Purpose

An 900000000000521006 |Association type reference set| represents a set of unordered associations of a particular type between .

Data structure

An is a used to represent associations between . Its structure is shown in the following table.

Table 50. Association reference Set - Data structure
Field	Data type	Purpose
id (field)	UUID (data type)	A 128 bit unsigned Integer (data type), uniquely identifying this . Different versions of a reference set member share the same id (field) but have different effectiveTime (field). This allows a reference set member to be modified or made active (field) (i.e. removed from the active set) at a specified time.
effectiveTime (field)	Time (data type)	The inclusive date or time at which this version of the identified became the current version. The current version of this at time T is the version with the most recent effectiveTime (field) prior to or equal to time T .
active (field)	Boolean (data type)	The state of the identified as at the specified effectiveTime (field) . If active (field) = 1 (true) the is part of the current version of the set, if active (field) = 0 (false) the is not part of the current version of the set.
moduleId (field)	SCTID (data type)	Identifies the that contains this as at the specified effectiveTime (field) . The value must be a of 900000000000443000 \|Module (core metadata concept)\| within the metadata .
refsetId (field)	SCTID (data type)	Identifies the to which this belongs. In this case, set to a of 900000000000521006 \|Association type reference set\| . This indicates the nature of the association between the source and target .
referencedComponentId (field)	SCTID (data type)	The identifier of the source of the association.
targetComponentId (field)	SCTID (data type)	The identifier of the target of the association.

Metadata

The following metadata in the "Foundation metadata " supports this :

900000000000455006 |Reference set|
- 900000000000521006 |Association type|
  - 900000000000522004 |Historical association|

Figure 16. Association Reference Sets in the Metadata Hierarchy

Notes on usage

Each member of a |Historical association| represents a Reference from an to other equivalent or related that were current in the in which that was inactivated.

Each |Historical association| holds of a different nature between the . The |Historical association| contains associations:

from each to one or more other that are current in the in which the was inactivated;
from each inactive for which there is a current replacement to the replacement ;
from an to a that is current in the in which the was inactivated, and which is correctly described by the Term of the ;
From each to one or more that replace it.

The identified by the targetComponentId (field) must be an instance of the same class of as the identified by the referencedComponentIdfor all |Historical association| apart from the |REFERS TO association |.

Within the |REFERS TO association |, the referenced ComponentId field must be a and the targetComponentIdmust be a .

The targetComponentId (field) is used differently in the |MOVED TO association |. In this case, the targetComponentId (field) does not refer directly to a replacement , but rather to the namespace to which the was moved to. The targetComponentId (field) actually refers to the that represents the namespace. This approach is used since the organization sourcing the may not always be able to determine the precise reference that is applicable in the receiving organization (namespace). Thus the responsibility for these references lies with the new responsible (receiving) organization.

See also more further information about 4.2.3 Historical Association Reference Sets.

Descriptor template and examples

The tables below show examples of the descriptors for specific that follow the 900000000000521006 |Association type reference set| pattern.

Table 51. Refset Descriptor rows for 900000000000527005 \|SAME AS association reference set\| .
refsetId	referencedComponentId (Referenced component)	attributeDescription (Attribute description)	attributeType (Attribute type)	attributeOrder (Attribute order)
900000000000456007 \|Reference set descriptor\|	900000000000527005 \|SAME AS association reference set\|	900000000000532006 \|Association source component\|	900000000000460005 \|Component type\|	0
900000000000456007 \|Reference set descriptor\|	900000000000527005 \|SAME AS association reference set\|	900000000000533001 \|Association target component\|	900000000000460005 \|Component type\|	1
Table 52. Refset Descriptor rows for 900000000000531004 \|REFERS TO concept association reference set\| .
refsetId	referencedComponentId (Referenced component)	attributeDescription (Attribute description)	attributeType (Attribute type)	attributeOrder (Attribute order)
900000000000456007 \|Reference set descriptor\|	900000000000531004 \|REFERS TO concept association reference set\|	900000000000532006 \|Association source component\|	900000000000460005 \|Component type\|	0
900000000000456007 \|Reference set descriptor\|	900000000000531004 \|REFERS TO concept association reference set\|	900000000000533001 \|Association target component\|	900000000000460005 \|Component type\|	1

Note: The tables above omit the initial four columns of data present in the release file. These follow the standards versioning pattern id (field), effectiveTime (field), active (field), active (field). Additionally, to aid understanding, the tables above also show the from one of the associated with each of the identified . The release file only contains the .

Association reference set example

The following table holds example entries for the |Replaced by| .

Table 53. Sample content from 900000000000526001 \|REPLACED BY association reference set\| .
refsetId	referencedComponentId (Association source component)	targetComponentId (Association target component)
900000000000526001 \|REPLACED BY association reference set\|	100005 \|SNOMED RT Concept\|	138875005 \|SNOMED CT Concept\|
900000000000526001 \|REPLACED BY association reference set\|	212002 \|Salmonella III arizonae 53:k:z\|	398450001 \|Salmonella IIIb 53:k:z\|
900000000000526001 \|REPLACED BY association reference set\|	225005 \|Special care of patient with contagious disease\|	133895001 \|Care of patient with infectious disease\|
900000000000526001 \|REPLACED BY association reference set\|	244003 \|Evans and Lloyd-Thomas syndrome\|	66659007 \|Normal variation in position\|
900000000000526001 \|REPLACED BY association reference set\|	278009 \|Epidural injection of neurolytic substance, lumbar\|	17753007 \|Epidural injection of neurolytic solution, lumbar\|
900000000000526001 \|REPLACED BY association reference set\|	558000 \|Other disorder of the neurohypophysis, NEC\|	72442006 \|Disorder of posterior pituitary\|
900000000000526001 \|REPLACED BY association reference set\|	659001 \|Peptostreptococcus anaerobius\|	413524006 \|Anaerococcus tretradius\|
900000000000526001 \|REPLACED BY association reference set\|	696005 \|Chronobiologic disorder\|	387605007 \|Abnormal chronobiologic state\|
900000000000526001 \|REPLACED BY association reference set\|	700002 \|Salmonella III arizonae 50:z4,z23,z32:--\|	404619004 \|Salmonella IIIa 50:z4,z23,z32:-\|
900000000000526001 \|REPLACED BY association reference set\|	822000 \|Salmonella arizonae 53:z4,z23:--\|	13998005 \|Salmonella IV 53:z4,z23:--\|