / products. The professional societies supervise the documentation, testing, promotional requirements, and demonstrations.
In addition, today, IHE has developed and published Technical Frameworks for Laboratory and the IT Infrastructure. IHE has developed and will soon publish the Technical Framework for Cardiology. IHE is expanding into other clinical domain areas, including clinical engineering and pharmacy / medication management, hoping to develop and publish their Technical Frameworks in the near future. As such, IHE is collaborating with other professional societies as sponsors (for example, the ACC and ACCE), medical specialists, and IT professionals and vendors to accomplish this.
IHE supports the use of cross-industry standards, such as those developed by the Internet Engineering Task Force (IETF). In addition, IHE is looking to work with other SDOs. For example, IHE is planning to work with the Institute of Electrical and Electronics Engineers (IEEE) to provide implementation guides for the SDO's existing Medical Information Bus (MIB P1073) for communication between bedside instruments and other medical devices and healthcare information systems. Also, IHE plans to support implementations of the American Society for Testing and Materials (ASTM) for ASTM's Healthcare Informatics Committee 31's consensus-based Continuity of Care Record (CCR) standards. CCR defines a minimum set of patient data to ensure continuity of care when patients move between disparate care settings.
IHE Around the World
IHE North America consists of the US (and its current sponsors HIMSS, RSNA, ACC, ACCE) and Canada, whose Canada Health Infoway and Canadian Association of Radiology sponsors have supported IHE.
Rapid international growth of IHE primarily has been led by activities in Europe, where IHE is organized under the sponsorship of the European Association of Radiology and the medical imaging industry through its trade association, COCIR. The European initiative was first sponsored and demonstrated in France with the Groupement pour la Modernisation des Systemes d'Information des Hospitaliers and the French Radiology Society. Other initiatives were subsequently demonstrated in Germany and Italy. Today, national committees in these countries along with those in the United Kingdom and Scandinavia operate under the umbrella of IHE Europe.
IHE Asia held its first demonstration in 2002 in Japan, sponsored by the Japanese Radiological Society and the Japanese Association for Hospital Information Systems. This demonstration showed not only integration of radiology information systems and modalities, but it included access to laboratory results. Other countries participating in IHE Asia are South Korea and Taiwan.
IHE Europe and IHE Asia coordinate closely with IHE North America.
IHE Technical Frameworks
IHE Technical Frameworks consist of common vocabularies for humans to use to unambiguously discuss how to integrate heterogeneous information systems. Also, they consist of the common, standards-based vocabularies for systems to use in exchanging medical information.
IHE Technical Frameworks are process-oriented. The Technical Frameworks refer to each process (or problem / solution scenario or specific set of capabilities of integrated systems) as an "Integration Profile." IHE Integration Profiles organize the processes to address specific patient care needs and to conveniently reference the functionality described in the Technical Frameworks. For example, version 5.5 of the IHE Radiology Technical Framework has the following 12 Integration Profiles:
- Basic Security
- Consistent Presentation of Images
- Key Image Notes
- Evidence Documents
- Simple Image and Numeric Report
- Access to Radiology Information
- Scheduled Workflow
- Presentation of Grouped Procedures
- Post-Processing Workflow
- Reporting Workflow
- Charge Posting
- Patient Information Reconciliation
Version 1.0 of the IHE IT Infrastructure Technical Framework has the following five Integration Profiles, which were demonstrated at the joint HL7-IHE Interoperability Demonstration at the 2004 Annual HIMSS Conference and Exhibition:
- Retrieve Information for Display
- Enterprise User Authentication
- Patient Identifier Cross-Referencing
- Patient Synchronized Applications
- Consistent Time
IHE Technical Frameworks identify the products (or information systems or components of information systems) that produce, manage or "act" on information associated with the operational process (or Integration Profile) in the enterprise. The Technical Frameworks refer to these products as "actors." For example, for radiology, the imaging modality as the Image Acquirer, the radiology information system as the Order Filler, or the healthcare information system as the Order Placer are some of the actors in a list of more than 20.
Also, the Technical Frameworks stipulate the data standards-based interactions involved in the process and required to integrate the information flow between the information systems to accomplish a particular task. These standards-based interactions are called "transactions." In other words, transactions are interactions or exchanges of information between actors. For each transaction, specific standards are used to transfer the required information through a message. Because IHE specifies in detail the terms of the transactions, nothing is left for further interpretation! The Radiology Technical Framework has identified almost 50 transactions, such as Patient Registration, Procedure Scheduled, Storage Commitment, and Retrieve Images.
Other IHE Benefits and Deliverables
IHE Technical Frameworks help HCOs determine the need to upgrade existing products to implement the required standards-based transactions. Also, they help to specify the transactions when HCOs consider healthcare information systems and products for purchase, such as in Requests for Proposals (RFPs). For example, HCOs can incorporate the following, sample verbiage into their RFPs:
- The product shall meet the requirements of the IHE ___ Technical Framework.
- The product shall implement the following IHE actors ...
- The required actors (above) shall support the following IHE Integration Profiles...
- Acceptance testing parameters shall be based on the (above) IHE Integration Profiles.
- Which IHE Integration Profiles does your product support on which systems?
- The Radiology Information System shall meet the following requirements:
- Integration Profile: Scheduled Workflow
- Actors: Order Filler and Performed Procedure Step Manager
- Required Transactions: 1, 2, 3, 4, 5, 6, 7, 11, 12, 20, and 21
Since IHE is a customer-driven initiative, IHE publishes Product Evaluation Worksheets that provide convenient tools for evaluating the IHE capabilities of the domain-based products. Each IHE Integration Profile is listed, followed by the actors required to fully implement it.
In addition, IHE issues Integration Statements to vendors. Such statements validate those Technical Framework Integration Profiles and Actors that have been successfully implemented in vendors' products. IHE does not certify products.
Also, IHE supports public demonstrations and related educational activities to promote the deployment and maintain the Technical Frameworks by HCOs and healthcare IT vendors. IHE supports rigorous cross-vendor testing to ensure a high degree of conformity with the Technical Frameworks. The centerpiece of the testing deliverable is called the Connect-a-thon, an annual, weeklong, interoperability-testing event featured in North America, Europe, and Asia. During this event, participating companies exchange information with complementary systems from multiple vendors by performing all of the transactions required for the "actor" roles that the companies have selected in support of the defined Integration Profiles in a Technical Framework. The Connect-a-thon offers vendors the unique opportunity to remove barriers to integration that otherwise would have to be determined at the customer's site and expense. Vendors have responded overwhelmingly that the Connect-a-thons address key issues in company product development plans.
IHE and Electronic Health Record Systems
After over a decade of "talk," there has been a great deal of recent "movement" within both the public and private sectors in encouraging all healthcare providers to migrate from paper- and film-based health records to systems that electronically store and manage health information. In part, this movement is due to a growing recognition that (1) complete patient information (paper- and film-based and / or electronic) is not always available; and, (2) a stronger IT infrastructure, either within the enterprise and / or between enterprises, is integral to providing complete electronic information, directly addressing such global concerns as the need to improve the safety and quality of healthcare, constantly-rising healthcare costs, and matters of national and international security related to the health sector.
Significant progress is well under way as IHE works to speed the rate and quality of systems interoperability within HCOs to improve the efficiency and effectiveness of clinical practice. Using existing industry standards, IHE Technical Frameworks allow for the required information sharing, providing complete, integrated electronic patient information for care providers as well as patients--and for the acceptance among the companies that build the electronic systems on which the care providers and patients rely. Because of IHE, today, available electronic information systems that communicate freely across different vendor platforms include but are not limited to patient registration / admission / discharge / transfer systems, diagnostic imaging systems, order communication systems, PACS, radiology and laboratory information systems, reporting systems, and patient scheduling systems. Each system contributes pieces of patient information that, when integrated, make up the "complete" electronic health record system (EHR-S).
For the next two years, the US will be moving forward with the Draft Standard for Trial Use on the EHR-S Functional Model and Standard. Currently, this draft standard provides a national reference model that outlines key direct and supportive care EHR-S functions for the private sector. In addition, it outlines key infrastructure EHR-S functions for the private sector. While IHE does not claim to master or address the definition and all aspects of a complete and interoperable EHR-S, IHE with the national draft standard will be bringing the realization of complete patient information and stronger IT infrastructure closer.
But the realization of the EHR-S does not begin or end there. For example, other initiatives are in process to create a nationally accepted, common data set of patient information that can be electronically passed from one clinician to the next when a patient transfers to a different caregiver or is referred to a new healthcare setting. Agreeing to and identifying the common data set as well as the method of transmission are key considerations for another standards dilemma known as portability . Portability supports the realization of patients' longitudinal health records (that is, pre-natal to post-mortem), in a lifetime consisting of dozens of patient encounters with dozens of diverse providers and provider organizations.
IHE has begun to get involved in meeting some of the functional requirements of portable EHR-Ss, such as being document-centric and document content-generic and requiring the distributed exchange of information across encounters, cross-enterprise. For example, IHE has proposed that its IT Infrastructure Technical Framework separate the EHR into two, distinct concepts: an EHR-LR (Longitudinal Record), for communicating health information across care episodes and among providers, and the evolving EHR-CR (Care Record) for specific clinical care information within provider organizations. Such a Technical Framework leverages existing healthcare IT data standards, such as HL7's Clinical Document Architecture (CDA) and ASTM's CCR. Also, it leverages a developing Integration Profile: EHR-Cross-Enterprise Clinical Document Sharing (XDS), which complements both CDA and CCR. As such, this proposal might spearhead the creation of IHE "Clinical Affinity" domains (for example, local health information infrastructures [LHIIs], specialty networks, etc.) where clinical documents, not data, are shared.
In summary, with IHE continuing to collaborate with well-established standards bodies and other EHR-related initiatives worldwide, providers can be sure that their needs for EHR-S interoperability and portability will be met more cost-effectively and rapidly, and vendors can focus on executing solutions to achieve them.
- Brookwood Medical Center, a 586-bed acute care facility in Homewood, AL reported annual cost savings of $1M due to implementing "IHE-sharpened electronic technologies." Hatfield, Scott. "IHE is Big Business." Advance for Health Information Executives (November 2003): 18.
|Source: 2004 IFHRO Congress & AHIMA Convention Proceedings, October 2004|