Interoperability is the capacity for “two or more systems or components to exchange information and to use the information that has been exchanged.” (Institute of Electrical and Electronics Engineers 1990)
But given the technical, social, political, and organizational factors that revolve interoperability, the term means difference things to different people. The HIMSS Dictionary of Healthcare Information Technology Terms, Acronyms and Organizations lists 17 different definitions to encapsulate these different perspectives. The HL7 EHR Interoperability Work Group attempts to define interoperability through a 3-prong framework:
- Technical Interoperability – The exchange of data between different systems, where the meaning of the content is irrelevant to the act of communication between the systems.
- Semantic Interoperability - The exchange of information where meaning of the data is understood and interpreted uniformly between all systems. Standardized codes and identifiers are utilized by all systems, making data syntax digestible and parsing possible.
- Process Interoperability - The coordination of business processes between stakeholders so systems interoperate symbiotically. Work processes need to revolve around electronic systems, and systems need to be used in day-to-day business operation, and as intended for this interoperability to be effective.
Standards and Controlled Vocabularies
Standards are the essential shared languages that systems need in order to converse with one another. Standards are often composed of controlled vocabulary schemas that codify predefined and authorized terms so data is easily identifiable and retrievable. The Unified Medical Language System (UMLS) provides a number of standards are relevant to the interoperability of health information systems.
General Markup Languages
XML XML (eXtensible Markup Language) is text format open standard very popular in web-based applications. First drafted in 1998, XML is popular for its level of flexibility and easy human readability.
RDF: RDF (Resource Description Framework) is a metadata data model based on the XML standard. RDF schema are structured into 3 constructs: Classes, Properties, and Utility Properties. These constructs allow metadata to be stored, providing a depth of detail that make semantic activity possible.
A Sample of Standards Relevant to Biomedical Informatics
HL7: Health Level 7 is a not-for-profit organization dedicated to the development of healthcare informatics interoperability standards. HL7 is currently in version 3 and include the standards: Reference information Mode (RIM) (ISO/HL7 21731), HL7 Development Framework ( ISO/HL7 27931), V3 Messaging, and V3 Clinical Document Architecture (ISO 10781). See HL7
SNOMED CT: Systematized Nomenclature of Medicine – Clinical Terms is based on SNOWMED, the first multi-axial coding system in healthcare to be developed. SNOMED CT is a critical controlled vocabulary used to store and retrieve clinical care records detailing over a million medical concepts to detail patient information.
UMLS: The U.S. National Library of Medicine’s Unified Medical Language System (UMLS) is a set of controlled vocabularies aimed at expanding computer system abilities to parse biomedical information. The UMLS is composed of 3 applications: the Metathesaurus, the Semantic Network, and the SPECIALIST Lexicon. Between these applications, the UMLS seeks to automatically read, parse, and share data between systems using controlled vocabularies and natural language processing.
ICD: The International Classification of Diseases (ICD) is the classification used to code all general epidemiological, many health management purposes and clinical use. ICD-9 Clinical Modification (ICD-9-CM) is the current standard for diagnoses billing.
DICOM: DICOM (Digital Imaging and Communications in Medicine) is a standard for storing and retrieving medical imaging.
LOINC: Logical Observation Identifiers Names and Codes (LOINC) is ontology for classifying medical laboratory observations and results.
 Benson, Tim. Principles of Health Interoperability HL7 and SNOMED. Dordrecht: Springer, 2010.
 HIMSS Dictionary of Healthcare Information Technology Terms, Acronyms, and Organizations. Chicago, IL: HIMSS, 2010.
 Hersh, William R. Information Retrieval a Health and Biomedical Perspective. New York, NY: Springer, 2009
Submitted by Brian Sandoval