Information Centre

SNOMED CT (Systematized Nomenclature of Medicine: Clinical Terms) is the leading coded medical terminology database used by information systems, managed by SNOMED International. SNOMED CT consists of more than 350,000 concepts that are logically connected to one another. Every concept has a linguistic and a semantic description. You can access the international and local content of SNOMED CT via a public browser.

Estonia is a member country of SNOMED and TEHIK is SNOMED's Estonian contact point and the administrator of the Estonian edition.

As Estonia is the member country, using SNOMED CT in Estonia is free of charge. However, for getting the free licence, you have to sign up here.

As an Estonian resident, you can take the trainings offered by SNOMED International free of charge or with a discount (make sure that the corresponding discount percentage is invoiced after logging in). To get started, we recommend choosing the free entry course: SNOMED CT Foundation Course.

The most common way to use SNOMED CT in information systems is through the extension files available to the registered user. In addition, SNOMED International offers a Snowstorm terminology service and plenty of free software and tutorials to make using SNOMED as easy as possible.

If you have questions, please contact us at: [email protected].

Founded in 1987, Health Level Seven International (HL7) is a not-for-profit, ANSI-accredited standards developing organisation dedicated to providing a comprehensive framework and related standards for electronic health information. The name " Health Level-7" refers to the seventh level of the International Organisation for Standardisation (ISO) seven-layer communications model for Open Systems Interconnection (OSI) – the application level.

The community of HL7 is organised as a world-wide organisation and country-based affiliate organisations. The headquarters is in Michigan, and there are members in more than 50 countries.

HL7 V3, HL7 CDA and HL7 FHIR are international standards created by HL7 International, used in the data exchange of health data. The purpose of the standard is to define the structure and semantics of the amount of information used in data exchange so that it would be as reproducible, unambiguous and reusable as possible.

CDA® R2 – Clinical Document Architecture Release 2

This is a data exchange standard for documents based on XML, the goal of which is to specify the structure and semantics of clinical documents. In Estonia, the HL7 CDA standard is used as the basic standard for data exchange in the medical records health information system. CDA R2 was recognised as a standard by ANSI in 2005. It is a document-based data exchange, where data is exchanged via the so-called ready-made documents.

CDA documents acquired their machine-readability via HL7 Reference Information Model (RIM).

CDA R2 guarantees the following characteristics in a CDA document: safety of the presented information, information management, support for authentication requirements, maintaining context and wholeness, human readability, usability of a binary file (e.g., PDF, multimedia components, photos, etc). These characteristics make CDA very flexible for using in different environments. Although CDA is considered an extremely complex standard among medical system developers, it has become one of the most successful standards developed by HL7.

V3 – Version 3

An XML-based messaging standard (interaction message) that supports healthcare data exchange.

HL7 v3 messages are based on XML syntax. V3 introduced the use of "documents" as an alternative architecture for exchanging health data. The HL7 V3 uses a model-based object-oriented methodology and includes specifications for message and non-message standards. V3 increases quality and reduces variability in HL7 standards, thus meeting the more complex and diverse needs of its members.

HL7 v3 messages are based on XML syntax. V3 introduced the use of "documents" as an alternative architecture for exchanging health data. The HL7 V3 uses a model-based object-oriented methodology and includes specifications for message and non-message standards. V3 increases quality and reduces variability in HL7 standards, thus meeting the more complex and diverse needs of its members.

HL7 FHIR® R4 – Fast Healthcare Interoperability Resources

An interoperability standard designed to facilitate the exchange of health data on a data/event basis. Facilitates the transfer of health information to health service providers and individuals on a variety of devices from computers to tablets and phones. It also allows third-party developers to provide medical applications that can be easily integrated into existing systems. HL7 FHIR® R4 is based on previous HL7 standards such as V2, V3, but it is easier to implement, as it uses modern web-based API technology. Including HTTP-based RESTful protocol and a choice for transferring data (e.g., JSON, XML, RDF). FHIR offers an alternative to document-based approach. For example, key elements of healthcare, such as patients, appointments, epicrises, and medications, can be manipulated through the URLs of these resources.

An upTIS project to upgrade the health information system is underway at TEHIK, and one of its components is the transfer of data exchange to the HL7 FHIR standard. FHIR offers a so-called data-based data exchange, where a message is composed of many interconnected FHIR resources. FHIR messages can also be sent and requested separately, which is a much more flexible approach compared to CDA.

Under the leadership of TEHIK, the FHIR community has also been established, which unites FHIR stakeholders from TEHIK, other state agencies, health service providers and IT companies. If you would like to join the FHIR community or get more information, please contact us at: [email protected].