Vocabulary
![]() | Maturity Level : N | Normative (from v4.0.0) | Security Category : Anonymous | Compartments : Not linked to any defined compartments |
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This
page
has
been
approved
as
part
of
an
ANSI
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The CodeSystem resource is used to declare the existence of and describe a code system or code system supplement and its key properties, and optionally define a part or all of its content.
The
FHIR
terminology
specification
is
based
on
two
key
concepts,
originally
defined
in
HL7
v3
Core
Principles
:
CodeSystem
definitions
and
their
use
in
coded
elements
Code systems define which codes (symbols and/or expressions) exist, and how they are understood. Value sets select a set of codes from one or more code systems to specify which codes can be used in a particular context.
The CodeSystem resource is used to declare the existence of a code system, and its key properties:
In addition, the CodeSystem resource may list some or all of the concepts in the code system, along with their basic properties (code, display, definition), designations, and additional properties. Code System resources may also be used to define supplements, which extend an existing code system with additional designations and properties.
The CodeSystem resource is not intended to support the process of maintaining code systems. Instead, the focus is on publishing the properties and optionally the content of a code system for use throughout the FHIR eco-system, such as to support value set expansion and validation. Note that the important existing (large) code systems (SNOMED CT, LOINC, RxNorm, ICD family, etc.) all have their own maintenance systems and distribution formats, and CodeSystem is generally not an efficient way to distribute their content, though it is used as one way of declaring the filters and properties associated with those code systems.
The
CodeSystem
resource
declares
the
existence
of
a
code
system
and
its
key
properties
including
its
preferred
identifier.
The
NamingSystem
resource
identifies
the
existence
of
a
code
or
identifier
system,
and
its
possible
and
preferred
identifiers.
The
key
difference
between
the
resources
is
who
creates
and
manages
them
-
CodeSystem
resources
are
managed
by
the
owner
or
publisher
of
the
code
system,
who
can
properly
define
the
code
system
features
and
content.
NamingSystem
resources,
on
the
other
hand,
are
frequently
defined
by
3rd
parties
that
encounter
the
code
system
in
use,
and
need
to
describe
the
use,
but
do
not
have
the
authority
to
define
the
features
and
content.
Additionally,
there
may
be
multiple
authoritative
NamingSystem
resources
for
a
code
system,
but
ideally
there
would
be
only
one
authoritative
CodeSystem
resource
(identified
by
its
canonical
URL)
that
is
provided
by
the
code
system
publisher,
with
multiple
copies
distributed
on
additional
FHIR
servers
or
elsewhere
and
used
where
needed.
Both Code System supplements and Concept Maps may be used to define relationships between concepts in different systems. ConceptMaps are assertions of the relationships between different concepts that are associated with particular contexts of use, while CodeSystem supplements are used to define inherent properties and semantics of the concepts in the code system
When using code systems and value sets, proper differentiation between a code system and a value set is important. This is one very common area where significant clinical safety risks occur in practice. Implementers should be familiar with the content in Using Codes in Resources .
A code system has three identifiers. The first two can be used to reference the code system in the FHIR context:
CodeSystem.id
:
The
logical
id
on
the
system
that
holds
the
CodeSystem
resource
instance
-
this
typically
is
expected
to
change
as
the
resource
moves
from
server
to
server.
The
location
URI
is
constructed
by
appending
the
logical
id
to
the
server
base
address
where
the
instance
is
found
and
the
resource
type.
This
URI
should
be
a
resolvable
URL
by
which
the
resource
instance
may
be
retrieved,
usually
from
a
FHIR
server,
and
it
may
be
a
relative
reference
typically
to
the
server
base
URL.
CodeSystem.url
:
The
canonical
URL
that
never
changes
for
this
code
system
-
it
is
the
same
in
every
copy.
The
element
is
named
url
rather
than
uri
for
legacy
reasons
and
to
strongly
encourage
providing
a
resolvable
URL
as
the
identifier
whenever
possible.
This
canonical
URL
is
used
to
refer
to
all
instances
of
this
particular
code
system
across
all
servers
and
systems.
Ideally,
this
URI
should
be
a
URL
which
resolves
to
the
location
of
the
master
version
of
the
code
system,
though
this
is
not
always
possible.
For example, the code systems published as part of the FHIR specification all have a location ("literal") URI which is the URL where they may be accessed in the FHIR specification itself. However, while a new version of the FHIR specification is being prepared, code systems that are published in the drafts will not be found in the current FHIR specification version.
Because it is common practice to copy (cache) code systems locally, most references to code systems can use either the canonical URL or the location ("literal") URL.
The third code system identifier is used typically for external references to the code system outside of FHIR:
CodeSystem.identifier
:
A
system/value
pair
that
is
used
to
identify
the
code
system
in
other
contexts
(such
as
an
OID
in
an
HL7
v3
For further information regarding resource identification, see Resource Identity .
This
means
that
each
code
system
has
2
different
URIs
that
can
be
used
to
reference
it
-
its
canonical
URL
(the
url
element),
and
its
local
location
from
which
it
may
be
retrieved
(which
includes
the
id
element).
Because
it
is
common
practice
to
copy
(cache)
code
systems
locally,
most
references
to
code
systems
use
the
canonical
URL.
Alternatively,
the
identifier
and
version
elements
may
be
used
to
reference
this
code
system
in
a
design,
a
profile,
a
CDA
template
or
HL7
v3
message
(in
the
CD
data
type
codeSystem
and
codeSystemVersion
properties).
These
different
contexts
may
make
additional
restrictions
on
the
possible
values
of
these
elements.
The
identifier
is
generally
not
needed
when
using
code
systems
in
a
FHIR
context,
where
the
canonical
URL
is
always
the
focus.
This resource is referenced by Coding , itself, ConceptMap , TerminologyCapabilities and ValueSet .
This resource does not implement any patterns.
Structure
Name | Flags | Card. | Type |
Description
&
Constraints
![]() |
---|---|---|---|---|
![]() ![]() |
|
|
Declares
the
existence
of
and
describes
a
code
system
or
code
system
supplement
+ Warning: Name should be usable as an identifier for the module by machine processing applications such as code generation + Rule: Within a code system definition, all the codes SHALL be unique Elements defined in Ancestors: id , meta , implicitRules , language , text , contained , extension , modifierExtension , url , identifier , version , name , title , status , experimental , date , publisher , contact , description , useContext , jurisdiction , purpose , copyright | |
![]() ![]() ![]() | Σ | 0..1 | uri | Canonical identifier for this code system, represented as a URI (globally unique) (Coding.system) |
![]() ![]() ![]() | Σ | 0..* | Identifier |
Additional
identifier
for
the
code
system
(business
identifier)
|
![]() ![]() ![]() | Σ | 0..1 | string | Business version of the code system (Coding.version) |
![]() ![]() ![]() | Σ I | 0..1 | string | Name for this code system (computer friendly) |
![]() ![]() ![]() | Σ | 0..1 | string | Name for this code system (human friendly) |
![]() ![]() ![]() | ?! Σ | 1..1 | code |
draft
|
active
|
retired
|
unknown
PublicationStatus ( Required ) |
![]() ![]() ![]() | Σ | 0..1 | boolean | For testing purposes, not real usage |
![]() ![]() ![]() | Σ | 0..1 | dateTime | Date last changed |
![]() ![]() ![]() | Σ | 0..1 | string | Name of the publisher (organization or individual) |
![]() ![]() ![]() | Σ | 0..* | ContactDetail |
Contact
details
for
the
publisher
|
![]() ![]() ![]() | 0..1 | markdown | Natural language description of the code system | |
![]() ![]() ![]() | Σ TU | 0..* | UsageContext |
The
context
that
the
content
is
intended
to
support
|
![]() ![]() ![]() | Σ | 0..* | CodeableConcept |
Intended
jurisdiction
for
code
system
(if
applicable)
Jurisdiction ( Extensible ) |
![]() ![]() ![]() | 0..1 | markdown | Why this code system is defined | |
![]() ![]() ![]() | 0..1 | markdown | Use and/or publishing restrictions | |
![]() ![]() ![]() | Σ | 0..1 | boolean | If code comparison is case sensitive |
![]() ![]() ![]() | Σ | 0..1 | canonical ( ValueSet ) | Canonical reference to the value set with entire code system |
![]() ![]() ![]() | Σ | 0..1 | code |
grouped-by
|
is-a
|
part-of
|
classified-with
CodeSystemHierarchyMeaning ( Required ) |
![]() ![]() ![]() | Σ | 0..1 | boolean | If code system defines a compositional grammar |
![]() ![]() ![]() | Σ | 0..1 | boolean | If definitions are not stable |
![]() ![]() ![]() | Σ | 1..1 | code |
not-present
|
example
|
fragment
|
complete
|
supplement
CodeSystemContentMode ( Required ) |
![]() ![]() ![]() | Σ | 0..1 | canonical ( CodeSystem ) | Canonical URL of Code System this adds designations and properties to |
![]() ![]() ![]() | Σ | 0..1 | unsignedInt | Total concepts in the code system |
![]() ![]() ![]() | Σ | 0..* | BackboneElement |
Filter
that
can
be
used
in
a
value
set
|
![]() ![]() ![]() ![]() | Σ | 1..1 | code | Code that identifies the filter |
![]() ![]() ![]() ![]() | Σ | 0..1 | string | How or why the filter is used |
![]() ![]() ![]() ![]() | Σ | 1..* | code |
=
|
is-a
|
descendent-of
|
is-not-a
|
regex
|
in
|
not-in
|
generalizes
|
exists
FilterOperator ( Required ) |
![]() ![]() ![]() ![]() | Σ | 1..1 | string | What to use for the value |
![]() ![]() ![]() | Σ | 0..* | BackboneElement |
Additional
information
supplied
about
each
concept
|
![]() ![]() ![]() ![]() | Σ | 1..1 | code | Identifies the property on the concepts, and when referred to in operations |
![]() ![]() ![]() ![]() | Σ | 0..1 | uri | Formal identifier for the property |
![]() ![]() ![]() ![]() | Σ | 0..1 | string | Why the property is defined, and/or what it conveys |
![]() ![]() ![]() ![]() | Σ | 1..1 | code |
code
|
Coding
|
string
|
integer
|
boolean
|
dateTime
|
decimal
PropertyType ( Required ) |
![]() ![]() ![]() | 0..* | BackboneElement |
Concepts
in
the
code
system
| |
![]() ![]() ![]() ![]() | 1..1 | code | Code that identifies concept | |
![]() ![]() ![]() ![]() | 0..1 | string | Text to display to the user | |
![]() ![]() ![]() ![]() | 0..1 | string | Formal definition | |
![]() ![]() ![]() ![]() | 0..* | BackboneElement |
Additional
representations
for
the
concept
| |
![]() ![]() ![]() ![]() ![]() | 0..1 | code |
Human
language
of
the
designation
Common Languages ( Preferred but limited to AllLanguages ) | |
![]() ![]() ![]() ![]() ![]() | 0..1 | Coding |
Details
how
this
designation
would
be
used
Designation Use ( Extensible ) | |
![]() ![]() ![]() ![]() ![]() | 1..1 | string | The text value for this designation | |
![]() ![]() ![]() ![]() | 0..* | BackboneElement |
Property
value
for
the
concept
| |
![]() ![]() ![]() ![]() ![]() | 1..1 | code | Reference to CodeSystem.property.code | |
![]() ![]() ![]() ![]() ![]() | 1..1 | Value of the property for this concept | ||
![]() ![]() ![]() ![]() ![]() ![]() | code | |||
![]() ![]() ![]() ![]() ![]() ![]() | Coding | |||
![]() ![]() ![]() ![]() ![]() ![]() | string | |||
![]() ![]() ![]() ![]() ![]() ![]() | integer | |||
![]() ![]() ![]() ![]() ![]() ![]() | boolean | |||
![]() ![]() ![]() ![]() ![]() ![]() | dateTime | |||
![]() ![]() ![]() ![]() ![]() ![]() | decimal | |||
![]() ![]() ![]() ![]() | 0..* | see concept |
Child
Concepts
(is-a/contains/categorizes)
| |
![]() |
UML Diagram ( Legend )
XML Template
<CodeSystem xmlns="http://hl7.org/fhir"><!-- from Resource: id, meta, implicitRules, and language -->
<!-- from --><url value="[uri]"/><!-- 0..1 Canonical identifier for this code system, represented as a URI (globally unique) (Coding.system) --> <identifier><!-- 0..* Identifier Additional identifier for the code system (business identifier) --></identifier> <version value="[string]"/><!-- 0..1 Business version of the code system (Coding.version) --><<name value="[string]"/><!--0..1 Name for this code system (computer friendly) --> <title value="[string]"/><!-- 0..1 Name for this code system (human friendly) --> <status value="[code]"/><!-- 1..1 draft | active | retired | unknown --> <experimental value="[boolean]"/><!-- 0..1 For testing purposes, not real usage --> <date value="[dateTime]"/><!-- 0..1 Date last changed --> <publisher value="[string]"/><!-- 0..1 Name of the publisher (organization or individual) --> <contact><!-- 0..* ContactDetail Contact details for the publisher --></contact> <description value="[markdown]"/><!-- 0..1 Natural language description of the code system --> <useContext><!-- 0..* UsageContext The context that the content is intended to support --></useContext> <jurisdiction><!-- 0..* CodeableConcept Intended jurisdiction for code system (if applicable) --></jurisdiction> <purpose value="[markdown]"/><!-- 0..1 Why this code system is defined --> <copyright value="[markdown]"/><!-- 0..1 Use and/or publishing restrictions --> <caseSensitive value="[boolean]"/><!-- 0..1 If code comparison is case sensitive --> <valueSet><!-- 0..1 canonical(ValueSet) Canonical reference to the value set with entire code system --></valueSet> <hierarchyMeaning value="[code]"/><!-- 0..1 grouped-by | is-a | part-of | classified-with --> <compositional value="[boolean]"/><!-- 0..1 If code system defines a compositional grammar --> <versionNeeded value="[boolean]"/><!-- 0..1 If definitions are not stable --> <content value="[code]"/><!-- 1..1 not-present | example | fragment | complete | supplement --> <supplements><!-- 0..1 canonical(CodeSystem) Canonical URL of Code System this adds designations and properties to --></supplements> <count value="[unsignedInt]"/><!-- 0..1 Total concepts in the code system --> <filter> <!-- 0..* Filter that can be used in a value set -->
<<code value="[code]"/><!-- 1..1 Code that identifies the filter --> <description value="[string]"/><!-- 0..1 How or why the filter is used --> <operator value="[code]"/><!-- 1..* = | is-a | descendent-of | is-not-a | regex | in | not-in | generalizes | exists --> <value value="[string]"/><!-- 1..1 What to use for the value --> </filter> <property> <!-- 0..* Additional information supplied about each concept --> <code value="[code]"/><!-- 1..1 Identifies the property on the concepts, and when referred to in operations --> <uri value="[uri]"/><!-- 0..1 Formal identifier for the property --> <description value="[string]"/><!-- 0..1 Why the property is defined, and/or what it conveys --> <type value="[code]"/><!-- 1..1 code | Coding | string | integer | boolean | dateTime | decimal --> </property> <concept> <!-- 0..* Concepts in the code system --> <code value="[code]"/><!-- 1..1 Code that identifies concept --> <display value="[string]"/><!-- 0..1 Text to display to the user --> <definition value="[string]"/><!-- 0..1 Formal definition --> <designation> <!-- 0..* Additional representations for the concept --> <language value="[code]"/><!-- 0..1 Human language of the designation --> <use><!-- 0..1 Coding Details how this designation would be used --></use> <value value="[string]"/><!-- 1..1 The text value for this designation --> </designation> <property> <!-- 0..* Property value for the concept --> <code value="[code]"/><!-- 1..1 Reference to CodeSystem.property.code --> <value[x]><!-- 1..1 code|Coding|string|integer|boolean|dateTime|decimal Value of the property for this concept --></value[x]> </property> <concept><!-- 0..* Content as for CodeSystem.concept Child Concepts (is-a/contains/categorizes) --></concept> </concept> </CodeSystem>
JSON Template
{"resourceType" : "CodeSystem", // from Resource: id, meta, implicitRules, and language
// from"url" : "<uri>", // Canonical identifier for this code system, represented as a URI (globally unique) (Coding.system) "identifier" : [{ Identifier }], // Additional identifier for the code system (business identifier) "version" : "<string>", // Business version of the code system (Coding.version)""name" : "<string>", // C? Name for this code system (computer friendly) "title" : "<string>", // Name for this code system (human friendly) "status" : "<code>", // R! draft | active | retired | unknown "experimental" : <boolean>, // For testing purposes, not real usage "date" : "<dateTime>", // Date last changed "publisher" : "<string>", // Name of the publisher (organization or individual) "contact" : [{ ContactDetail }], // Contact details for the publisher "description" : "<markdown>", // Natural language description of the code system "useContext" : [{ UsageContext }], // The context that the content is intended to support "jurisdiction" : [{ CodeableConcept }], // Intended jurisdiction for code system (if applicable) "purpose" : "<markdown>", // Why this code system is defined "copyright" : "<markdown>", // Use and/or publishing restrictions "caseSensitive" : <boolean>, // If code comparison is case sensitive "valueSet" : { canonical(ValueSet) }, // Canonical reference to the value set with entire code system "hierarchyMeaning" : "<code>", // grouped-by | is-a | part-of | classified-with "compositional" : <boolean>, // If code system defines a compositional grammar "versionNeeded" : <boolean>, // If definitions are not stable "content" : "<code>", // R! not-present | example | fragment | complete | supplement "supplements" : { canonical(CodeSystem) }, // Canonical URL of Code System this adds designations and properties to "count" : "<unsignedInt>", // Total concepts in the code system "filter" : [{ // Filter that can be used in a value set""code" : "<code>", // R! Code that identifies the filter "description" : "<string>", // How or why the filter is used "operator" : ["<code>"], // R! = | is-a | descendent-of | is-not-a | regex | in | not-in | generalizes | exists "value" : "<string>" // R! What to use for the value }], "property" : [{ // Additional information supplied about each concept "code" : "<code>", // R! Identifies the property on the concepts, and when referred to in operations "uri" : "<uri>", // Formal identifier for the property "description" : "<string>", // Why the property is defined, and/or what it conveys "type" : "<code>" // R! code | Coding | string | integer | boolean | dateTime | decimal }], "concept" : [{ // Concepts in the code system "code" : "<code>", // R! Code that identifies concept "display" : "<string>", // Text to display to the user "definition" : "<string>", // Formal definition "designation" : [{ // Additional representations for the concept "language" : "<code>", // Human language of the designation "use" : { Coding }, // Details how this designation would be used "value" : "<string>" // R! The text value for this designation }], "property" : [{ // Property value for the concept "code" : "<code>", // R! Reference to CodeSystem.property.code // value[x]: Value of the property for this concept. One of these 7: "valueCode" : "<code>" "valueCoding" : { Coding } "valueString" : "<string>" "valueInteger" : <integer> "valueBoolean" : <boolean> "valueDateTime" : "<dateTime>" "valueDecimal" : <decimal> }], "concept" : [{ Content as for CodeSystem.concept }] // Child Concepts (is-a/contains/categorizes) }] }
Turtle Template
@prefix fhir: <http://hl7.org/fhir/> .[ a fhir:CodeSystem; fhir:nodeRole fhir:treeRoot; # if this is the parser root # from Resource: .id, .meta, .implicitRules, and .language
# fromfhir:CodeSystem.url [ uri ]; # 0..1 Canonical identifier for this code system, represented as a URI (globally unique) (Coding.system) fhir:CodeSystem.identifier [ Identifier ], ... ; # 0..* Additional identifier for the code system (business identifier) fhir:CodeSystem.version [ string ]; # 0..1 Business version of the code system (Coding.version) fhir:CodeSystem.name [ string ]; # 0..1 Name for this code system (computer friendly) fhir:CodeSystem.title [ string ]; # 0..1 Name for this code system (human friendly) fhir:CodeSystem.status [ code ]; # 1..1 draft | active | retired | unknown fhir:CodeSystem.experimental [ boolean ]; # 0..1 For testing purposes, not real usage fhir:CodeSystem.date [ dateTime ]; # 0..1 Date last changed fhir:CodeSystem.publisher [ string ]; # 0..1 Name of the publisher (organization or individual) fhir:CodeSystem.contact [ ContactDetail ], ... ; # 0..* Contact details for the publisher fhir:CodeSystem.description [ markdown ]; # 0..1 Natural language description of the code system fhir:CodeSystem.useContext [ UsageContext ], ... ; # 0..* The context that the content is intended to support fhir:CodeSystem.jurisdiction [ CodeableConcept ], ... ; # 0..* Intended jurisdiction for code system (if applicable) fhir:CodeSystem.purpose [ markdown ]; # 0..1 Why this code system is defined fhir:CodeSystem.copyright [ markdown ]; # 0..1 Use and/or publishing restrictions fhir:CodeSystem.caseSensitive [ boolean ]; # 0..1 If code comparison is case sensitive fhir:CodeSystem.valueSet [ canonical(ValueSet) ]; # 0..1 Canonical reference to the value set with entire code system fhir:CodeSystem.hierarchyMeaning [ code ]; # 0..1 grouped-by | is-a | part-of | classified-with fhir:CodeSystem.compositional [ boolean ]; # 0..1 If code system defines a compositional grammar fhir:CodeSystem.versionNeeded [ boolean ]; # 0..1 If definitions are not stable fhir:CodeSystem.content [ code ]; # 1..1 not-present | example | fragment | complete | supplement fhir:CodeSystem.supplements [ canonical(CodeSystem) ]; # 0..1 Canonical URL of Code System this adds designations and properties to fhir:CodeSystem.count [ unsignedInt ]; # 0..1 Total concepts in the code system fhir:CodeSystem.filter [ # 0..* Filter that can be used in a value setfhir:fhir:CodeSystem.filter.code [ code ]; # 1..1 Code that identifies the filter fhir:CodeSystem.filter.description [ string ]; # 0..1 How or why the filter is used fhir:CodeSystem.filter.operator [ code ], ... ; # 1..* = | is-a | descendent-of | is-not-a | regex | in | not-in | generalizes | exists fhir:CodeSystem.filter.value [ string ]; # 1..1 What to use for the value ], ...; fhir:CodeSystem.property [ # 0..* Additional information supplied about each concept fhir:CodeSystem.property.code [ code ]; # 1..1 Identifies the property on the concepts, and when referred to in operations fhir:CodeSystem.property.uri [ uri ]; # 0..1 Formal identifier for the property fhir:CodeSystem.property.description [ string ]; # 0..1 Why the property is defined, and/or what it conveys fhir:CodeSystem.property.type [ code ]; # 1..1 code | Coding | string | integer | boolean | dateTime | decimal ], ...; fhir:CodeSystem.concept [ # 0..* Concepts in the code system fhir:CodeSystem.concept.code [ code ]; # 1..1 Code that identifies concept fhir:CodeSystem.concept.display [ string ]; # 0..1 Text to display to the user fhir:CodeSystem.concept.definition [ string ]; # 0..1 Formal definition fhir:CodeSystem.concept.designation [ # 0..* Additional representations for the concept fhir:CodeSystem.concept.designation.language [ code ]; # 0..1 Human language of the designation fhir:CodeSystem.concept.designation.use [ Coding ]; # 0..1 Details how this designation would be used fhir:CodeSystem.concept.designation.value [ string ]; # 1..1 The text value for this designation ], ...; fhir:CodeSystem.concept.property [ # 0..* Property value for the concept fhir:CodeSystem.concept.property.code [ code ]; # 1..1 Reference to CodeSystem.property.code # CodeSystem.concept.property.value[x] : 1..1 Value of the property for this concept. One of these 7 fhir:CodeSystem.concept.property.valueCode [ code ] fhir:CodeSystem.concept.property.valueCoding [ Coding ] fhir:CodeSystem.concept.property.valueString [ string ] fhir:CodeSystem.concept.property.valueInteger [ integer ] fhir:CodeSystem.concept.property.valueBoolean [ boolean ] fhir:CodeSystem.concept.property.valueDateTime [ dateTime ] fhir:CodeSystem.concept.property.valueDecimal [ decimal ] ], ...; fhir:CodeSystem.concept.concept [ See CodeSystem.concept ], ... ; # 0..* Child Concepts (is-a/contains/categorizes) ], ...; ]
Changes since R3
CodeSystem | |
|
|
CodeSystem.hierarchyMeaning |
|
CodeSystem.content |
|
CodeSystem.filter.operator |
|
CodeSystem.property.type |
|
See the Full Difference for further information
This analysis is available as XML or JSON .
See R3 <--> R4 Conversion Maps (status = 4 tests that all execute ok. All tests pass round-trip testing and 3 r3 resources are invalid (0 errors). )
Structure
Name | Flags | Card. | Type |
Description
&
Constraints
![]() |
---|---|---|---|---|
![]() ![]() |
|
|
Declares
the
existence
of
and
describes
a
code
system
or
code
system
supplement
+ Warning: Name should be usable as an identifier for the module by machine processing applications such as code generation + Rule: Within a code system definition, all the codes SHALL be unique Elements defined in Ancestors: id , meta , implicitRules , language , text , contained , extension , modifierExtension , url , identifier , version , name , title , status , experimental , date , publisher , contact , description , useContext , jurisdiction , purpose , copyright | |
![]() ![]() ![]() | Σ | 0..1 | uri | Canonical identifier for this code system, represented as a URI (globally unique) (Coding.system) |
![]() ![]() ![]() | Σ | 0..* | Identifier |
Additional
identifier
for
the
code
system
(business
identifier)
|
![]() ![]() ![]() | Σ | 0..1 | string | Business version of the code system (Coding.version) |
![]() ![]() ![]() | Σ I | 0..1 | string | Name for this code system (computer friendly) |
![]() ![]() ![]() | Σ | 0..1 | string | Name for this code system (human friendly) |
![]() ![]() ![]() | ?! Σ | 1..1 | code |
draft
|
active
|
retired
|
unknown
PublicationStatus ( Required ) |
![]() ![]() ![]() | Σ | 0..1 | boolean | For testing purposes, not real usage |
![]() ![]() ![]() | Σ | 0..1 | dateTime | Date last changed |
![]() ![]() ![]() | Σ | 0..1 | string | Name of the publisher (organization or individual) |
![]() ![]() ![]() | Σ | 0..* | ContactDetail |
Contact
details
for
the
publisher
|
![]() ![]() ![]() | 0..1 | markdown | Natural language description of the code system | |
![]() ![]() ![]() | Σ TU | 0..* | UsageContext |
The
context
that
the
content
is
intended
to
support
|
![]() ![]() ![]() | Σ | 0..* | CodeableConcept |
Intended
jurisdiction
for
code
system
(if
applicable)
Jurisdiction ( Extensible ) |
![]() ![]() ![]() | 0..1 | markdown | Why this code system is defined | |
![]() ![]() ![]() | 0..1 | markdown | Use and/or publishing restrictions | |
![]() ![]() ![]() | Σ | 0..1 | boolean | If code comparison is case sensitive |
![]() ![]() ![]() | Σ | 0..1 | canonical ( ValueSet ) | Canonical reference to the value set with entire code system |
![]() ![]() ![]() | Σ | 0..1 | code |
grouped-by
|
is-a
|
part-of
|
classified-with
CodeSystemHierarchyMeaning ( Required ) |
![]() ![]() ![]() | Σ | 0..1 | boolean | If code system defines a compositional grammar |
![]() ![]() ![]() | Σ | 0..1 | boolean | If definitions are not stable |
![]() ![]() ![]() | Σ | 1..1 | code |
not-present
|
example
|
fragment
|
complete
|
supplement
CodeSystemContentMode ( Required ) |
![]() ![]() ![]() | Σ | 0..1 | canonical ( CodeSystem ) | Canonical URL of Code System this adds designations and properties to |
![]() ![]() ![]() | Σ | 0..1 | unsignedInt | Total concepts in the code system |
![]() ![]() ![]() | Σ | 0..* | BackboneElement |
Filter
that
can
be
used
in
a
value
set
|
![]() ![]() ![]() ![]() | Σ | 1..1 | code | Code that identifies the filter |
![]() ![]() ![]() ![]() | Σ | 0..1 | string | How or why the filter is used |
![]() ![]() ![]() ![]() | Σ | 1..* | code |
=
|
is-a
|
descendent-of
|
is-not-a
|
regex
|
in
|
not-in
|
generalizes
|
exists
FilterOperator ( Required ) |
![]() ![]() ![]() ![]() | Σ | 1..1 | string | What to use for the value |
![]() ![]() ![]() | Σ | 0..* | BackboneElement |
Additional
information
supplied
about
each
concept
|
![]() ![]() ![]() ![]() | Σ | 1..1 | code | Identifies the property on the concepts, and when referred to in operations |
![]() ![]() ![]() ![]() | Σ | 0..1 | uri | Formal identifier for the property |
![]() ![]() ![]() ![]() | Σ | 0..1 | string | Why the property is defined, and/or what it conveys |
![]() ![]() ![]() ![]() | Σ | 1..1 | code |
code
|
Coding
|
string
|
integer
|
boolean
|
dateTime
|
decimal
PropertyType ( Required ) |
![]() ![]() ![]() | 0..* | BackboneElement |
Concepts
in
the
code
system
| |
![]() ![]() ![]() ![]() | 1..1 | code | Code that identifies concept | |
![]() ![]() ![]() ![]() | 0..1 | string | Text to display to the user | |
![]() ![]() ![]() ![]() | 0..1 | string | Formal definition | |
![]() ![]() ![]() ![]() | 0..* | BackboneElement |
Additional
representations
for
the
concept
| |
![]() ![]() ![]() ![]() ![]() | 0..1 | code |
Human
language
of
the
designation
Common Languages ( Preferred but limited to AllLanguages ) | |
![]() ![]() ![]() ![]() ![]() | 0..1 | Coding |
Details
how
this
designation
would
be
used
Designation Use ( Extensible ) | |
![]() ![]() ![]() ![]() ![]() | 1..1 | string | The text value for this designation | |
![]() ![]() ![]() ![]() | 0..* | BackboneElement |
Property
value
for
the
concept
| |
![]() ![]() ![]() ![]() ![]() | 1..1 | code | Reference to CodeSystem.property.code | |
![]() ![]() ![]() ![]() ![]() | 1..1 | Value of the property for this concept | ||
![]() ![]() ![]() ![]() ![]() ![]() | code | |||
![]() ![]() ![]() ![]() ![]() ![]() | Coding | |||
![]() ![]() ![]() ![]() ![]() ![]() | string | |||
![]() ![]() ![]() ![]() ![]() ![]() | integer | |||
![]() ![]() ![]() ![]() ![]() ![]() | boolean | |||
![]() ![]() ![]() ![]() ![]() ![]() | dateTime | |||
![]() ![]() ![]() ![]() ![]() ![]() | decimal | |||
![]() ![]() ![]() ![]() | 0..* | see concept |
Child
Concepts
(is-a/contains/categorizes)
| |
![]() |
XML Template
<CodeSystem xmlns="http://hl7.org/fhir"><!-- from Resource: id, meta, implicitRules, and language -->
<!-- from --><url value="[uri]"/><!-- 0..1 Canonical identifier for this code system, represented as a URI (globally unique) (Coding.system) --> <identifier><!-- 0..* Identifier Additional identifier for the code system (business identifier) --></identifier> <version value="[string]"/><!-- 0..1 Business version of the code system (Coding.version) --><<name value="[string]"/><!--0..1 Name for this code system (computer friendly) --> <title value="[string]"/><!-- 0..1 Name for this code system (human friendly) --> <status value="[code]"/><!-- 1..1 draft | active | retired | unknown --> <experimental value="[boolean]"/><!-- 0..1 For testing purposes, not real usage --> <date value="[dateTime]"/><!-- 0..1 Date last changed --> <publisher value="[string]"/><!-- 0..1 Name of the publisher (organization or individual) --> <contact><!-- 0..* ContactDetail Contact details for the publisher --></contact> <description value="[markdown]"/><!-- 0..1 Natural language description of the code system --> <useContext><!-- 0..* UsageContext The context that the content is intended to support --></useContext> <jurisdiction><!-- 0..* CodeableConcept Intended jurisdiction for code system (if applicable) --></jurisdiction> <purpose value="[markdown]"/><!-- 0..1 Why this code system is defined --> <copyright value="[markdown]"/><!-- 0..1 Use and/or publishing restrictions --> <caseSensitive value="[boolean]"/><!-- 0..1 If code comparison is case sensitive --> <valueSet><!-- 0..1 canonical(ValueSet) Canonical reference to the value set with entire code system --></valueSet> <hierarchyMeaning value="[code]"/><!-- 0..1 grouped-by | is-a | part-of | classified-with --> <compositional value="[boolean]"/><!-- 0..1 If code system defines a compositional grammar --> <versionNeeded value="[boolean]"/><!-- 0..1 If definitions are not stable --> <content value="[code]"/><!-- 1..1 not-present | example | fragment | complete | supplement --> <supplements><!-- 0..1 canonical(CodeSystem) Canonical URL of Code System this adds designations and properties to --></supplements> <count value="[unsignedInt]"/><!-- 0..1 Total concepts in the code system --> <filter> <!-- 0..* Filter that can be used in a value set -->
<<code value="[code]"/><!-- 1..1 Code that identifies the filter --> <description value="[string]"/><!-- 0..1 How or why the filter is used --> <operator value="[code]"/><!-- 1..* = | is-a | descendent-of | is-not-a | regex | in | not-in | generalizes | exists --> <value value="[string]"/><!-- 1..1 What to use for the value --> </filter> <property> <!-- 0..* Additional information supplied about each concept --> <code value="[code]"/><!-- 1..1 Identifies the property on the concepts, and when referred to in operations --> <uri value="[uri]"/><!-- 0..1 Formal identifier for the property --> <description value="[string]"/><!-- 0..1 Why the property is defined, and/or what it conveys --> <type value="[code]"/><!-- 1..1 code | Coding | string | integer | boolean | dateTime | decimal --> </property> <concept> <!-- 0..* Concepts in the code system --> <code value="[code]"/><!-- 1..1 Code that identifies concept --> <display value="[string]"/><!-- 0..1 Text to display to the user --> <definition value="[string]"/><!-- 0..1 Formal definition --> <designation> <!-- 0..* Additional representations for the concept --> <language value="[code]"/><!-- 0..1 Human language of the designation --> <use><!-- 0..1 Coding Details how this designation would be used --></use> <value value="[string]"/><!-- 1..1 The text value for this designation --> </designation> <property> <!-- 0..* Property value for the concept --> <code value="[code]"/><!-- 1..1 Reference to CodeSystem.property.code --> <value[x]><!-- 1..1 code|Coding|string|integer|boolean|dateTime|decimal Value of the property for this concept --></value[x]> </property> <concept><!-- 0..* Content as for CodeSystem.concept Child Concepts (is-a/contains/categorizes) --></concept> </concept> </CodeSystem>
JSON Template
{"resourceType" : "CodeSystem", // from Resource: id, meta, implicitRules, and language
// from"url" : "<uri>", // Canonical identifier for this code system, represented as a URI (globally unique) (Coding.system) "identifier" : [{ Identifier }], // Additional identifier for the code system (business identifier) "version" : "<string>", // Business version of the code system (Coding.version)""name" : "<string>", // C? Name for this code system (computer friendly) "title" : "<string>", // Name for this code system (human friendly) "status" : "<code>", // R! draft | active | retired | unknown "experimental" : <boolean>, // For testing purposes, not real usage "date" : "<dateTime>", // Date last changed "publisher" : "<string>", // Name of the publisher (organization or individual) "contact" : [{ ContactDetail }], // Contact details for the publisher "description" : "<markdown>", // Natural language description of the code system "useContext" : [{ UsageContext }], // The context that the content is intended to support "jurisdiction" : [{ CodeableConcept }], // Intended jurisdiction for code system (if applicable) "purpose" : "<markdown>", // Why this code system is defined "copyright" : "<markdown>", // Use and/or publishing restrictions "caseSensitive" : <boolean>, // If code comparison is case sensitive "valueSet" : { canonical(ValueSet) }, // Canonical reference to the value set with entire code system "hierarchyMeaning" : "<code>", // grouped-by | is-a | part-of | classified-with "compositional" : <boolean>, // If code system defines a compositional grammar "versionNeeded" : <boolean>, // If definitions are not stable "content" : "<code>", // R! not-present | example | fragment | complete | supplement "supplements" : { canonical(CodeSystem) }, // Canonical URL of Code System this adds designations and properties to "count" : "<unsignedInt>", // Total concepts in the code system "filter" : [{ // Filter that can be used in a value set""code" : "<code>", // R! Code that identifies the filter "description" : "<string>", // How or why the filter is used "operator" : ["<code>"], // R! = | is-a | descendent-of | is-not-a | regex | in | not-in | generalizes | exists "value" : "<string>" // R! What to use for the value }], "property" : [{ // Additional information supplied about each concept "code" : "<code>", // R! Identifies the property on the concepts, and when referred to in operations "uri" : "<uri>", // Formal identifier for the property "description" : "<string>", // Why the property is defined, and/or what it conveys "type" : "<code>" // R! code | Coding | string | integer | boolean | dateTime | decimal }], "concept" : [{ // Concepts in the code system "code" : "<code>", // R! Code that identifies concept "display" : "<string>", // Text to display to the user "definition" : "<string>", // Formal definition "designation" : [{ // Additional representations for the concept "language" : "<code>", // Human language of the designation "use" : { Coding }, // Details how this designation would be used "value" : "<string>" // R! The text value for this designation }], "property" : [{ // Property value for the concept "code" : "<code>", // R! Reference to CodeSystem.property.code // value[x]: Value of the property for this concept. One of these 7: "valueCode" : "<code>" "valueCoding" : { Coding } "valueString" : "<string>" "valueInteger" : <integer> "valueBoolean" : <boolean> "valueDateTime" : "<dateTime>" "valueDecimal" : <decimal> }], "concept" : [{ Content as for CodeSystem.concept }] // Child Concepts (is-a/contains/categorizes) }] }
Turtle Template
@prefix fhir: <http://hl7.org/fhir/> .[ a fhir:CodeSystem; fhir:nodeRole fhir:treeRoot; # if this is the parser root # from Resource: .id, .meta, .implicitRules, and .language
# fromfhir:CodeSystem.url [ uri ]; # 0..1 Canonical identifier for this code system, represented as a URI (globally unique) (Coding.system) fhir:CodeSystem.identifier [ Identifier ], ... ; # 0..* Additional identifier for the code system (business identifier) fhir:CodeSystem.version [ string ]; # 0..1 Business version of the code system (Coding.version) fhir:CodeSystem.name [ string ]; # 0..1 Name for this code system (computer friendly) fhir:CodeSystem.title [ string ]; # 0..1 Name for this code system (human friendly) fhir:CodeSystem.status [ code ]; # 1..1 draft | active | retired | unknown fhir:CodeSystem.experimental [ boolean ]; # 0..1 For testing purposes, not real usage fhir:CodeSystem.date [ dateTime ]; # 0..1 Date last changed fhir:CodeSystem.publisher [ string ]; # 0..1 Name of the publisher (organization or individual) fhir:CodeSystem.contact [ ContactDetail ], ... ; # 0..* Contact details for the publisher fhir:CodeSystem.description [ markdown ]; # 0..1 Natural language description of the code system fhir:CodeSystem.useContext [ UsageContext ], ... ; # 0..* The context that the content is intended to support fhir:CodeSystem.jurisdiction [ CodeableConcept ], ... ; # 0..* Intended jurisdiction for code system (if applicable) fhir:CodeSystem.purpose [ markdown ]; # 0..1 Why this code system is defined fhir:CodeSystem.copyright [ markdown ]; # 0..1 Use and/or publishing restrictions fhir:CodeSystem.caseSensitive [ boolean ]; # 0..1 If code comparison is case sensitive fhir:CodeSystem.valueSet [ canonical(ValueSet) ]; # 0..1 Canonical reference to the value set with entire code system fhir:CodeSystem.hierarchyMeaning [ code ]; # 0..1 grouped-by | is-a | part-of | classified-with fhir:CodeSystem.compositional [ boolean ]; # 0..1 If code system defines a compositional grammar fhir:CodeSystem.versionNeeded [ boolean ]; # 0..1 If definitions are not stable fhir:CodeSystem.content [ code ]; # 1..1 not-present | example | fragment | complete | supplement fhir:CodeSystem.supplements [ canonical(CodeSystem) ]; # 0..1 Canonical URL of Code System this adds designations and properties to fhir:CodeSystem.count [ unsignedInt ]; # 0..1 Total concepts in the code system fhir:CodeSystem.filter [ # 0..* Filter that can be used in a value setfhir:fhir:CodeSystem.filter.code [ code ]; # 1..1 Code that identifies the filter fhir:CodeSystem.filter.description [ string ]; # 0..1 How or why the filter is used fhir:CodeSystem.filter.operator [ code ], ... ; # 1..* = | is-a | descendent-of | is-not-a | regex | in | not-in | generalizes | exists fhir:CodeSystem.filter.value [ string ]; # 1..1 What to use for the value ], ...; fhir:CodeSystem.property [ # 0..* Additional information supplied about each concept fhir:CodeSystem.property.code [ code ]; # 1..1 Identifies the property on the concepts, and when referred to in operations fhir:CodeSystem.property.uri [ uri ]; # 0..1 Formal identifier for the property fhir:CodeSystem.property.description [ string ]; # 0..1 Why the property is defined, and/or what it conveys fhir:CodeSystem.property.type [ code ]; # 1..1 code | Coding | string | integer | boolean | dateTime | decimal ], ...; fhir:CodeSystem.concept [ # 0..* Concepts in the code system fhir:CodeSystem.concept.code [ code ]; # 1..1 Code that identifies concept fhir:CodeSystem.concept.display [ string ]; # 0..1 Text to display to the user fhir:CodeSystem.concept.definition [ string ]; # 0..1 Formal definition fhir:CodeSystem.concept.designation [ # 0..* Additional representations for the concept fhir:CodeSystem.concept.designation.language [ code ]; # 0..1 Human language of the designation fhir:CodeSystem.concept.designation.use [ Coding ]; # 0..1 Details how this designation would be used fhir:CodeSystem.concept.designation.value [ string ]; # 1..1 The text value for this designation ], ...; fhir:CodeSystem.concept.property [ # 0..* Property value for the concept fhir:CodeSystem.concept.property.code [ code ]; # 1..1 Reference to CodeSystem.property.code # CodeSystem.concept.property.value[x] : 1..1 Value of the property for this concept. One of these 7 fhir:CodeSystem.concept.property.valueCode [ code ] fhir:CodeSystem.concept.property.valueCoding [ Coding ] fhir:CodeSystem.concept.property.valueString [ string ] fhir:CodeSystem.concept.property.valueInteger [ integer ] fhir:CodeSystem.concept.property.valueBoolean [ boolean ] fhir:CodeSystem.concept.property.valueDateTime [ dateTime ] fhir:CodeSystem.concept.property.valueDecimal [ decimal ] ], ...; fhir:CodeSystem.concept.concept [ See CodeSystem.concept ], ... ; # 0..* Child Concepts (is-a/contains/categorizes) ], ...; ]
Changes since Release 3
CodeSystem | |
|
|
CodeSystem.hierarchyMeaning |
|
CodeSystem.content |
|
CodeSystem.filter.operator |
|
CodeSystem.property.type |
|
See the Full Difference for further information
This analysis is available as XML or JSON .
See R3 <--> R4 Conversion Maps (status = 4 tests that all execute ok. All tests pass round-trip testing and 3 r3 resources are invalid (0 errors). )
See
the
Profiles
&
Extensions
and
the
alternate
definitions:
Master
Definition
XML
+
JSON
,
XML
Schema
/
Schematron
+
JSON
Schema
,
ShEx
(for
Turtle
)
+
see
,
the
extensions
spreadsheet
version
&
the
dependency
analysis
a
Path | Definition | Type | Reference |
---|---|---|---|
CodeSystem.status |
| Required | PublicationStatus |
CodeSystem.jurisdiction |
| Extensible | Jurisdiction ValueSet |
CodeSystem.hierarchyMeaning |
| Required | CodeSystemHierarchyMeaning |
CodeSystem.content |
| Required | CodeSystemContentMode |
CodeSystem.filter.operator |
| Required | FilterOperator |
CodeSystem.property.type |
| Required | PropertyType |
CodeSystem.concept.designation.language | A human language. | Preferred , but limited to AllLanguages | CommonLanguages |
CodeSystem.concept.designation.use |
| Extensible | DesignationUse |
id | Level | Location | Description | Expression |
| Warning | (base) | Name should be usable as an identifier for the module by machine processing applications such as code generation | name.matches('[A-Z]([A-Za-z0-9_]){0,254}') |
csd-1 | Rule | (base) | Within a code system definition, all the codes SHALL be unique | concept.code.combine($this.descendants().concept.code).isDistinct() |
Most code systems evolve over time, due to corrections, clarifications, and changes to approach or underlying knowledge or reality. If these changes lead to the meanings of existing codes changing significantly, then the interpretation of the code system becomes version dependent. This significantly complicates implementation based on the code system, to the point where it is not clear that safety can be assured, so changing the meaning of an existing code SHOULD be avoided whenever possible. It is preferable to assign a new identifier to a code system when any concepts in it have a significant change in meaning (for example, the German diagnostic classification code system ICD10GM2009 has a different system to ICD10GM2008), but this also can have substantial impact on implementation, so is often not practical - for instance, SNOMED CT has a complex version release framework, which may lead to variations in meaning of concepts, but there is only one identifier for SNOMED CT.
For
this
reason,
a
code
system
MAY
provide
a
version
identifier
which
can
be
specified
in
CodeSystem.version
.
The
version
specific
identifier
SHOULD
be
provided
whenever
there
are
potentially
significant
changes
in
meaning
across
multiple
releases
of
a
code
system.
There
is
no
particular
format
requirement
for
the
version
identifier,
though
HL7
recommends
a
date-based
approach.
When
the
CodeSystem.versionNeeded
is
'true',
then
the
version
identifier
SHALL
be
used
in
Coding
instances
that
refer
to
the
code
system.
Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use as the version string the date (expressed in FHIR date format) on which the version of the code system that is being used was officially published.
The
simple
case
for
a
code
system
is
that
the
entire
code
system
-
all
the
concepts
and
their
codes,
designations
and
properties
are
distributed
in
a
single
CodeSystem
resource.
However,
for
a
variety
of
reasons,
code
systems
may
be
distributed
by
the
code
system
authority
in
a
set
of
fragments,
and
other
authorities
may
issue
additional
designations
and
properties
in
supplements.
If
the
CodeSystem.content
value
is
fragment
,
then
the
resource
describes
part
of
a
code
system.
Code Systems may be distributed in fragments for the following reasons:
The following rules apply to code system fragments:
If
the
CodeSystem.content
value
is
supplement
,
then
the
resource
describes
a
code
system
supplement.
The
following
rules
apply
to
code
system
supplements:
CodeSystem.supplements
element
SHALL
have
a
value,
which
is
the
URL
of
the
code
system
being
supplemented
CodeSystem.url
for
a
supplement
SHALL
never
appear
in
a
Coding.system
CodeSystem.url
for
a
supplement
must
be
under
the
control
of
the
authority
creating
or
publishing
the
supplement
(e.g.
not
in
the
same
space
as
the
code
system
being
supplemented,
unless
the
supplement
is
being
issued
by
the
same
authority
as
the
original
code
system
If
a
supplement
needs
to
define
new
concepts/codes
to
use
as
property
values,
it
can
be
paired
with
a
new
(possibly
contained)
Code
System
and
use
the
Coding
type
for
the
property
values.
The impact of Code System supplements on value set expansion - and therefore value set validation - is subject to ongoing experimentation and implementation testing, and further clarification and additional rules might be proposed in future versions of this specification.
Concepts
have
both
a
display
and
a
definition
.
The
display
is
a
short
text
that
represents
the
meaning
of
the
concept
to
human
users,
while
the
definition
is
a
more
formal
statement
of
the
meaning
of
the
concept,
which
is
often
longer.
All
concepts
SHOULD
have
a
display
and
a
definition
,
though
it
is
not
mandatory
because
there
are
many
cases
where
no
such
properties
are
provided,
in
spite
of
their
utility
and
importance
for
clear
and
safe
communication.
In
addition
to
the
display
and
definition,
a
concept
can
have
one
or
more
designation
elements.
The
display
is
equivalent
to
a
special
designation
with
an
implied
designation.use
meaning
"primary
code/designation"
and
a
language
equal
to
the
Resource
Language
.
The
designations
can
provide
additional
displays
for
other
language,
as
well
as
designations
for
other
purposes.
When
using
concepts,
applications
use
the
display
and
designation
unless
the
language
or
usage
in
context
provides
a
reason
to
use
one
of
the
designations.
Each code system can define one or more concept properties. Each concept defined by the code system may have one or more values for each concept property defined by the code system. Typical uses for properties include:
Properties
are
identified
by
their
master
URI
(
CodeSystem.property.uri
),
and
then,
by
their
code
(
CodeSystem.property.code
),
which
is
used
both
internally
within
the
code
system
resource
(
CodeSystem.concept.property.code
)
and
also
externally,
in
the
following
places:
ConceptMap.element.target.dependsOn.property
and
ConceptMap.element.target.product.property
ValueSet.compose.include.filter.property
can
refer
to
any
defined
code
system
property
Parameters.parameter.name
when
returning
information
about
a
code
Parameters.parameter.part.name
for
dependencies
and
products
Parameters.parameter.name
when
providing
codes,
and
in
Parameters.parameter.name
when
asking
for
codes
Properties are defined using the following elements:
Name | Details | Description |
code | code | Used to identify the property, in the places shown in the list immediately above this table |
uri | optional uri | Reference to the formal meaning of the property. One possible source of meaning is the Concept Properties code system. This part of the definition is optional, but is recommended to provide an additional level of definitional consistency |
description | optional string | A description of the property- why it is defined, and how its value might be used |
type | code | Coding | string | integer | boolean | dateTime | The type of the property value. Properties of type "code" contain a code defined by the code system (e.g. a reference to another defined concept) |
Note that properties provide a common view of concept relationships that is common across all code systems. Some code systems define properties with more sophistication, such as groups of properties, or subsumption relationships between properties (e.g. SNOMED CT). Servers providing support for these code systems will need to know full details about the underlying relationships in order to provide the correct information about concepts and their properties, but this information does not surface in the resources or operations defined by the FHIR specification.
Many Code Systems have a 'status' associated with the concept. This may categorize the concept as:
There is wide variation in the life cycles supported by the different code systems, the words they use to describe the various status values they use, and some code systems have additional status values. HL7 uses Active and Retired. In addition to these status codes, concepts may also be labeled as "Abstract' (not to be used in some circumstances), and have dates associated with their retirement or deprecation. All this information is represented as properties of the concepts. In order to assist with consistency between code systems, the following basic property URIs are defined:
http://hl7.org/fhir/concept-properties#status : code |
A
property
that
indicates
the
status
of
the
concept.
If
the
property
is
identified
by
this
URL,
then
it
SHALL
use
at
least
these
status
values
(where
appropriate):
|
http://hl7.org/fhir/concept-properties#retirementDate : date | Date Concept was retired |
http://hl7.org/fhir/concept-properties#deprecationDate : date | Date Concept was deprecated |
http://hl7.org/fhir/concept-properties#parent : code | An immediate parent of the concept in the hierarchy |
http://hl7.org/fhir/concept-properties#child : code | An immediate child of the concept in the hierarchy |
http://hl7.org/fhir/concept-properties#notSelectable : boolean | This concept is a grouping concept and not intended to be used in the normal use of the code system (though may be used for filters etc.). This is also known as 'Abstract' |
The parent and child properties are used when performing concept lookup (using the $lookup operation), and when using properties to indicate parent/child relationships (see below).
Code
systems
may
be
presented
hierarchically,
using
nested
concept
elements,
where
the
hierarchy
has
a
defined
meaning
specified
in
hierarchyMeaning
.
The
code
system
hierarchy
is
a
single
tree,
where
concepts
have
only
one
parent.
Some code systems define concepts that have multiple parents. If a code system has concepts like this (typically, concepts that are subsumed by more than one other concept), the code system SHOULD NOT be represented using the hierarchy structure in the Code System resource, and the relationships between concepts should be defined using properties . If the hierarchy is used, implementers SHALL use a property to indicate additional parents that are not represented in the structural (nested concepts) hierarchy.
Operations based on the codeSystem resource SHALL have the same result whether or not the relationships are represented explicitly as properties or implicitly using the CodeSystem resource hierarchy.
The words 'subsume', 'subsumes', 'subsumed' and 'subsumption' are defined in relation to the type of hierarchy (i.e. the value of CodeSystem.hierarchyMeaning ) identified for the code system that is being represented by the CodeSystem resource. Concept A is considered to be subsumed by Concept B if it comes under Concept B in the hierarchy, or if a parent/child relationship is declared in the properties, and the hierarchyMeaning is "is-a").
Where a CodeSystem does not declare its hierarchy meaning directly, then the code system documentation must be consulted manually to determine how subsumption is determined. If there is no definition, none of the subsumption based features can be used with the code system.
Subsumption based logic arises explicitly or implicitly in the following places in the FHIR specification:
The following filters are defined for all code systems:
Property Name | Operation | Value | Definition | Notes |
---|---|---|---|---|
[property] | = | [string] | Includes all codes that have a property value equal to the specified string, where [property] is the code for any defined property | |
[property] | in | [string,string...] | Includes all codes that have a property value equal to one of the specified strings, where [property] is the code for any defined property | The values cannot include ",", since it is being used as a delimiter |
This draft section about the relationships between rich terminologies and structured content is still undergoing review.
Some other parts of the FHIR infrastructure define set of concepts that may also be treated as code systems. This is most useful when mapping between systems using Concept Maps , but might also be useful for other code system related functionality (e.g. subsetting use Value Sets ). This table summarizes how to treat these items as a terminology:
StructureDefinition |
The
StructureDefinition.url
(canonical
URL)
is
the
system
.
Each
.snapshot.element.id
in
the
snapshot
is
a
code
in
the
code
system
|
Questionnaire |
The
Questionnaire.url
(canonical
URL)
is
the
system
.
Each
.item.linkId
in
the
snapshot
is
a
code
in
the
code
system.
Items
with
no
linkId
cannot
be
addressed
|
Medication | Medication resources are a bit different, since they don't have a canonical URL, and there are not multiple items in a resource. So to refer to a medication resource, the system is [base]/Medication, where base is the server address. The Logical Id of the resource is the code |
The use of these implicit code systems is not yet well tested, so this section remains informative.
For medications, the relationship between the code system and the medication resource is complex. Many medication related code systems (e.g. RxNorm, DM+D, AMT, etc.) represent more complex information than just code, display name and code system. These often contain information about the content of the medication A similar principle applies to observation definitions, which overlap significantly with LOINC and other related code systems, which contain a set of observation definitions, that contain methods, units, etc. Other similar arrangements exist for Location and many other kinds of resource.
In
FHIR,
these
are
handled
by
splitting
the
concept
into
two
distinct
parts
-
the
Terminology,
(
Code
System
&
ValueSet
resources)
is
used
to
manage
the
codes,
display
names
and
relationships.
A
separate
"detail"
resource
(e.g.,
Medication
resource
instances
for
RxNorm
code
details,
ObservationDefinition
instances
for
LOINC
code
details,
or
Location
,
etc.)
is
used
to
convey
detailed
information
(dose
form
&
strength,
allowed
data
type
or
permitted
values,
address
&
hours
of
operation,
etc.).
One
"detail"
resource
instance
is
created
for
each
code.
This division accomplishes several things:
CodeSystem
/
ValueSet
.
Note that this division in FHIR does not imply that a similar division is required in the internal representation used by systems exposing a FHIR interface. Similarly, some systems may choose to only expose or maintain one aspect of such information types (i.e. only the discrete resource instances or only the value set).
The
linkage
between
the
"detail"
resource
and
the
Terminology
resources
is
accomplished
via
the
code
element
(or
equivalent)
on
the
detail
resource.
As
well,
the
"name"
or
"title"
on
the
detail
resource
generally
corresponds
with
the
display
name
on
the
matching
code.
Most
detail
resources
will
also
have
an
"identifier"
element.
This
can
be
set
to
the
same
value
and
namespace
as
the
code,
but
if
the
only
identifier
a
resource
has
is
its
defining
code,
it
may
be
better
to
omit
the
identifier
entirely.
.
Search parameters for this resource. The common parameters also apply. See Searching for more information about searching in REST, messaging, and services.
Name | Type | Description | Expression | In Common |
code
| token | A code defined in the code system | CodeSystem.concept.code | |
content-mode
| token | not-present | example | fragment | complete | supplement | CodeSystem.content | |
context TU | token | A use context assigned to the code system | (CodeSystem.useContext.value as CodeableConcept) | |
context-quantity TU | quantity | A quantity- or range-valued use context assigned to the code system | (CodeSystem.useContext.value as Quantity) | (CodeSystem.useContext.value as Range) | |
context-type TU | token | A type of use context assigned to the code system | CodeSystem.useContext.code | |
context-type-quantity TU | composite | A use context type and quantity- or range-based value assigned to the code system |
On
CodeSystem.useContext:
context-type: code context-quantity: value.as(Quantity) | value.as(Range) | |
context-type-value TU | composite | A use context type and value assigned to the code system |
On
CodeSystem.useContext:
context-type: code context: value.as(CodeableConcept) | |
date
| date | The code system publication date | CodeSystem.date | |
description
| string | The description of the code system | CodeSystem.description | |
identifier TU | token | External identifier for the code system | CodeSystem.identifier | |
jurisdiction TU | token | Intended jurisdiction for the code system | CodeSystem.jurisdiction | |
language
| token | A language in which a designation is provided | CodeSystem.concept.designation.language | |
name
| string | Computationally friendly name of the code system | CodeSystem.name | |
publisher
| string | Name of the publisher of the code system | CodeSystem.publisher | |
status
| token | The current status of the code system | CodeSystem.status | |
supplements
| reference | Find code system supplements for the referenced code system |
CodeSystem.supplements
( CodeSystem ) | |
system
| uri | The system for any codes defined by this code system (same as 'url') | CodeSystem.url | |
title
| string | The human-friendly name of the code system | CodeSystem.title | |
url
| uri | The uri that identifies the code system | CodeSystem.url | |
version
| token | The business version of the code system | CodeSystem.version |