7.4.1 Entity Identifiers
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.
An entity identifier opaquely represents the entity referenced in a clinical document.
It has no required relationship between the entity and the role that they play in
that document. Use of an entity identifier therefore gives CDA producing and consuming
applications a mechanism to unite the various entities represented in the CDA document,
and thereby expose relationships that would otherwise be obscured when entities cannot
be recognized as being identical. When two participants have the same entity identifier,
they can be assumed to be the same entity.
In the CDA Release 2.0 schema, organizations and the patient already carry an identifier
on the entity, and devices can have only one form of participation (as assignedAuthoringDevice).
Therefore, only those elements describing participant persons that are not the patient
need to support an element to identify the person. To state it simply, each person
that is represented by the CDA document that does not already have an id element may
now generate one if necessary using this extension. The identifier MAY be provided
in an id element from the urn:hl7-org:sdtc namespace.
This element SHALL be an instance identifier (II) and SHALL appear just before name
element of any person described by any role in the CDA Release 2.0 schema.
A document that identifies one person in this fashion SHOULD identify all persons
in this way, otherwise there will be unidentified persons described by the document,
and the utility of this extension will be negated.
Because the patient already supports an identifier element according to the CDA schema,
an additional id element is not necessary and SHOULD NOT be provided in the patient
element. However, to represent the patient in any other role, the identifier used
in the corresponding id element SHOULD be the same as the identifier used to represent
the patient.
CONF-537: An assignedPerson, informationRecipient, maintainingPerson, guardianPerson, relatedPerson, associatedPerson or subject
MAY include an id element from the urn:hl7-org:sdtc namespace to uniquely identify the person.
CONF-538: The id element SHALL use the instance identifier (II) data type.
CONF-539: The id element SHALL appear just before the name element of the entity.
Template CCD Person
Under pre-publication review
IHE Immunizations Entry (2014)
son)
error