Extension-valueset-reference

This extension allows the referencing of codes to a specific valueset. Within this implementation guide it is used to differentiate the SNOMED CT refsets in the UKCore-Observation-Lab.code element slicing.

Tree View

id0..1string
extensionC0..0Extension
url1..1uriFixed Value
valueUriuri

Table View

Extension0..1
Extension.idstring0..1
Extension.extensionExtension0..0
Extension.urluri1..1
Extension.value[x]uri1..1

XML View

<StructureDefinition xmlns="http://hl7.org/fhir">
<id value="valueset-reference" />
<extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-wg">
<valueCode value="vocab" />
</extension>
<extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm">
<valueInteger value="1" />
</extension>
<url value="http://hl7.org/fhir/StructureDefinition/valueset-reference" />
<version value="4.0.1" />
<name value="reference" />
<status value="draft" />
<date value="2019-11-01T09:29:23+11:00" />
<publisher value="HL7" />
<description value="A logical reference (e.g. a reference to ValueSet.url) that identifies the value set/version that identifies the set of possible coded values this coding was chosen from or constrained by." />
<fhirVersion value="4.0.1" />
<mapping>
<identity value="v2" />
<uri value="http://hl7.org/v2" />
<name value="HL7 v2 Mapping" />
</mapping>
<mapping>
<identity value="rim" />
<uri value="http://hl7.org/v3" />
<name value="RIM Mapping" />
</mapping>
<kind value="complex-type" />
<abstract value="false" />
<context>
<type value="element" />
<expression value="Coding" />
</context>
<type value="Extension" />
<baseDefinition value="http://hl7.org/fhir/StructureDefinition/Extension" />
<derivation value="constraint" />
<snapshot>
<element id="Extension">
<path value="Extension" />
<short value="Url of Value set the code was chosen from" />
<definition value="A logical reference (e.g. a reference to ValueSet.url) that identifies the value set/version that identifies the set of possible coded values this coding was chosen from or constrained by." />
<comment value="If this extension is used with an [extensible binding](terminologies.html#extensible), and the concept comes from outside the bound valueset, the value set SHALL be different from the bound valueset." />
<min value="0" />
<max value="1" />
<base>
<path value="Extension" />
<min value="0" />
<max value="*" />
</base>
<condition value="ele-1" />
<constraint>
<key value="ele-1" />
<severity value="error" />
<human value="All FHIR elements must have a @value or children" />
<expression value="hasValue() or (children().count() > id.count())" />
<xpath value="@value|f:*|h:div" />
<source value="http://hl7.org/fhir/StructureDefinition/Element" />
</constraint>
<constraint>
<key value="ext-1" />
<severity value="error" />
<human value="Must have either extensions or value[x], not both" />
<expression value="extension.exists() != value.exists()" />
<xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), 'value')])" />
<source value="http://hl7.org/fhir/StructureDefinition/Extension" />
</constraint>
<isModifier value="false" />
<mapping>
<identity value="v2" />
<map value="CWE." />
</mapping>
<mapping>
<identity value="rim" />
<map value="CD.valueSet/CD.valueSetVersion" />
</mapping>
</element>
<element id="Extension.id">
<path value="Extension.id" />
<representation value="xmlAttr" />
<short value="Unique id for inter-element referencing" />
<definition value="Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces." />
<min value="0" />
<max value="1" />
<base>
<path value="Element.id" />
<min value="0" />
<max value="1" />
</base>
<type>
<extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
<valueUrl value="string" />
</extension>
<code value="http://hl7.org/fhirpath/System.String" />
</type>
<isModifier value="false" />
<isSummary value="false" />
<mapping>
<identity value="rim" />
<map value="n/a" />
</mapping>
</element>
<element id="Extension.extension">
<path value="Extension.extension" />
<slicing>
<discriminator>
<type value="value" />
<path value="url" />
</discriminator>
<description value="Extensions are always sliced by (at least) url" />
<rules value="open" />
</slicing>
<short value="Extension" />
<definition value="An Extension" />
<min value="0" />
<max value="0" />
<base>
<path value="Element.extension" />
<min value="0" />
<max value="*" />
</base>
<type>
<code value="Extension" />
</type>
<constraint>
<key value="ele-1" />
<severity value="error" />
<human value="All FHIR elements must have a @value or children" />
<expression value="hasValue() or (children().count() > id.count())" />
<xpath value="@value|f:*|h:div" />
<source value="http://hl7.org/fhir/StructureDefinition/Element" />
</constraint>
<constraint>
<key value="ext-1" />
<severity value="error" />
<human value="Must have either extensions or value[x], not both" />
<expression value="extension.exists() != value.exists()" />
<xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), "value")])" />
<source value="http://hl7.org/fhir/StructureDefinition/Extension" />
</constraint>
<isModifier value="false" />
<isSummary value="false" />
</element>
<element id="Extension.url">
<path value="Extension.url" />
<representation value="xmlAttr" />
<short value="identifies the meaning of the extension" />
<definition value="Source of the definition for the extension code - a logical name or a URL." />
<comment value="The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension." />
<min value="1" />
<max value="1" />
<base>
<path value="Extension.url" />
<min value="1" />
<max value="1" />
</base>
<type>
<extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
<valueUrl value="uri" />
</extension>
<code value="http://hl7.org/fhirpath/System.String" />
</type>
<fixedUri value="http://hl7.org/fhir/StructureDefinition/valueset-reference" />
<isModifier value="false" />
<isSummary value="false" />
<mapping>
<identity value="rim" />
<map value="N/A" />
</mapping>
</element>
<element id="Extension.value[x]">
<path value="Extension.value[x]" />
<short value="Value of extension" />
<definition value="Value of extension - must be one of a constrained set of the data types (see [Extensibility](http://hl7.org/fhir/extensibility.html) for a list)." />
<min value="1" />
<max value="1" />
<base>
<path value="Extension.value[x]" />
<min value="0" />
<max value="1" />
</base>
<type>
<code value="uri" />
</type>
<constraint>
<key value="ele-1" />
<severity value="error" />
<human value="All FHIR elements must have a @value or children" />
<expression value="hasValue() or (children().count() > id.count())" />
<xpath value="@value|f:*|h:div" />
<source value="http://hl7.org/fhir/StructureDefinition/Element" />
</constraint>
<isModifier value="false" />
<isSummary value="false" />
<mapping>
<identity value="rim" />
<map value="N/A" />
</mapping>
</element>
</snapshot>
<differential>
<element id="Extension">
<path value="Extension" />
<short value="Url of Value set the code was chosen from" />
<definition value="A logical reference (e.g. a reference to ValueSet.url) that identifies the value set/version that identifies the set of possible coded values this coding was chosen from or constrained by." />
<comment value="If this extension is used with an [extensible binding](terminologies.html#extensible), and the concept comes from outside the bound valueset, the value set SHALL be different from the bound valueset." />
<min value="0" />
<max value="1" />
<isModifier value="false" />
<mapping>
<identity value="v2" />
<map value="CWE." />
</mapping>
<mapping>
<identity value="rim" />
<map value="CD.valueSet/CD.valueSetVersion" />
</mapping>
</element>
<element id="Extension.extension">
<path value="Extension.extension" />
<max value="0" />
</element>
<element id="Extension.url">
<path value="Extension.url" />
<fixedUri value="http://hl7.org/fhir/StructureDefinition/valueset-reference" />
</element>
<element id="Extension.value[x]">
<path value="Extension.value[x]" />
<min value="1" />
<type>
<code value="uri" />
</type>
</element>
</differential>
</StructureDefinition>

JSON View

{
"resourceType": "StructureDefinition",
"id": "valueset-reference",
"extension": [
{
"url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-wg",
"valueCode": "vocab"
},
{
"url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm",
"valueInteger": 1
}
],
"url": "http://hl7.org/fhir/StructureDefinition/valueset-reference",
"version": "4.0.1",
"name": "reference",
"status": "draft",
"date": "2019-11-01T09:29:23+11:00",
"publisher": "HL7",
"description": "A logical reference (e.g. a reference to ValueSet.url) that identifies the value set/version that identifies the set of possible coded values this coding was chosen from or constrained by.",
"fhirVersion": "4.0.1",
"mapping": [
{
"identity": "v2",
"uri": "http://hl7.org/v2",
"name": "HL7 v2 Mapping"
},
{
"identity": "rim",
"uri": "http://hl7.org/v3",
"name": "RIM Mapping"
}
],
"kind": "complex-type",
"abstract": false,
"context": [
{
"type": "element",
"expression": "Coding"
}
],
"type": "Extension",
"baseDefinition": "http://hl7.org/fhir/StructureDefinition/Extension",
"derivation": "constraint",
"snapshot": {
"element": [
{
"id": "Extension",
"path": "Extension",
"short": "Url of Value set the code was chosen from",
"definition": "A logical reference (e.g. a reference to ValueSet.url) that identifies the value set/version that identifies the set of possible coded values this coding was chosen from or constrained by.",
"comment": "If this extension is used with an [extensible binding](terminologies.html#extensible), and the concept comes from outside the bound valueset, the value set SHALL be different from the bound valueset.",
"min": 0,
"max": "1",
"base": {
"path": "Extension",
"min": 0,
"max": "*"
},
"condition": [
"ele-1"
],
"constraint": [
{
"key": "ele-1",
"severity": "error",
"human": "All FHIR elements must have a @value or children",
"expression": "hasValue() or (children().count() > id.count())",
"xpath": "@value|f:*|h:div",
"source": "http://hl7.org/fhir/StructureDefinition/Element"
},
{
"key": "ext-1",
"severity": "error",
"human": "Must have either extensions or value[x], not both",
"expression": "extension.exists() != value.exists()",
"xpath": "exists(f:extension)!=exists(f:*[starts-with(local-name(.), 'value')])",
"source": "http://hl7.org/fhir/StructureDefinition/Extension"
}
],
"isModifier": false,
"mapping": [
{
"identity": "v2",
"map": "CWE."
},
{
"identity": "rim",
"map": "CD.valueSet/CD.valueSetVersion"
}
]
},
{
"id": "Extension.id",
"path": "Extension.id",
"representation": [
"xmlAttr"
],
"short": "Unique id for inter-element referencing",
"definition": "Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.",
"min": 0,
"max": "1",
"base": {
"path": "Element.id",
"min": 0,
"max": "1"
},
"type": [
{
"extension": [
{
"url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
"valueUrl": "string"
}
],
"code": "http://hl7.org/fhirpath/System.String"
}
],
"isModifier": false,
"isSummary": false,
"mapping": [
{
"identity": "rim",
"map": "n/a"
}
]
},
{
"id": "Extension.extension",
"path": "Extension.extension",
"slicing": {
"discriminator": [
{
"type": "value",
"path": "url"
}
],
"description": "Extensions are always sliced by (at least) url",
"rules": "open"
},
"short": "Extension",
"definition": "An Extension",
"min": 0,
"max": "0",
"base": {
"path": "Element.extension",
"min": 0,
"max": "*"
},
"type": [
{
"code": "Extension"
}
],
"constraint": [
{
"key": "ele-1",
"severity": "error",
"human": "All FHIR elements must have a @value or children",
"expression": "hasValue() or (children().count() > id.count())",
"xpath": "@value|f:*|h:div",
"source": "http://hl7.org/fhir/StructureDefinition/Element"
},
{
"key": "ext-1",
"severity": "error",
"human": "Must have either extensions or value[x], not both",
"expression": "extension.exists() != value.exists()",
"xpath": "exists(f:extension)!=exists(f:*[starts-with(local-name(.), \"value\")])",
"source": "http://hl7.org/fhir/StructureDefinition/Extension"
}
],
"isModifier": false,
"isSummary": false
},
{
"id": "Extension.url",
"path": "Extension.url",
"representation": [
"xmlAttr"
],
"short": "identifies the meaning of the extension",
"definition": "Source of the definition for the extension code - a logical name or a URL.",
"comment": "The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.",
"min": 1,
"max": "1",
"base": {
"path": "Extension.url",
"min": 1,
"max": "1"
},
"type": [
{
"extension": [
{
"url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
"valueUrl": "uri"
}
],
"code": "http://hl7.org/fhirpath/System.String"
}
],
"fixedUri": "http://hl7.org/fhir/StructureDefinition/valueset-reference",
"isModifier": false,
"isSummary": false,
"mapping": [
{
"identity": "rim",
"map": "N/A"
}
]
},
{
"id": "Extension.value[x]",
"path": "Extension.value[x]",
"short": "Value of extension",
"definition": "Value of extension - must be one of a constrained set of the data types (see [Extensibility](http://hl7.org/fhir/extensibility.html) for a list).",
"min": 1,
"max": "1",
"base": {
"path": "Extension.value[x]",
"min": 0,
"max": "1"
},
"type": [
{
"code": "uri"
}
],
"constraint": [
{
"key": "ele-1",
"severity": "error",
"human": "All FHIR elements must have a @value or children",
"expression": "hasValue() or (children().count() > id.count())",
"xpath": "@value|f:*|h:div",
"source": "http://hl7.org/fhir/StructureDefinition/Element"
}
],
"isModifier": false,
"isSummary": false,
"mapping": [
{
"identity": "rim",
"map": "N/A"
}
]
}
]
},
"differential": {
"element": [
{
"id": "Extension",
"path": "Extension",
"short": "Url of Value set the code was chosen from",
"definition": "A logical reference (e.g. a reference to ValueSet.url) that identifies the value set/version that identifies the set of possible coded values this coding was chosen from or constrained by.",
"comment": "If this extension is used with an [extensible binding](terminologies.html#extensible), and the concept comes from outside the bound valueset, the value set SHALL be different from the bound valueset.",
"min": 0,
"max": "1",
"isModifier": false,
"mapping": [
{
"identity": "v2",
"map": "CWE."
},
{
"identity": "rim",
"map": "CD.valueSet/CD.valueSetVersion"
}
]
},
{
"id": "Extension.extension",
"path": "Extension.extension",
"max": "0"
},
{
"id": "Extension.url",
"path": "Extension.url",
"fixedUri": "http://hl7.org/fhir/StructureDefinition/valueset-reference"
},
{
"id": "Extension.value[x]",
"path": "Extension.value[x]",
"min": 1,
"type": [
{
"code": "uri"
}
]
}
]
}
}

Example Usage

The following shows the code 1000821000000103 | Serum albumin level | which is from the SNOMED CT PBCL Observables reference set. This code is equivalent to 1105861000000106 | Albumin mass concentration in serum | from the SNOMED CT PaLM Observables reference set.

"code": {
    "coding": [
        {
        "extension": [
            {
            "url": "http://hl7.org/fhir/StructureDefinition/valueset-reference",
            "valueUri": "https://fhir.hl7.org.uk/ValueSet/UKCore-PathologyBoundedCodeListObservables"
            }
        ],
        "system": "http://snomed.info/sct",
        "code": "1000821000000103",
        "display": "Serum albumin level"
        },
        {
        "extension": [
            {
            "url": "http://hl7.org/fhir/StructureDefinition/valueset-reference",
            "valueUri": "https://fhir.hl7.org.uk/ValueSet/UKCore-PathologyAndLaboratoryMedicineObservables"
            }
        ],
        "system": "http://snomed.info/sct",
        "code": "1105861000000106",
        "display": "Albumin mass concentration in serum"
        }
        ]
    }


<code>
    <coding>
        <extension url="http://hl7.org/fhir/StructureDefinition/valueset-reference">
            <valueUri value="https://fhir.hl7.org.uk/ValueSet/UKCore-PathologyBoundedCodeListObservables" />
        </extension>
        <system value="http://snomed.info/sct" />
        <code value="1000821000000103" />
        <display value="Serum albumin level" />
    </coding>
    <coding>
        <extension url="http://hl7.org/fhir/StructureDefinition/valueset-reference">
            <valueUri value="https://fhir.hl7.org.uk/ValueSet/UKCore-PathologyAndLaboratoryMedicineObservables" />
        </extension>
        <system value="http://snomed.info/sct" />
        <code value="1105861000000106" />
        <display value="Albumin mass concentration in serum" />
    </coding>
</code>