Clinical Document Architecture

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Clinical Document Architecture
Year started1996 (1996)
First publishedNovember 2000 (2000-11)
Latest version2.0
OrganizationHealth Level Seven International
CommitteeStructured Documents Group
Base standards
Related standards
DomainElectronic health records
WebsiteCDA® Release 2

The HL7 Clinical Document Architecture (CDA) is an XML-based markup standard intended to specify the encoding, structure and semantics of clinical documents for exchange. In November 2000, HL7 published Release 1.0. The organization published Release 2.0 with its "2005 Normative Edition".[1]


CDA specifies the syntax and supplies a framework for specifying the full semantics of a clinical document, defined by six characteristics:[2]

  1. Persistence
  2. Stewardship
  3. Potential for authentication
  4. Context
  5. Wholeness
  6. Human readability

CDA can hold any kind of clinical information that would be included in a patient's medical record; examples include:[1]

An XML element in a CDA supports unstructured text, as well as links to composite documents encoded in pdf, docx, or rtf, as well as image formats like jpg and png.[3]

It was developed using the HL7 Development Framework (HDF) and it is based on the HL7 Reference Information Model (RIM) and the HL7 Version 3 Data Types.[citation needed]

The CDA specifies that the content of the document consists of a mandatory textual part (which ensures human interpretation of the document contents) and optional structured parts (for software processing). The structured part relies on coding systems (such as from SNOMED and LOINC) to represent concepts.[citation needed]

Consolidated Clinical Document Architecture[edit]

In 2012, in response to conflicting CDAs in use by the healthcare industry, the Office of the National Coordinator for Health Information Technology (ONC) streamlined commonly used templates to create the Consolidated-CDA (C-CDA).


The CDA standard doesn't specify how the documents should be transported. CDA documents can be transported using HL7 version 2 messages, HL7 version 3 messages, IHE protocols such as XDS, as well as by other mechanisms including: DICOM, MIME attachments to email, http or ftp.

Standard certification and adoption[edit]

The standard is certified by ANSI.[1]

CDA Release 2 has been adopted as an ISO standard, ISO/HL7 27932:2009.[4]

Country-specific implementations[edit]


Australia's Personally Controlled Electronic Health Record (PCEHR), known as "My Health Record", uses a specialized implementation of HL7 CDA Release 2.[5]

United Kingdom[edit]

In the UK the Interoperability Toolkit (ITK) utilises the "CDA R2 from HL7 V3 – for CDA profiles" for the Correspondence pack.[6][7]

United States[edit]

In the U.S. the CDA standard is probably best known as the basis for the Continuity of Care Document (CCD) specification, based on the data model as specified by ASTM's Continuity of Care Record. The U.S. Healthcare Information Technology Standards Panel has selected the CCD as one of its standards.[citation needed]

See also[edit]


  1. ^ a b c "FAQs". Health Level Seven International. Retrieved 10 August 2017.
  2. ^ "CDA® Release 2". Health Level Seven International. Retrieved 10 August 2017.
  3. ^ "HL7 Attachment Supplement Specification Release 2 Version 3.5".
  4. ^ "ISO/HL7 27932:2009 - Data Exchange Standards -- HL7 Clinical Document Architecture, Release 2".
  5. ^ "PCEHR Medicare Overview - CDA Implementation Guide v1.1". Australian Digital Health Agency. 27 September 2013. Archived from the original on 1 April 2018. Retrieved 10 August 2017.
  6. ^ "The Interoperability Toolkit". NHS Digital.
  7. ^ "ITK FAQs". Health and Social Care Information Centre. NHS CFH. Archived from the original on 17 May 2016. See 'What standards does ITK utilise?'

Further reading[edit]

External links[edit]