CDA is an XML-based, electronic standard used for clinical document exchange that was developed by Health Level Seven. CDA conforms to the HL7 V3 Implementation Technology Specification (ITS), is based on the HL7 Reference Information Model (RIM), and uses HL7 V3 data types. It was known earlier as the Patient Record Architecture (PRA).
is a flexible standard and is unique in that it can be read by the human eye or processed by a machine. This is due to its use of XML language, which also allows the standard to be broken into two different parts. A mandatory free-form portion enables human interpretation of the document, while an optional structured part enables electronic processing (like with an system). Text, images and even multimedia can be included in the document.
A CDA document could be, for example, any of the following: discharge summary, referral, clinical summary, history/physical examination, diagnostic report, prescription, or public health report. In short, any document that might have a signature is a viable document for CDA.
CDA does not specify a transport mechanism and can be utilized within a messaging environment or outside of it. Transport methods can include HL7 V2, HL7 V3, , MIME-encoded attachments, , or FTP. CDA is flexible enough to be compatible in a wide range of environments, and can be stored as a document in a computer system (permanently or temporarily) or can be transmitted as the content of a message.
In current practice, the Summary of Care Consolidated CDA is the document type primarily used in the United States due to the mandate required by Meaningful Use. Other examples of international implementations of CDA include: PICNIC (Ireland, Denmark, Crete), SCHIPHOX (Germany), MERIT-9 (Japan), Staffordshire (United Kingdom), and Regional Health Information System – Satakunta Macropilot (Finland).
CDA is an XML document that consists of a header and body. It is presented in this format:
CDA has three levels of document definition as defined by the organization, with Level One providing the least structure and Levels Two and Three providing greater structure: