ExtensionEvidence_UseContext - Definitions - Extensions for Using Data Elements from FHIR R5 in FHIR STU3 v0.1.0

Extensions for Using Data Elements from FHIR R5 in FHIR STU3 - Downloaded Version null See the Directory of published versions

Extension: ExtensionEvidence_UseContext - Detailed Descriptions

Page standards status: Trial-use

Maturity Level: 0

Definitions for the ext-R5-Evidence.useContext extension.

Key Elements Table
Differential Elements Table
Snapshot Elements Table

Guidance on how to interpret the contents of this table can be foundhere

0. Extension
Definition	R5: `Evidence.useContext` (new:UsageContext) Optional Extension Element - found in all resources.
Short	R5: The context that the content is intended to support (new)Optional Extensions Element
Comments	Element `Evidence.useContext` is not mapped to FHIR STU3, since FHIR R5 `Evidence` is not mapped. Element `Evidence.useContext` has no mapping targets in FHIR STU3. Typically, this is because the element has been added (is a new element). When multiple useContexts are specified, there is no expectation that all or any of the contexts apply.
Control	0..* This element is affected by the following invariants: ele-1
Is Modifier	false
Invariants	ele-1: All FHIR elements must have a @value or children (`hasValue() \| (children().count() > id.count())`) ext-1: Must have either extensions or value[x], not both (`extension.exists() != value.exists()`) ele-1: All FHIR elements must have a @value or children (hasValue() \| (children().count() > id.count())) ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
2. Extension.extension
Definition	An Extension May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.
Short	ExtensionAdditional Content defined by implementations
Comments	There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.
Control	0..*
Type	Extension
Alternate Names	extensions, user content
Slicing	This element introduces a set of slices on `Extension.extension`. The slices areUnordered and Open, and can be differentiated using the following discriminators: value @ url
4. Extension.extension:_datatype
Slice Name	_datatype
Definition	Slice to indicate the presence of a R5 `UsageContext` in FHIR STU3
Short	DataType slice for a FHIR R5 `UsageContext` valueAdditional Content defined by implementations
Control	10..1*
Type	Extension
6. Extension.extension:_datatype.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Short	identifies the meaning of the extension
Comments	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.
Control	1..1
Type	uri
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
XML Format	In the XML format, this property is represented as an attribute.
Fixed Value	`http://hl7.org/fhir/StructureDefinition/_datatype`
8. Extension.extension:_datatype.value[x]
Definition	Value of extension - may be a resource or one of a constrained set of the data types (see Extensibility in the spec for list).
Short	Value of extension
Comments	Must be: UsageContext
Control	10..1
Type	string, date, dateTime, Meta, code, Address, Attachment, integer, oid, Count, instant, ContactPoint, HumanName, Money, Identifier, Coding, markdown, SampledData, Ratio, id, positiveInt, Age, Distance, Reference, Period, Quantity, Duration, Range, uri, Annotation, boolean, base64Binary, Signature, unsignedInt, time, Timing, decimal, CodeableConcept
[x] Note	SeeChoice of Data Typesfor further information about how to use [x]
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
Fixed Value	`UsageContext`
10. Extension.extension:code
Slice Name	code
Definition	R5: `UsageContext.code`
Short	R5: codeAdditional Content defined by implementations
Comments	Element `UsageContext.code` is mapped to FHIR STU3 element `UsageContext.code` as `Equivalent`.
Control	10..1*
Type	Extension
Requirements	Element `UsageContext.code` is mapped to FHIR STU3 element `UsageContext.code` as `Equivalent`.
12. Extension.extension:code.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Short	identifies the meaning of the extension
Comments	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.
Control	1..1
Type	uri
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
XML Format	In the XML format, this property is represented as an attribute.
Fixed Value	`code`
14. Extension.extension:code.value[x]
Definition	A code that identifies the type of context being specified by this usage context. Value of extension - may be a resource or one of a constrained set of the data types (see Extensibility in the spec for list).
Short	Type of context being specifiedValue of extension
Control	10..1
Binding	Unless not suitable, these codes SHALL be taken from For codes, see UsageContextType (extensible to `http://hl7.org/fhir/ValueSet/usage-context-type\|3.0.2`) A code that specifies a type of context being specified by a usage context.
Type	Coding, date, dateTime, Meta, code, string, Address, Attachment, integer, oid, Count, instant, ContactPoint, HumanName, Money, Identifier, markdown, SampledData, Ratio, id, positiveInt, Age, Distance, Reference, Period, Quantity, Duration, Range, uri, Annotation, boolean, base64Binary, Signature, unsignedInt, time, Timing, decimal, CodeableConcept
[x] Note	SeeChoice of Data Typesfor further information about how to use [x]
16. Extension.extension:value
Slice Name	value
Definition	R5: `UsageContext.value[x]` additional types (Reference(http://hl7.org/fhir/StructureDefinition/PlanDefinition), Reference(http://hl7.org/fhir/StructureDefinition/ResearchStudy), Reference(http://hl7.org/fhir/StructureDefinition/InsurancePlan), Reference(http://hl7.org/fhir/StructureDefinition/HealthcareService), Reference(http://hl7.org/fhir/StructureDefinition/Group), Reference(http://hl7.org/fhir/StructureDefinition/Location), Reference(http://hl7.org/fhir/StructureDefinition/Organization))
Short	R5: value additional typesAdditional Content defined by implementations
Comments	Element `UsageContext.value[x]` is mapped to FHIR STU3 element `UsageContext.value[x]` as `SourceIsBroaderThanTarget`. The mappings for `UsageContext.value[x]` do not cover the following types: Reference. The target context `UsageContext.value[x]` is a choice-type element and cannot directly hold extensions. The context is moved up to parent element `UsageContext`.
Control	10..1*
Type	Extension
Requirements	Element `UsageContext.value[x]` is mapped to FHIR STU3 element `UsageContext.value[x]` as `SourceIsBroaderThanTarget`. The mappings for `UsageContext.value[x]` do not cover the following types: Reference. The target context `UsageContext.value[x]` is a choice-type element and cannot directly hold extensions. The context is moved up to parent element `UsageContext`.
18. Extension.extension:value.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Short	identifies the meaning of the extension
Comments	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.
Control	1..1
Type	uri
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
XML Format	In the XML format, this property is represented as an attribute.
Fixed Value	`value`
20. Extension.extension:value.value[x]
Definition	A value that defines the context specified in this context of use. The interpretation of the value is defined by the code. Value of extension - may be a resource or one of a constrained set of the data types (see Extensibility in the spec for list).
Short	Value that defines the contextValue of extension
Control	10..1
Type	Reference(Cross-version Profile for R5.PlanDefinition for use in FHIR STU3, PlanDefinition, Cross-version Profile for R5.ResearchStudy for use in FHIR STU3, ResearchStudy, Cross-version Profile for R5.InsurancePlan for use in FHIR STU3, Basic, Cross-version Profile for R5.HealthcareService for use in FHIR STU3, HealthcareService, Cross-version Profile for R5.Group for use in FHIR STU3, Group, Cross-version Profile for R5.Location for use in FHIR STU3, Location, Cross-version Profile for R5.Organization for use in FHIR STU3, Organization), date, dateTime, Meta, code, string, Address, Attachment, integer, oid, Count, instant, ContactPoint, HumanName, Money, Identifier, Coding, markdown, SampledData, Ratio, id, positiveInt, Age, Distance, Period, Quantity, Duration, Range, uri, Annotation, boolean, base64Binary, Signature, unsignedInt, time, Timing, decimal, CodeableConcept
[x] Note	SeeChoice of Data Typesfor further information about how to use [x]
22. Extension.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Short	identifies the meaning of the extension
Comments	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.
Control	1..1
Type	uri
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
XML Format	In the XML format, this property is represented as an attribute.
Fixed Value	`http://hl7.org/fhir/5.0/StructureDefinition/extension-Evidence.useContext`
24. Extension.value[x]
Definition	Value of extension - may be a resource or one of a constrained set of the data types (see Extensibility in the spec for list).
Short	Value of extension
Control	0..01
Type	Choice of: base64Binary, boolean, code, date, dateTime, decimal, id, instant, integer, markdown, oid, positiveInt, string, time, unsignedInt, uri, Address, Age, Annotation, Attachment, CodeableConcept, Coding, ContactPoint, Count, Distance, Duration, HumanName, Identifier, Money, Period, Quantity, Range, Ratio, Reference, SampledData, Signature, Timing, Meta
Primitive Value	This primitive element may be present, or absent, or replaced by an extension

Guidance on how to interpret the contents of this table can be foundhere

0. Extension
Definition	R5: `Evidence.useContext` (new:UsageContext)
Short	R5: The context that the content is intended to support (new)
Comments	Element `Evidence.useContext` is not mapped to FHIR STU3, since FHIR R5 `Evidence` is not mapped. Element `Evidence.useContext` has no mapping targets in FHIR STU3. Typically, this is because the element has been added (is a new element). When multiple useContexts are specified, there is no expectation that all or any of the contexts apply.
Control	0..*
Is Modifier	false
2. Extension.extension
Control	0..*
Slicing	This element introduces a set of slices on `Extension.extension`. The slices areUnordered and Open, and can be differentiated using the following discriminators: value @ url
4. Extension.extension:_datatype
Slice Name	_datatype
Definition	Slice to indicate the presence of a R5 `UsageContext` in FHIR STU3
Short	DataType slice for a FHIR R5 `UsageContext` value
Control	1..1
6. Extension.extension:_datatype.url
Control	1..1
Fixed Value	`http://hl7.org/fhir/StructureDefinition/_datatype`
8. Extension.extension:_datatype.value[x]
Comments	Must be: UsageContext
Control	1..1
Type	string
[x] Note	SeeChoice of Data Typesfor further information about how to use [x]
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
Fixed Value	`UsageContext`
10. Extension.extension:code
Slice Name	code
Definition	R5: `UsageContext.code`
Short	R5: code
Comments	Element `UsageContext.code` is mapped to FHIR STU3 element `UsageContext.code` as `Equivalent`.
Control	1..1
Requirements	Element `UsageContext.code` is mapped to FHIR STU3 element `UsageContext.code` as `Equivalent`.
12. Extension.extension:code.url
Control	1..1
Fixed Value	`code`
14. Extension.extension:code.value[x]
Definition	A code that identifies the type of context being specified by this usage context.
Short	Type of context being specified
Control	1..1
Binding	Unless not suitable, these codes SHALL be taken from UsageContextType (extensible to `http://hl7.org/fhir/ValueSet/usage-context-type\|3.0.2`) A code that specifies a type of context being specified by a usage context.
Type	Coding
[x] Note	SeeChoice of Data Typesfor further information about how to use [x]
16. Extension.extension:value
Slice Name	value
Definition	R5: `UsageContext.value[x]` additional types (Reference(http://hl7.org/fhir/StructureDefinition/PlanDefinition), Reference(http://hl7.org/fhir/StructureDefinition/ResearchStudy), Reference(http://hl7.org/fhir/StructureDefinition/InsurancePlan), Reference(http://hl7.org/fhir/StructureDefinition/HealthcareService), Reference(http://hl7.org/fhir/StructureDefinition/Group), Reference(http://hl7.org/fhir/StructureDefinition/Location), Reference(http://hl7.org/fhir/StructureDefinition/Organization))
Short	R5: value additional types
Comments	Element `UsageContext.value[x]` is mapped to FHIR STU3 element `UsageContext.value[x]` as `SourceIsBroaderThanTarget`. The mappings for `UsageContext.value[x]` do not cover the following types: Reference. The target context `UsageContext.value[x]` is a choice-type element and cannot directly hold extensions. The context is moved up to parent element `UsageContext`.
Control	1..1
Requirements	Element `UsageContext.value[x]` is mapped to FHIR STU3 element `UsageContext.value[x]` as `SourceIsBroaderThanTarget`. The mappings for `UsageContext.value[x]` do not cover the following types: Reference. The target context `UsageContext.value[x]` is a choice-type element and cannot directly hold extensions. The context is moved up to parent element `UsageContext`.
18. Extension.extension:value.url
Control	1..1
Fixed Value	`value`
20. Extension.extension:value.value[x]
Definition	A value that defines the context specified in this context of use. The interpretation of the value is defined by the code.
Short	Value that defines the context
Control	1..1
Type	Reference(Cross-version Profile for R5.PlanDefinition for use in FHIR STU3, PlanDefinition, Cross-version Profile for R5.ResearchStudy for use in FHIR STU3, ResearchStudy, Cross-version Profile for R5.InsurancePlan for use in FHIR STU3, Basic, Cross-version Profile for R5.HealthcareService for use in FHIR STU3, HealthcareService, Cross-version Profile for R5.Group for use in FHIR STU3, Group, Cross-version Profile for R5.Location for use in FHIR STU3, Location, Cross-version Profile for R5.Organization for use in FHIR STU3, Organization)
[x] Note	SeeChoice of Data Typesfor further information about how to use [x]
22. Extension.url
Control	1..1
Fixed Value	`http://hl7.org/fhir/5.0/StructureDefinition/extension-Evidence.useContext`
24. Extension.value[x]
Control	0..0

Guidance on how to interpret the contents of this table can be foundhere

0. Extension
Definition	R5: `Evidence.useContext` (new:UsageContext)
Short	R5: The context that the content is intended to support (new)
Comments	Element `Evidence.useContext` is not mapped to FHIR STU3, since FHIR R5 `Evidence` is not mapped. Element `Evidence.useContext` has no mapping targets in FHIR STU3. Typically, this is because the element has been added (is a new element). When multiple useContexts are specified, there is no expectation that all or any of the contexts apply.
Control	0..* This element is affected by the following invariants: ele-1
Is Modifier	false
Invariants	ele-1: All FHIR elements must have a @value or children (`hasValue() \| (children().count() > id.count())`) ext-1: Must have either extensions or value[x], not both (`extension.exists() != value.exists()`)
2. Extension.id
Definition	unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
Short	xml:id (or equivalent in JSON)
Control	0..1
Type	string
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
XML Format	In the XML format, this property is represented as an attribute.
4. Extension.extension
Definition	An Extension
Short	Extension
Control	0..*
Type	Extension
Slicing	This element introduces a set of slices on `Extension.extension`. The slices areUnordered and Open, and can be differentiated using the following discriminators: value @ url
6. Extension.extension:_datatype
Slice Name	_datatype
Definition	Slice to indicate the presence of a R5 `UsageContext` in FHIR STU3
Short	DataType slice for a FHIR R5 `UsageContext` value
Control	1..1
Type	Extension
8. Extension.extension:_datatype.id
Definition	unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
Short	xml:id (or equivalent in JSON)
Control	0..1
Type	string
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
XML Format	In the XML format, this property is represented as an attribute.
10. Extension.extension:_datatype.extension
Definition	May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.
Short	Additional Content defined by implementations
Comments	There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.
Control	0..*
Type	Extension
Alternate Names	extensions, user content
Slicing	This element introduces a set of slices on `Extension.extension.extension`. The slices areUnordered and Open, and can be differentiated using the following discriminators: value @ url
12. Extension.extension:_datatype.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Short	identifies the meaning of the extension
Comments	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.
Control	1..1
Type	uri
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
XML Format	In the XML format, this property is represented as an attribute.
Fixed Value	`http://hl7.org/fhir/StructureDefinition/_datatype`
14. Extension.extension:_datatype.value[x]
Definition	Value of extension - may be a resource or one of a constrained set of the data types (see Extensibility in the spec for list).
Short	Value of extension
Comments	Must be: UsageContext
Control	1..1
Type	string
[x] Note	SeeChoice of Data Typesfor further information about how to use [x]
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
Fixed Value	`UsageContext`
16. Extension.extension:code
Slice Name	code
Definition	R5: `UsageContext.code`
Short	R5: code
Comments	Element `UsageContext.code` is mapped to FHIR STU3 element `UsageContext.code` as `Equivalent`.
Control	1..1
Type	Extension
Requirements	Element `UsageContext.code` is mapped to FHIR STU3 element `UsageContext.code` as `Equivalent`.
18. Extension.extension:code.id
Definition	unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
Short	xml:id (or equivalent in JSON)
Control	0..1
Type	string
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
XML Format	In the XML format, this property is represented as an attribute.
20. Extension.extension:code.extension
Definition	May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.
Short	Additional Content defined by implementations
Comments	There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.
Control	0..*
Type	Extension
Alternate Names	extensions, user content
Slicing	This element introduces a set of slices on `Extension.extension.extension`. The slices areUnordered and Open, and can be differentiated using the following discriminators: value @ url
22. Extension.extension:code.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Short	identifies the meaning of the extension
Comments	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.
Control	1..1
Type	uri
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
XML Format	In the XML format, this property is represented as an attribute.
Fixed Value	`code`
24. Extension.extension:code.value[x]
Definition	A code that identifies the type of context being specified by this usage context.
Short	Type of context being specified
Control	1..1
Binding	Unless not suitable, these codes SHALL be taken from UsageContextType (extensible to `http://hl7.org/fhir/ValueSet/usage-context-type\|3.0.2`) A code that specifies a type of context being specified by a usage context.
Type	Coding
[x] Note	SeeChoice of Data Typesfor further information about how to use [x]
26. Extension.extension:value
Slice Name	value
Definition	R5: `UsageContext.value[x]` additional types (Reference(http://hl7.org/fhir/StructureDefinition/PlanDefinition), Reference(http://hl7.org/fhir/StructureDefinition/ResearchStudy), Reference(http://hl7.org/fhir/StructureDefinition/InsurancePlan), Reference(http://hl7.org/fhir/StructureDefinition/HealthcareService), Reference(http://hl7.org/fhir/StructureDefinition/Group), Reference(http://hl7.org/fhir/StructureDefinition/Location), Reference(http://hl7.org/fhir/StructureDefinition/Organization))
Short	R5: value additional types
Comments	Element `UsageContext.value[x]` is mapped to FHIR STU3 element `UsageContext.value[x]` as `SourceIsBroaderThanTarget`. The mappings for `UsageContext.value[x]` do not cover the following types: Reference. The target context `UsageContext.value[x]` is a choice-type element and cannot directly hold extensions. The context is moved up to parent element `UsageContext`.
Control	1..1
Type	Extension
Requirements	Element `UsageContext.value[x]` is mapped to FHIR STU3 element `UsageContext.value[x]` as `SourceIsBroaderThanTarget`. The mappings for `UsageContext.value[x]` do not cover the following types: Reference. The target context `UsageContext.value[x]` is a choice-type element and cannot directly hold extensions. The context is moved up to parent element `UsageContext`.
28. Extension.extension:value.id
Definition	unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
Short	xml:id (or equivalent in JSON)
Control	0..1
Type	string
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
XML Format	In the XML format, this property is represented as an attribute.
30. Extension.extension:value.extension
Definition	May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.
Short	Additional Content defined by implementations
Comments	There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.
Control	0..*
Type	Extension
Alternate Names	extensions, user content
Slicing	This element introduces a set of slices on `Extension.extension.extension`. The slices areUnordered and Open, and can be differentiated using the following discriminators: value @ url
32. Extension.extension:value.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Short	identifies the meaning of the extension
Comments	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.
Control	1..1
Type	uri
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
XML Format	In the XML format, this property is represented as an attribute.
Fixed Value	`value`
34. Extension.extension:value.value[x]
Definition	A value that defines the context specified in this context of use. The interpretation of the value is defined by the code.
Short	Value that defines the context
Control	1..1
Type	Reference(Cross-version Profile for R5.PlanDefinition for use in FHIR STU3, PlanDefinition, Cross-version Profile for R5.ResearchStudy for use in FHIR STU3, ResearchStudy, Cross-version Profile for R5.InsurancePlan for use in FHIR STU3, Basic, Cross-version Profile for R5.HealthcareService for use in FHIR STU3, HealthcareService, Cross-version Profile for R5.Group for use in FHIR STU3, Group, Cross-version Profile for R5.Location for use in FHIR STU3, Location, Cross-version Profile for R5.Organization for use in FHIR STU3, Organization)
[x] Note	SeeChoice of Data Typesfor further information about how to use [x]
36. Extension.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Short	identifies the meaning of the extension
Comments	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.
Control	1..1
Type	uri
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
XML Format	In the XML format, this property is represented as an attribute.
Fixed Value	`http://hl7.org/fhir/5.0/StructureDefinition/extension-Evidence.useContext`
38. Extension.value[x]
Definition	Value of extension - may be a resource or one of a constrained set of the data types (see Extensibility in the spec for list).
Short	Value of extension
Control	0..0
Type	Choice of: base64Binary, boolean, code, date, dateTime, decimal, id, instant, integer, markdown, oid, positiveInt, string, time, unsignedInt, uri, Address, Age, Annotation, Attachment, CodeableConcept, Coding, ContactPoint, Count, Distance, Duration, HumanName, Identifier, Money, Period, Quantity, Range, Ratio, Reference, SampledData, Signature, Timing, Meta
Primitive Value	This primitive element may be present, or absent, or replaced by an extension