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).
Clinical Document Architecture (CDA) HL7 CDA uses XML for encoding of the documents and breaks down the document in generic, unnamed, and non-templated sections. Documents can include discharge summaries, progress notes, history and physical reports,... 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 Electronic Medical Record (EMR), as defined in Defining Key Health Information Technology Terms (The National Alliance for Health Information Technology, April 28, 2008): An electronic record of health-related information on an individual that can be... 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.
Implementation of 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 , Digital Imaging and Communications in Medicine (DICOM) is a common format for image storage. It allows for handling, storing, printing, and transmitting information in medical imaging. Visit DICOM website. Synonyms: Digital Imaging and Communications..., MIME-encoded attachments, HTTP (Hypertext Transfer Protocol) is the foundation for application-level communication on the internet., 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 Electronic Health Record (EHR), as defined in Defining Key Health Information Technology Terms (The National Alliance for Health Information Technology, April 28, 2008): An electronic record of health-related information on an individual that conform... (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:
- Header – includes patient information, author, creation date, document type, provider, etc.
- Body – includes clinical details, diagnosis, medications, follow-up, etc. Presented as free text in one or multiple sections, and may optionally also include coded entries.
CDA has three levels of document definition as defined by the HL7 is a Standards Developing Organization accredited by the American National Standards Institute (ANSI) to author consensus-based standards representing a board view from healthcare system stakeholders. HL7 has compiled a collection of message form... organization, with Level One providing the least structure and Levels Two and Three providing greater structure:
- Level One – the root hierarchy, and the most unconstrained version of the document. Level One supports full CDA semantics, and has limited coding ability for the contents. An example of a level one constraint on document type would be a “Discharge Summary” with only textual instructions.
- Level Two – additional constraints on the document via templates at the “Section” (free text) level. An example of a level two constraint would be a “Discharge Summary” with a section coded as Medications.
- Level Three – additional constraints on the document at the “Entry” (encoded content) level, and optional additional constraints at the “Section” level. An example of a level three constraint would be a “Discharge Summary” with a section coded as Medications with coded RxNORM entries for each medication.
- Health Standards In The News: CCD and Consolidated CDA  (blog post)
- Untangling Consolidated CDA in Meaningful Use