CDA R2 Extensions

Purpose

This page documents extensions to CDA R2 which have been created for use in CDA Release 2.0 Implementation Guides.

SDTC Extensions

The namespace for all Structured Documents Workgroup extensions in urn:hl7-org:sdtc. This namespace was used because at the time these extensions were created, the name of the Structured Documents Work Group was the Structured Documents Technical Committee. Approval of an extension to appear in the urn:hl7-org:sdtc namespace by the Structured Documents workgroup does not give the extension any status other than being eligible to appear in this list and that namespace. Some extensions have been published in Normative or Informative documents, and so have standing as being part of standard, DSTU or HL7 informative specification in the context of that specification.

Extensions created by the Structured Documents workgroup follow certain rules established during the creation of the HL7 CCD Implementation guide.

An extension is a collection of element or attribute declarations and rules for their application to the CDA Release 2.0.

• The namespace for extensions created by the HL7 Structured Documents Working Group (formerly Structured Documents Technical Committee) shall be urn:hl7-org:sdtc. Note: Some implementation guides have incorrectly reported the namespace as urn:hl7-org:stdc.
• All extensions are optional. An extension may be used, but need not be.
• Extension element names shall be derived from attributes defined in the RIM.
• Each extension element shall use the same HL7 vocabularies and data types as used by CDA Release 2.0.
• Each extension element shall use the same conventions for order and naming as is used by the current HL7 tooling.
• An extension element shall appear in the XML where the expected RIM element of the same name would have appeared had that element not been otherwise constrained from appearing in the CDA XML schema.

The following extensions have been approved by the HL7 Structured Documents Workgroup. The specification first defining the extension appear in bold. NOTE: While specifications defining the extension may come from organizations other that the HL7 Structured Documents Working Group, they were discussed with, and "approved" by the working group as being eligible to appear in the stdc namespace.

Extension	Definition	Defined/Used by
sdtc:asPatientRelationship	Each participant other than an informant may have zero or more relationship roles with the patient. Each of these roles can be expressed by an asPatientRelationship element which further describes the type of role in a code element. The informant participant already supports specification of the relationship between the informant and the patient via the RelatedEntity class, and therefore should not include this extension.(CCD)	CCD
sdtc:birthTime	The <sdtc:birthTime> element allows for the birth date of any person to be recorded. The purpose of this extension is to allow the recording of the subscriber or member of a health plan in cases where the health plan eligibility system has different information on file than the provider does for the patient.	CCDA HITSP C32 QRDA
sdtc:deceasedInd	The deceasedIndextension (= “true” or “false”) in the family history organizer on the related subject is used inside to indicate if a family member is deceased.	CCD CCDA HITSP C32 QRDA
sdtc:deceasedTime	The deceasedTime extension in the family history organizer on the related subject allows for reporting the date and time a family member died.	CCD CCDA HITSP C32 QRDA
stdc:desc	The desc extension allows multimedia depictions of patients, healthcare providers, or other individuals to be included in a CDA document. It may be used in any person (or derived) entity, and appears after the entity name.	N/A
sdtc:dischargeDispositionCode	The sdtc:dischargeDispositionCode element allows the provider to record a discharge disposition in an encounter activity.	CCDA HITSP C32 QRDA
sdtc:id	CDA Release 2.0 does not provide a mechanism to determine when two participants in different roles are in fact the same entity (i.e., an entity can be a person, organization or device). A CDA Document identifies each participant through the application of a role identifier. This identifier can be used to trace the participation of an entity in a given role, but cannot necessarily be used to determine that two entities are the same. While more role identities could be provided whose intended use is to unify the entities, this is better modeled through the use of an entity identifier. Therefore, to facilitate this capability, this guide defines an extension to CDA Release 2.0 that allows the person or organization playing the role to be uniquely identified, by the inclusion of an identifier on the entity. (CCD) The id extension in the family history organizer on the related subject allows for unique identification of the family member(s). (CCDA)	CCD CCDA HITSP C32 QRDA
sdtc:patient	The sdtc:patient extension element allows for the patient identifier used by a given provider to be reported. The provider in their role as an assigned entity is related to the patient.	HITSP C32 IHE PCC TF
sdtc:raceCode	The raceCode extension allows for multiple races to be reported for a patient.	CCDA HITSP C32 QRDA
sdtc:valueSet	The valueSet extension attribute allows the implementer to reference a particular value set from which a code was drawn. This extension represents a preadoption of the HL7 R2 Datatypes valueSet attribute	QRDA
sdtc:valueSetVersion	The valueSetVersion extension attribute allows the implementer to reference a specific version of a value set. This extension represents a preadoption of the HL7 R2 Datatypes valueSetVerson attribute	QRDA

A W3C Schema representing these extensions, and incorporating them in the correct locations in the HL7 CDA Release 2 Schema can be found in the [QRDA Release 2 Draft Standard for Trial Use]

Other HL7 Extensions

The following extensions have been approved by other HL7 Working Groups or Affiliates for use in CDA Release 2.0 Implementation Guides.

Non-HL7 Extensions

The following extensions have been created and/or approved for use in CDA Release 2.0 Implementation Guides by organizations other than HL7 or its affiliates.

Extension	Definition	Defined/Used by
pcc:replacementOf	The <replacementOf> extension element is applied to a section appearing in a PHR Update Document to indicate that that section's content should replace that of a previously existing section. The identifier of the previously existing section is given so that the PHR Manager receiving the Update content will know which section to replace. The model for this extension is shown below. <pcc:replacementOf xmlns:pcc='urn:ihe:pcc:hl7v3'> <pcc:externalDocumentSection> <pcc:id root='58FCBE50-D4F2-4bda-BC1C-2105B284BBE3'/> <pcc:externalDocumentSection/> </pcc:replacementOf>	IHE PCC TF