The basic data structure consists of the following fields:
Basic Reference Set Data Structure |
Each is identified and named by a in the metadata hierarchy. Therefore the reference set is identified by a concept identifier (an ).
Each row in a reference set file represents a .
- Individual reference set members are uniquely identified by a identifier represented
as a
.
- Each reference set member belongs to a single reference set, and it is linked to that
reference set by the
field.
- Each reference set member is also associated with a single referenced component by
its
field. The referenced component may be a
,
,
. If the referenced component is a concept that identifies another reference set,
that reference set may be considered to be the target of the reference.
- Like
, reference set members can be versioned to inactivate or change the status of the
member. So there may be several rows in a
file and in this case the one with the most recent effectiveTime before or equal
to the point in time under consideration represents state of that reference set member.
If the
field of this row is false ('0'), then the reference set member is
at that point in time, which means that component it refers to is not a member of
the reference set. If the
field is true ('1'), then the component referenced by the
field is deemed to be a member of the
.
The and fields will not change between two rows with the same id, in other words they are immutable. Where a change is required to one of these fields, the current row will be inactivated (by appending a row with the same id and the field set to false). Another row with a new id will be appended to reference another component.
A component may belong to any number of . A component may also be referenced by more that one member of the same . This is not useful in the case of a simple reference set but is relevant for some reference sets. For example, a SNOMED CT concept may map to or from more than on codes in another code system.