Categories of health data standards

Most health data standards can be grouped in four categories.

Information model standards Vocabulary / Terminology standards Content standards Communication standards

Information model standards specify how information that may be composed of many parts should be organised so that systems exchanging information with each other can reliably anticipate what structure to expect from another.

The architectural drawings for a building are probably a bit like information model standards. They specify where walls, doors and windows need to be, their sizes, and often what materials need to be used for each part. Although drawings may be used for many different kinds of building, architects tend to use standard conventions so that they can understand each other’s drawings, as can building contractors and other experts such as planning advisors. The drawing standards can be used for many different kinds of building, large and small, and the same is true for health information model standards.

In order for sender and receiver of information to communicate in an unambiguous manner, they have to agree on the terms to use to denote each particular concept. E.g. one clinician might rather use the word ‘breast cancer’ whereas the other might prefer ‘breast tumour’. And how to connect health information that was recorded in different languages?

This is where terminology standards come in. 

Terminology standards allow health information systems to communicate with each other by providing libraries of codes which identify each disease, allergy, medication or diagnosis through a unique code, and classification systems to represent health concepts.

Example

The terminology system SNOMED uses the code 254837009 for breast cancer. It is accompanied by a more detailed description ‘Malignant neoplasm of breast (disorder)’ and indicates that commonly used terms such as breast cancer or malignant tumour of breast are both referring to the same concept.

Each term is embedded in a hierarchical classification indicating relations with more general ‘parent’ terms and more specific ‘child’ terms. This would make it possible for a computer to find everybody in a hospital database who has had a hip replacement, even if the code used for the operation was “left hip operation” “or “right hip operation”.

Different standards will focus on different uses for different purposes, e.g. ICD-10 focuses on diseases and diagnoses, mainly for statistics and invoicing. SNOMED focuses on clinical terminology for recording, aggregating and sharing clinical data.

Content standards make sure that both sender and receiver who exchange electronic messages or documents, understand how the content is structured and/or what datasets they contain.

Examples

ISO has developed a content standard for Electronic prescriptions. More and more health professionals are prescribing medication through a digital technology in order to provide a dispenser (e.g. a pharmacist) with the accurate information to deliver the right medication to the right patient, including all relevant information with regard to its correct and safe use. The different ePrescibing technologies in use around the globe highlighted the need for an international standard describing the minimally required information to accompany the ePrescription in order to have exactly the required medicine dispensed to the patient.

The content standard HL7 (Health Level Seven International) provides a series of templates that are relevant for specific situations, e.g.:

– The Discharge Summary Template provides disparate hospital systems a standard format to report back to a primary care provider or other parties interested in the patient’s hospital care.

– The Continuity of Care Template provides a “snapshot in time,” constraining a summary of the pertinent clinical, demographic, and administrative data for a specific patient and allows physicians to send electronic medical information to other providers without loss of meaning.

Health information is usually exchanged between computer systems through a telecommunications network, hence it has to be converted into a format that can be transmitted this way.

Communication standards specify how information should flow between systems, rather than how each system should organise its information internally.

These communication standards sometimes make use of some of the above standards, such as information model, terminology and content standards because these other standards define the information that has to be transmitted by the communication standards.

Example

FHIR is a communication standard published by HL7 to facilitate the exchange of health care information between organisations. The standards can be used to transmit electronic health record information between two hospitals, or to exchange information between a patient and their general practitioner, for example.