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Health Information Exchange

Selected HIE Resources |  AHRQ-Funded Projects |  Background |  Areas of Current Investigation |

Selected HIE Resources

The following resources were selected from the Health IT Bibliography and represent peer-reviewed articles that describe best practices for the implementation and use of inpatient CPOE systems.

The Indiana Network for Patient Care: An Integrated Clinical Information System Informed by Over Thirty Years of Experience
Author(s): Biondich PG, Grannis SJ
Source: J Public Health Manag Pract (JPHMP) 2004 Nov;(Suppl):S81-S86. 2004 Nov;(NULL)(Suppl):S81-S86.
Summary: Presented in this article is the Indiana Network for Patient Care, an integrated citywide medical record system that promotes health quality by enabling efficient access to clinical information throughout the broader population of Indianapolis and the rest of the caregivers within the state of Indiana. It begins with a description of the system's infrastructure, which includes an explanation of how the system accomplishes data integration. This is followed by a series of descriptions and rationales behind the many clinical applications that interface with these data. The keys to success for this project include leveraging the value of the integrated data and identifying workflow inefficiencies, having a commitment to standards such as LOINC and SNOMED so all participants use the same standard language, and managing sociopolitical challenges specific to our community. In doing so, some of the factors that we feel contribute to the success of the system are illustrated.

The United Hospital Fund Meeting on Evaluating Health Information Exchange
Author(s): Hripcsak G, Kaushal R, Johnson KB, Ash JS, Bates DW, Block R, Frisse ME, Kern LM, Marchibroda J, Overhage JM, Wilcox AB
Source: J Biomed Inform 2007 Dec;40(6 Suppl):S3-S10 Epub 2007 Aug 30.
Summary: Health information exchange (HIE) projects are sweeping the nation, with hopes that they will lead to high quality, efficient care, but the literature on their measured benefits remains sparse. To the degree that the field adopts a common set of evaluation strategies, duplicate work can be reduced and meta-analysis will be easier. The United Hospital Fund sponsored a meeting to address HIE evaluation. HIE projects are diverse with many kinds of effects. Assessment of the operation of the HIE infrastructure and of usage should be done for all projects. The immediate business case must be demonstrated for the stakeholders. Rigorous evaluation of the effect on quality may only need to be done for a handful of projects, with simpler process studies elsewhere. Unintended consequences should be monitored. A comprehensive study of return on investment requires an assessment of all effects. Program evaluation across several projects may help set future policy.

A Randomized, Controlled Trial of Clinical Information Shared from Another Institution
Author(s): Overhage JM, Dexter PR, Perkins SM, Cordell WH, McGoff J, McGrath R, McDonald CJ
Source: Ann Emerg Med 2002 Jan;39(1):14-23.
Summary: Emergency physicians often must deliver medical care with minimal access to historical clinical information. A pilot randomized, controlled trial of providing information from a large, longitudinal, computer-based patient record system of clinical data from an urban hospital to emergency physicians at either of two urban EDs was conducted. The emergency physician received information both as a printed abstract and by means of online access to the computer-based patient record. We assessed charges, hospital admissions, repeat visits to EDs, and the emergency physicians' satisfaction with the information. This pilot study is the first to demonstrate the feasibility of sharing clinical information between different health care systems. We observed a trend toward cost savings at one of two hospitals and no differences in the quality measures we studied. Our experience underscores the difficulties inherent in studying the effects of community-wide health care interventions on cost and quality of ED care.

State and Community-based Efforts to Foster Interoperability
Author(s): Frisse ME
Source: Health Aff (Millwood--Spring Hope). 2005 Sep-Oct;24(5):1190-96.
Summary: The MidSouth eHealth Alliance is developing a comprehensive health information infrastructure supporting providers in three Tennessee counties. The greatest contribution of a formal RHIO might be to articulate and support a single, common legal and technical framework for realizing an interoperable regional health information infrastructure. The state will have to assume a greater role in setting and adopting guidelines for RHIOs; regions should continue their oversight of the technical infrastructure and enforcing regional policies. Success in the alliance's first year is the result of sustained leadership (and capital), a systematic assessment of regional needs and capabilities, a flexible technical architecture, and a critical review of best practices from four different data exchange models already operating in other states. Long-term evolution to a truly interoperable health information infrastructure will depend on the extent to which the alliance demonstrates value to consumers and practitioners.

Building an Interoperable Regional Health Information Network Today with IHE Integration Profiles
Author(s): Donnelly J, Mussi J, Parisot C, Russler D
Source: J Healthc Inf Manag (JHIM) 2006 Summer;20(3):29-38.
Summary: One of the key challenges of architecting electronic record sharing solutions that are scalable and can provide acceptable performance is how to create a longitudinal record for a patient when the desired data will be stored in several distributed point-of-service systems. This paper will review the design and standards selection process made byIntegrating the Healthcare Enterprise, a multinational collaborative of care providers and developers that analyzed a variety of approaches. Guidance will be offered to architects of regional health information organizations to take advantage of this experience and leverage the IHE Technical Framework, its testing processes, and tools to accelerate their projects and facilitate the interfacing of EHR systems serving different care settings from different vendors or developers. The implementation experience in 2005-2006 of the IHE Integration Profile specifications supporting an interoperable RHIO solution among various EHR systems from more than 30 vendors will be analyzed, with key lessons summarized.

The Santa Barbara County Care Data Exchange: What Happened?
Author(s): Miller RH, Miller BS
Source: Health Aff (Millwood--Spring Hope) 2007 Sep-Oct;26(5):w568-580 Epub 2007 Aug 1.
Summary: The Santa Barbara County Care Data Exchange was once one of the most ambitious and publicized U.S. health information exchange (HIE) efforts. Eight years after its inception, and several months after providing some data, the Santa Barbara Project shut down operations. Despite its developed HIE infrastructure, participants found no compelling value proposition in initial HIE services. Although there are several proximate causes for the project's slow progress - California HealthCare Foundation (CHCF) grant money, lack of community leadership, vendor limitations, and the duration of the process - the main underlying cause was lack of a compelling value proposition for Santa Barbara organizations. Even with fewer technology delays and more community leadership, other regional health information organizations (RHIOs) may also stumble over HIE service-value propositions without some combination of grants, incentives, and mandates that develop initial RHIO infrastructure and services and ensure provision of unprofitable yet socially valuable services.

The Indiana Network for Patient Care: a Working Local Health Information Infrastructure. An Example of a Working Infrastructure Collaboration that Links Data from Five Health Systems and Hundreds of Millions of Entries
Author(s): McDonald CJ, Overhage JM, Barnes M, Schadow G, Blevins L, Dexter PR, Mamlin B; INPC Management Committee
Source: Health Aff (Millwood--Spring Hope) 2005 Sep-Oct;24(5):1214-20.
Summary: The Indiana Network for Patient Care (INPC) is a local health information infrastructure (LHII) that includes information from the five major hospital systems (15 hospitals), the county and state public health departments, and Indiana Medicaid and RxHub. This network carries 660 million separate results. It provides cross-institutional access to physicians in emergency rooms and hospitals based on patient-physician proximity or on hospital credentialing. The network includes and delivers laboratory, radiology, dictation, and other documents to a majority of Indianapolis office practices. LHIIs must focus their limited resources on the high-volume data producers, which often are large hospital systems. LHIIs can be expected to improve efficiency and reduce cost growth. However, if their primary purpose becomes cost control, they will likely fail, as did the community health information networks (CHINs) of the 1990s. The INPC began operation seven years ago and is one of the first and best examples of an LHII.

AHRQ-Funded Projects

The Agency for Healthcare Research and Quality (AHRQ) has funded organizations across the country that are engaged in understanding the issues related to health information exchange. Selected projects include:

Title: Colorado Associated Community Health Information Exchange (CACHIE)
Principal Investigator: Arthur Davidson
State: CO

Title: Developing and Using Valid Clinical Quality Metrics for HIT with HIE
Principal Investigator: Rainu Kaushal
State: NY

Title: Electronic Prescribing and Electronic Transmission of Discharge Medication Lists
Principal Investigator: Rainu Kaushal
State: NY

Title: Improving Quality through Decision Support for Evidence-Based Pharmacotherapy
Principal Investigator: David Lobach
State: NC

Title: AHRQ Laboratory Exchange Meeting (PDF, 333 KB, Text Version


Health information exchange (HIE) refers to the sharing of clinical and administrative data across the boundaries of health care institutions, health data repositories, and States. Many stakeholder groups (payers, patients, providers, and others) realize that if such data are shared, health care processes would improve with respect to safety, quality, cost, and other indicators. However, sharing such data from a cultural and technical standpoint is not easy. Competing priorities, financial concerns, issues related to data ownership, and privacy and security are among someof the most difficult cultural barriers to overcome.


From a technological viewpoint, electronic health information systems are unable to share data (i.e., are not interoperable) because they represent data in different ways internally. In response to this problem, the information sciences community has developed standards (common ways of representing information) for health care data interchange. But many systems still do not adhere to these standards. Furthermore, many institutions still rely on paper-based systems and data are therefore not in an easily accessible (i.e., structured digital) format.

Building a clinical data sharing effort requires the translation of one data format into another. Data is typically shared in a common HL7 messaging format, but may contain different representations of the data within each message. The interface engine acts as a sort of "Rosetta Stone" for electronic messaging, ensuring that data from one system is translated appropriately for another system. For example, a lab system at a hospital may store its data using the LOINC coding standard, whereas a referral lab that performs work on behalf of the same hospital may store its data using a different coding format. If the hospital is to receive results electronically from its referral lab for storage in its central repository, the data from the referral lab must be translated to match the codes used by the hospital's lab system. This is the job of an interface engine, a piece of software that performs the following tasks:

  1. Translates data fromone of several formats into other supported formats.
  2. Links various systems within a clinical enterprise and sends data to those systems.
  3. Verifies the accuracy and conformance of messages to known standards for data communication. 

Interface engines receive incoming messages and route them to the appropriate information systems, and often the engine translates messages into formats that can be understood by the receiving system. Using an interface engine can simplify the integration of various data sources into existing health IT infrastructures. To route messages from one system to multiple disparate systems, the interface engine takes a single feed from the source system and then provides standardized output for other systems. This reduces the total number of interfaces needed between systems by effectively requiring a single interface from each system, regardless of the number of external systems that will use the messages.

  • Technically speaking then, HIEs must provide a number of important cultural and technical components:
  • Data-Sharing Agreements (define the polices and procedures for data sharing).
  • Data Pipes (the actual networks over which data will flow from place to place).
  • Interface Engines (systems that can interpret and translate incoming messages).
  • Data Models (the technical term for the architecture of the data sharing system).
  • Record Locator Service (one technical solution to finding the location of patient information).
  • Master Patient Index (MPI - a common medical record number or algorithm that identifies patients across several institutions).
  • Data Repository (the database that holds all of the patient data).
  • Standards (the coding and messaging schemes used to share data).
  • Interoperability (when two systems are able to talk to each other and share data they are said to be interoperable). 

Data sharing models also can vary from full aggregation type systems that collect all data centrally, normalize it (convert it to a common representation scheme), and store it to distributed models that host "record locator services," which serve as a "yellow pages" for where data reside and then fetch that data as needed.

Some thought leaders in HIE also are envisioning the notion of "data clearinghouses," whose role is to simply route data securely from one location to another without any effort at aggregation, normalization, or other data processing.


Implementation of these exchange efforts is intricate in terms of the breadth (how many data types are being shared and by what geographic areas) of the data sharing agreements, the types of data shared, and the value proposition for stakeholders. Not all HIEs share all data. For example, some HIEs are sharing exclusively specific types of nonclinical data:

  1. Eligibility determination (MassShare)
  2. Transitions in Care (Holomua Project)
  3. Public Health and Biosurveillance (CDC projects)
  4. Medication Histories (SureScripts, RxHub)
  5. Financial Transactions6.Visit Histories (Holomua Project)

Many others, such as the INPC, currently share clinical data as well.

Building small-scale efforts with concrete value propositions helps to lay the cultural and legal foundations in many settings with the hope of more extensive data sharing in the future.

More advanced HIEs such as the INPC are able to offer additional value-added services, including research data mining, clinical decision support, and quality reporting.

Areas of Current Investigation

More recent developments include the Nationwide Health Information Network (NHIN) initiative and the advent of Personal Health Records (PHRs). The NHIN is a secure backbone concept that links existing regional HIEs through a standard set of "core services" that allows one HIE to share data with another HIE. This effectively creates a "network of networks" that spans the Nation and provides stakeholders (payers, consumers, providers, policymakers, and administrators) with the ability to access data from across institutions, States, and repositories.

PHRs allow consumers to track their clinical data, medication histories and clinical notes and share them with other providers in an effort to reduce the fragmentation that exists in health care today. EMRs and HIEs can directly connect to (and send/receive data to/from) these PHRs.

Furthermore, many of the AHRQ health IT grantees and State and regional demonstration contactors are engaged in some sort of health information exchange. The lessons learned from these initiatives will help us better understand the issues and implement effective solutions.

The Health Information Technology Standards Panel (HITSP) is charged with the harmonization of standards that would allow for a common set of communication and coding standards. And the Certification Commission for Health Information Technology (CCHIT) has developed a certification process for EHRs that would allow them to interoperate with one another. Thus, purchasers will not need to buy all systems from one vendor, but rather, purchasers will be able to "mix and match" vendors as long as they are CCHIT compliant.

The information on this page is archived and provided for reference purposes only.