This page is part of the FHIR Specification (v5.0.0: R5 - STU). This is the current published version in it's permanent home (it will always be available at this URL). For a full list of available versions, see the Directory of published versions . Page versions: R5 R4B R4 R3

4.3.2.185 CodeSystem http://hl7.org/fhir/filter-operator

Terminology Infrastructure Work Group

Maturity Level: N

Normative (from v4.0.0)

Use Context: Country: World

• Narrative
• XML
• JSON
• TTL

This Code system is used in the following value sets:

• ValueSet: Filter Operator (The kind of operation to perform as a part of a property based filter.)

4.3.2.185.1 Definition

The kind of operation to perform as a part of a property based filter.

4.3.2.185.2 Content

This code system http://hl7.org/fhir/filter-operator defines the following codes:

Code	Display	Definition	Comments	Copy
=	Equals	The specified property of the code equals the provided value.
is-a	Is A (by subsumption)	Includes all concept ids that have a transitive is-a relationship with the concept Id provided as the value, including the provided concept itself (include descendant codes and self).	The definition of is-a is that all the properties of the value are true for the specified property of the code, which means that a code has an is-a relationship with itself. To exclude the root code, use descendent-of
descendent-of	Descendent Of (by subsumption)	Includes all concept ids that have a transitive is-a relationship with the concept Id provided as the value, excluding the provided concept itself (i.e. include descendant codes only).	The definition of is-a is that all the properties of the value are true for the specified property of the code. Spelling note: "descendant" is a more correct spelling, but the spelling "descendent" is maintained in the code for backwards compatibility reasons
is-not-a	Not (Is A) (by subsumption)	The specified property of the code does not have an is-a relationship with the provided value.
regex	Regular Expression	The specified property of the code matches the regex specified in the provided value.
in	In Set	The specified property of the code is in the set of codes or concepts specified in the provided value (comma-separated list).
not-in	Not in Set	The specified property of the code is not in the set of codes or concepts specified in the provided value (comma-separated list).
generalizes	Generalizes (by Subsumption)	Includes all concept ids that have a transitive is-a relationship from the concept Id provided as the value, including the provided concept itself (i.e. include ancestor codes and self).	The definition of is-a is that all the properties of the value are true for the specified property of the code, which means that a code has an is-a relationship with itself. To exclude the root code, add it explicitly to as an exclude
child-of	Child Of	Only concepts with a direct hierarchical relationship to the index code and no other concepts. This does not include the index code in the output.
descendent-leaf	Descendent Leaf	Includes concept ids that have a transitive is-a relationship with the concept Id provided as the value, but which do not have any concept ids with transitive is-a relationships with themselves.
exists	Exists	The specified property of the code has at least one value (if the specified value is true; if the specified value is false, then matches when the specified property of the code has no values).

See the full registry of code systems defined as part of FHIR.

Explanation of the columns that may appear on this page: