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Selected Resources |  Background |  Areas of Current Investigation

Selected Resources

The following resources were selected from the Health IT Bibliography and represent peer-reviewed articles that describe best practices for the development and use of health IT standards.

LOINC, a Universal Standard for Identifying Laboratory Observations: a 5-year Update
Author(s): McDonald CJ, Huff SM, Suico JG, Hill G, Leavelle D, Aller R, Forrey A, Mercer K, DeMoor G, Hook J, Williams W, Case J, Maloney P
Source: Clin Chem 2003 Apr;49(4):624-33.
Summary: The Logical Observation Identifier Names and Codes (LOINC) database provides a universal code system for reporting laboratory and other clinical observations. Its purpose is to identify observations in electronic messages such as Health Level Seven (HL7) observation messages, so that when hospitals, health maintenance organizations, pharmaceutical manufacturers, researchers, and public health departments receive such messages from multiple sources, they can automatically file the results in the right slots of their medical records, research, and/or public health systems. For each observation, the database includes a code (of which 25,000 are laboratory test observations), a long formal name, a "short" 30-character name, and synonyms. LOINC codes are being used by large reference laboratories and federal agencies, and are part of the Health Insurance Portability and Accountability Act (HIPAA) attachment proposal. Laboratories should include LOINC codes in their outbound HL7 messages so that clinical and research clients can easily integrate these results into their clinical and research repositories.

The HL7 Clinical Document Architecture
Author(s): Dolin RH, Alschuler L, Beebe C, Biron PV, Boyer SL, Essin D, Kimber E, Lincoln T, Mattison JE
Source: J Am Medl Inform Assoc (JAMIA). 2001 Nov-Dec;8(6):552-69.
Summary: Health Level 7 (HL7) is developing standards for the representation of clinical documents (such as discharge summaries and progress notes). These document standards make up the HL7 Clinical Document Architecture (CDA). This article presents the approach and objectives of the CDA, along with a technical overview of the standard. The CDA is a document markup standard that specifies the structure and semantics of clinical documents and can include text, images, sounds, and other multimedia content. The first release of the standard has attempted to fill an important gap by addressing common and largely narrative clinical notes. Being a part of the emerging HL7 version 3 family of standards, the CDA derives its semantic content from the shared HL7 Reference Information Model and is implemented in Extensible Markup Language (XML). The HL7 mission is to develop standards that enable semantic interoperability across all platforms; the CDA is helping to move us closer to the realization of this vision.

The Continuity of Care Record
Author(s): Kibbe DC, Phillips RL Jr, Green LA
Source: Am Fam Physician 2004 Oct 1;70(7):1220, 1222-23.
Summary: For more than a decade there has been agreement in the United States that information technology is a critical part of any effort to achieve high performance health care for everyone. The potential benefits of moving from sequences of disconnected and episodic visits between patients and doctors to continuous connectivity are widely recognized to be of great value to patients, families, communities, investigators, payers and purchasers, employees, health organizations, and physicians. The Continuity of Care Record (CCR) is a document being developed to foster and improve continuity of patient care, reduce medical errors, increase patients' role in managing their health, enable epidemic monitoring and public health research, and ensure at least a minimum standard of secure health information transportability. This article discusses the various ways that physicians and patients are able to use this personal health information standard tool.

The Unified Medical Language System: An Informatics Research Collaboration
Author(s): Humphreys BL, Lindberg DAB, Schoolman HM, Barnett GO
Source: J Am Medl Inform Assoc (JAMIA). 1998 Jan-Feb;5(1):1-11.
Summary: In 1986, the National Library of Medicine (NLM) assembled a large multidisciplinary, multisite team to work on the Unified Medical Language System (UMLS), a collaborative research project aimed at reducing fundamental barriers to the application of computers to medicine. The UMLS illustrates the strengths and challenges of substantive collaboration among widely distributed research groups. Over the past decade, advances in computing and communications have minimized the technical difficulties associated with UMLS collaboration and also facilitated the development, dissemination, and use of the UMLS Knowledge Sources. Wider use of the World Wide Web has increased the visibility of the information access problems caused by the multiple vocabularies and many information sources that are the focus of UMLS work. The time is propitious for building on UMLS accomplishments and making more progress on the informatics research issues first highlighted by the UMLS project more than 10 years ago.


The process of transmitting health information between systems is often referred to as clinical messaging or health data exchange. When multiple information systems can seamlessly exchange messages, they are said to be interoperable.

Standards enable interoperability by encoding health information using a common, generally agreed upon "language" that multiple systems can read. As an analogy, think about constructing a railway from Boston to Indianapolis. The construction crews in Indiana, Ohio, Pennsylvania, and Massachusetts must lay tracks using the same standard so that the train is not derailed during its journey because the tracks in Ohio are narrower than those in Pennsylvania. Similarly, standards in health information technology ensure that test results stored in a laboratory information system can be automatically transmitted from the lab to the patient's electronic health record (EHR) at the hospital or physician office.

There are two main concepts to consider about standards:  syntax and semantics. Syntax refers to the grammar rules for a defined "language" so that the electronic messages being exchanged can be properly deconstructed when received. Semantics ensuresthat message components are coded so that their meaning can be interpreted or understood (e.g., which lab tests were performed and what their values are) when the message is deconstructed.

Widely Adopted Syntaxes

Widely Adopted Semantics

Standards are created, adopted, and revised through consensus-based processes managed by standards development organizations (SDOs). The SDOs are composed of members that use the standards, typically organizations such as hospitals, laboratories, and pharmacies. Proposed changes are balloted and members comment on, then vote on, the changes. SDOs are typically accredited by organizations such as the American National Standards Institute (ANSI) or the International Standards Organization (ISO). Oversight of SDOs provides confidence, ensures transparency, and promotes coordination (harmonization).

Adoption of health IT standards has grown steadily over the years in part from support of Federal Government Agencies and Institutes like the Agency for Healthcare Research and Quality (AHRQ), the National Library of Medicine (NLM), and the Food and Drug Administration (FDA).

  • AHRQ has facilitated the use and development of standards through its sponsorship of research and national research conferences and its collaborations with other federal agencies. In one study, AHRQ and NLM examined the existing vocabulary coverage of clinical concepts (Three Decades of Research on Computer Applications in Health Care).
  • NLM has developed the Unified Medical Language System (UMLS) with a Metathesaurus that integrates concepts and terms from a large number of health-related vocabularies and classification systems.
  • The FDA maintains the National Drug Code (NDC) Directory, the universal set of all drugs manufactured, prepared, propagated, compounded, or processed for commercial distribution in the United States. 

Organizations adopting health information technologies should consider solutions or applications based on standards. Standards will make current and future interface with other systems easier, deployed locally or at other organizations (e.g., payers, pharmacies). When selecting a solution or application it is important to consider standards and how the solution uses standards. Products certified by the Certification Commission for Health IT (CCHIT) require use of standards recognized by the Federal Government. This provides a good starting point for identifying solutions that, at minimum, support the use of standards when interfacing with other systems.

Areas of Current Investigation

Health information exchange, defined as exchanging health care information across organizational and regional boundaries, is an area of health IT that depends on standards. In 2005, the U.S. Department of Health and Human Services (HHS) announced the creation of the Health Information Technology Standards Panel (HITSP). This public-private collaborative produces recommendations and reports on standards designed to support health information exchange, including the development of a Nationwide Health Information Network (NHIN). Detailed specifications, reports, and recommendations developed by HITSP are available for public review and comment and participation is open to all interested parties. Once HITSP-recommended standards are approved, they become part of recognized certification processes.

Electronic prescribing (e-prescribing) functionality also depends on standards. AHRQ has taken a lead role in studying e-prescribing standards, providing funding and leadership for the following projects:

  • AHRQ and the Centers for Medicare & Medicaid Services (CMS) jointly administered a pilot project to test initial standards for electronic prescribing (e-prescribing). This project, carried out by five pilot sites across the Nation, resulted in a report that summarized the findings across the pilot projects. The report provides direction for the Federal Government on standards adoption and disseminates key data on e-prescribing outcomes.
  • Research funded by AHRQ at Indiana University has revealed that the HL7/FDA Structured Product Label (SPL) can be used as a primary source for drug information in e-prescribing systems. The study found that SPL labels currently contain only a fraction of RxNorm clinical drugs, but they account for three-quarters of community pharmacy dispensing records. 
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