UK Core Implementation Guide 1.0.0

StructureDefinition Extension-UKCore-Evidence

A reference to results of investigations that confirmed the certainty of the diagnosis. Examples might include results of skin prick allergy tests.

Purpose

This extension extends the AllergyIntolerance resource to support the exchange of information describing the reference to results of investigations that confirmed the certainty of the diagnosis, which is currently not supported by the FHIR standard.

Guidance

An optional extension for a reference to a UKCore-DiagnosticReport resource to share the results of investigations that confirmed the certainty of the allergy or intolerance diagnosis.

Context of Use
Use on element	AllergyIntolerance

Snapshot View

Extension	I		Extension	Element Id Extension Short description A reference to results of investigations that confirmed the certainty of the diagnosis Definition A reference to results of investigations that confirmed the certainty of the diagnosis. Data Type Extension Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ext-1:Must have either extensions or value[x], not both `extension.exists() != value.exists()` Mappings rim:n/a rim:N/A
url		1..1	System.StringFixed Value	Element Id Extension.url Short description identifies the meaning of the extension Definition Source of the definition for the extension code - a logical name or a URL. 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. Data Type System.String Fixed Value https://fhir.hl7.org.uk/StructureDefinition/Extension-UKCore-Evidence Mappings rim:N/A
value[x]		1..1		Element Id Extension.value[x] Short description A reference to results of investigations that confirmed the certainty of the diagnosis Definition A reference to results of investigations that confirmed the certainty of the diagnosis. Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
reference	Σ I	0..1	string	There are no (further) constraints on this element Element Id Extension.value[x].reference Short description Literal reference, Relative, internal or absolute URL Definition A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources. Comments Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
type	Σ	0..1	uriBinding	There are no (further) constraints on this element Element Id Extension.value[x].type Short description Type the reference refers to (e.g. "Patient") Definition The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent. The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources). Comments This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified. Data Type uri Binding Aa resource (or, for logical models, the URI of the logical model). ResourceType (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
identifier	Σ	0..1	Identifier	There are no (further) constraints on this element Element Id Extension.value[x].identifier Short description Logical reference, when literal reference is not known Definition An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference. Comments When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy. When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it. Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation\|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any). Data Type Identifier Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CX / EI (occasionally, more often EI maps to a resource id or a URL) rim:II - The Identifier class is a little looser than the v3 type II because it allows URIs as well as registered OIDs or GUIDs. Also maps to Role[classCode=IDENT] servd:Identifier rim:.identifier
use	Σ ?!	0..1	codeBinding	There are no (further) constraints on this element Element Id Extension.value[x].identifier.use Short description usual \| official \| temp \| secondary \| old (If known) Definition The purpose of this identifier. Requirements Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers. Comments Applications can assume that an identifier is permanent unless it explicitly says that it is temporary. Data Type code Binding Identifies the purpose for this identifier, if known . IdentifierUse (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:N/A rim:Role.code or implied by context
type	Σ	0..1	CodeableConceptBinding	There are no (further) constraints on this element Element Id Extension.value[x].identifier.type Short description Description of identifier Definition A coded type for the identifier that can be used to determine which identifier to use for a specific purpose. Requirements Allows users to make use of identifiers when the identifier system is not known. Comments This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type. Data Type CodeableConcept Binding A coded type for an identifier that can be used to determine which identifier to use for a specific purpose. Identifier Type Codes (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE/CNE/CWE rim:CD orim:fhir:CodeableConcept rdfs:subClassOf dt:CD v2:CX.5 rim:Role.code or implied by context
system	Σ	0..1	uri	There are no (further) constraints on this element Element Id Extension.value[x].identifier.system Short description The namespace for the identifier value Definition Establishes the namespace for the value - that is, a URL that describes a set values that are unique. Requirements There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers. Comments Identifier.system is always case sensitive. Data Type uri Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General http://www.acme.com/identifiers/patient Mappings rim:n/a v2:CX.4 / EI-2-4 rim:II.root or Role.id.root servd:./IdentifierType
value	Σ	0..1	string	There are no (further) constraints on this element Element Id Extension.value[x].identifier.value Short description The value that is unique Definition The portion of the identifier typically relevant to the user and which is unique within the context of the system. Comments If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value extension. Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General 123456 Mappings rim:n/a v2:CX.1 / EI.1 rim:II.extension or II.root if system indicates OID or GUID (Or Role.id.extension or root) servd:./Value
period	Σ I	0..1	Period	There are no (further) constraints on this element Element Id Extension.value[x].identifier.period Short description Time period when id is/was valid for use Definition Time period during which identifier is/was valid for use. Comments A Period specifies a range of time; the context of use will specify whether the entire range applies (e.g. "the patient was an inpatient of the hospital for this time range") or one value from the range applies (e.g. "give to the patient between these two times"). Period is not used for a duration (a measure of elapsed time). See Duration. Data Type Period Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` per-1:If present, start SHALL have a lower value than end `start.hasValue().not() or end.hasValue().not() or (start <= end)` Mappings rim:n/a v2:DR rim:IVL<TS>[lowClosed="true" and highClosed="true"] or URG<TS>[lowClosed="true" and highClosed="true"] v2:CX.7 + CX.8 rim:Role.effectiveTime or implied by context servd:./StartDate and ./EndDate
assigner	Σ I	0..1	Reference(UK Core Organization)	Element Id Extension.value[x].identifier.assigner Short description Organization that issued id (may be just text) Definition Organization that issued/manages the identifier. Comments The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization. Data Type Reference(UK Core Organization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) v2:CX.4 / (CX.4,CX.9,CX.10) rim:II.assigningAuthorityName but note that this is an improper use by the definition of the field. Also Role.scoper servd:./IdentifierIssuingAuthority
display	Σ	0..1	string	There are no (further) constraints on this element Element Id Extension.value[x].display Short description Text alternative for the resource Definition Plain text narrative that identifies the resource in addition to the resource reference. Comments This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
valueReference			Reference(UK Core DiagnosticReport)	Data Type Reference(UK Core DiagnosticReport)

Differential View

Extension	I		Extension	Element Id Extension Short description A reference to results of investigations that confirmed the certainty of the diagnosis Definition A reference to results of investigations that confirmed the certainty of the diagnosis. Data Type Extension Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ext-1:Must have either extensions or value[x], not both `extension.exists() != value.exists()` Mappings rim:n/a rim:N/A
url		1..1	System.StringFixed Value	Element Id Extension.url Short description identifies the meaning of the extension Definition Source of the definition for the extension code - a logical name or a URL. 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. Data Type System.String Fixed Value https://fhir.hl7.org.uk/StructureDefinition/Extension-UKCore-Evidence Mappings rim:N/A
value[x]		1..1		Element Id Extension.value[x] Short description A reference to results of investigations that confirmed the certainty of the diagnosis Definition A reference to results of investigations that confirmed the certainty of the diagnosis. Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
reference	Σ I	0..1	string	There are no (further) constraints on this element Element Id Extension.value[x].reference Short description Literal reference, Relative, internal or absolute URL Definition A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources. Comments Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
type	Σ	0..1	uriBinding	There are no (further) constraints on this element Element Id Extension.value[x].type Short description Type the reference refers to (e.g. "Patient") Definition The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent. The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources). Comments This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified. Data Type uri Binding Aa resource (or, for logical models, the URI of the logical model). ResourceType (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
identifier	Σ	0..1	Identifier	There are no (further) constraints on this element Element Id Extension.value[x].identifier Short description Logical reference, when literal reference is not known Definition An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference. Comments When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy. When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it. Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation\|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any). Data Type Identifier Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CX / EI (occasionally, more often EI maps to a resource id or a URL) rim:II - The Identifier class is a little looser than the v3 type II because it allows URIs as well as registered OIDs or GUIDs. Also maps to Role[classCode=IDENT] servd:Identifier rim:.identifier
use	Σ ?!	0..1	codeBinding	There are no (further) constraints on this element Element Id Extension.value[x].identifier.use Short description usual \| official \| temp \| secondary \| old (If known) Definition The purpose of this identifier. Requirements Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers. Comments Applications can assume that an identifier is permanent unless it explicitly says that it is temporary. Data Type code Binding Identifies the purpose for this identifier, if known . IdentifierUse (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:N/A rim:Role.code or implied by context
type	Σ	0..1	CodeableConceptBinding	There are no (further) constraints on this element Element Id Extension.value[x].identifier.type Short description Description of identifier Definition A coded type for the identifier that can be used to determine which identifier to use for a specific purpose. Requirements Allows users to make use of identifiers when the identifier system is not known. Comments This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type. Data Type CodeableConcept Binding A coded type for an identifier that can be used to determine which identifier to use for a specific purpose. Identifier Type Codes (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE/CNE/CWE rim:CD orim:fhir:CodeableConcept rdfs:subClassOf dt:CD v2:CX.5 rim:Role.code or implied by context
system	Σ	0..1	uri	There are no (further) constraints on this element Element Id Extension.value[x].identifier.system Short description The namespace for the identifier value Definition Establishes the namespace for the value - that is, a URL that describes a set values that are unique. Requirements There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers. Comments Identifier.system is always case sensitive. Data Type uri Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General http://www.acme.com/identifiers/patient Mappings rim:n/a v2:CX.4 / EI-2-4 rim:II.root or Role.id.root servd:./IdentifierType
value	Σ	0..1	string	There are no (further) constraints on this element Element Id Extension.value[x].identifier.value Short description The value that is unique Definition The portion of the identifier typically relevant to the user and which is unique within the context of the system. Comments If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value extension. Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General 123456 Mappings rim:n/a v2:CX.1 / EI.1 rim:II.extension or II.root if system indicates OID or GUID (Or Role.id.extension or root) servd:./Value
period	Σ I	0..1	Period	There are no (further) constraints on this element Element Id Extension.value[x].identifier.period Short description Time period when id is/was valid for use Definition Time period during which identifier is/was valid for use. Comments A Period specifies a range of time; the context of use will specify whether the entire range applies (e.g. "the patient was an inpatient of the hospital for this time range") or one value from the range applies (e.g. "give to the patient between these two times"). Period is not used for a duration (a measure of elapsed time). See Duration. Data Type Period Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` per-1:If present, start SHALL have a lower value than end `start.hasValue().not() or end.hasValue().not() or (start <= end)` Mappings rim:n/a v2:DR rim:IVL<TS>[lowClosed="true" and highClosed="true"] or URG<TS>[lowClosed="true" and highClosed="true"] v2:CX.7 + CX.8 rim:Role.effectiveTime or implied by context servd:./StartDate and ./EndDate
assigner	Σ I	0..1	Reference(UK Core Organization)	Element Id Extension.value[x].identifier.assigner Short description Organization that issued id (may be just text) Definition Organization that issued/manages the identifier. Comments The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization. Data Type Reference(UK Core Organization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) v2:CX.4 / (CX.4,CX.9,CX.10) rim:II.assigningAuthorityName but note that this is an improper use by the definition of the field. Also Role.scoper servd:./IdentifierIssuingAuthority
display	Σ	0..1	string	There are no (further) constraints on this element Element Id Extension.value[x].display Short description Text alternative for the resource Definition Plain text narrative that identifies the resource in addition to the resource reference. Comments This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
valueReference			Reference(UK Core DiagnosticReport)	Data Type Reference(UK Core DiagnosticReport)

Hybrid View

Extension	I		Extension	Element Id Extension Short description A reference to results of investigations that confirmed the certainty of the diagnosis Definition A reference to results of investigations that confirmed the certainty of the diagnosis. Data Type Extension Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ext-1:Must have either extensions or value[x], not both `extension.exists() != value.exists()` Mappings rim:n/a rim:N/A
url		1..1	System.StringFixed Value	Element Id Extension.url Short description identifies the meaning of the extension Definition Source of the definition for the extension code - a logical name or a URL. 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. Data Type System.String Fixed Value https://fhir.hl7.org.uk/StructureDefinition/Extension-UKCore-Evidence Mappings rim:N/A
value[x]		1..1		Element Id Extension.value[x] Short description A reference to results of investigations that confirmed the certainty of the diagnosis Definition A reference to results of investigations that confirmed the certainty of the diagnosis. Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
reference	Σ I	0..1	string	There are no (further) constraints on this element Element Id Extension.value[x].reference Short description Literal reference, Relative, internal or absolute URL Definition A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources. Comments Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
type	Σ	0..1	uriBinding	There are no (further) constraints on this element Element Id Extension.value[x].type Short description Type the reference refers to (e.g. "Patient") Definition The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent. The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources). Comments This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified. Data Type uri Binding Aa resource (or, for logical models, the URI of the logical model). ResourceType (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
identifier	Σ	0..1	Identifier	There are no (further) constraints on this element Element Id Extension.value[x].identifier Short description Logical reference, when literal reference is not known Definition An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference. Comments When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy. When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it. Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation\|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any). Data Type Identifier Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CX / EI (occasionally, more often EI maps to a resource id or a URL) rim:II - The Identifier class is a little looser than the v3 type II because it allows URIs as well as registered OIDs or GUIDs. Also maps to Role[classCode=IDENT] servd:Identifier rim:.identifier
use	Σ ?!	0..1	codeBinding	There are no (further) constraints on this element Element Id Extension.value[x].identifier.use Short description usual \| official \| temp \| secondary \| old (If known) Definition The purpose of this identifier. Requirements Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers. Comments Applications can assume that an identifier is permanent unless it explicitly says that it is temporary. Data Type code Binding Identifies the purpose for this identifier, if known . IdentifierUse (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:N/A rim:Role.code or implied by context
type	Σ	0..1	CodeableConceptBinding	There are no (further) constraints on this element Element Id Extension.value[x].identifier.type Short description Description of identifier Definition A coded type for the identifier that can be used to determine which identifier to use for a specific purpose. Requirements Allows users to make use of identifiers when the identifier system is not known. Comments This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type. Data Type CodeableConcept Binding A coded type for an identifier that can be used to determine which identifier to use for a specific purpose. Identifier Type Codes (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE/CNE/CWE rim:CD orim:fhir:CodeableConcept rdfs:subClassOf dt:CD v2:CX.5 rim:Role.code or implied by context
system	Σ	0..1	uri	There are no (further) constraints on this element Element Id Extension.value[x].identifier.system Short description The namespace for the identifier value Definition Establishes the namespace for the value - that is, a URL that describes a set values that are unique. Requirements There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers. Comments Identifier.system is always case sensitive. Data Type uri Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General http://www.acme.com/identifiers/patient Mappings rim:n/a v2:CX.4 / EI-2-4 rim:II.root or Role.id.root servd:./IdentifierType
value	Σ	0..1	string	There are no (further) constraints on this element Element Id Extension.value[x].identifier.value Short description The value that is unique Definition The portion of the identifier typically relevant to the user and which is unique within the context of the system. Comments If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value extension. Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General 123456 Mappings rim:n/a v2:CX.1 / EI.1 rim:II.extension or II.root if system indicates OID or GUID (Or Role.id.extension or root) servd:./Value
period	Σ I	0..1	Period	There are no (further) constraints on this element Element Id Extension.value[x].identifier.period Short description Time period when id is/was valid for use Definition Time period during which identifier is/was valid for use. Comments A Period specifies a range of time; the context of use will specify whether the entire range applies (e.g. "the patient was an inpatient of the hospital for this time range") or one value from the range applies (e.g. "give to the patient between these two times"). Period is not used for a duration (a measure of elapsed time). See Duration. Data Type Period Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` per-1:If present, start SHALL have a lower value than end `start.hasValue().not() or end.hasValue().not() or (start <= end)` Mappings rim:n/a v2:DR rim:IVL<TS>[lowClosed="true" and highClosed="true"] or URG<TS>[lowClosed="true" and highClosed="true"] v2:CX.7 + CX.8 rim:Role.effectiveTime or implied by context servd:./StartDate and ./EndDate
assigner	Σ I	0..1	Reference(UK Core Organization)	Element Id Extension.value[x].identifier.assigner Short description Organization that issued id (may be just text) Definition Organization that issued/manages the identifier. Comments The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization. Data Type Reference(UK Core Organization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) v2:CX.4 / (CX.4,CX.9,CX.10) rim:II.assigningAuthorityName but note that this is an improper use by the definition of the field. Also Role.scoper servd:./IdentifierIssuingAuthority
display	Σ	0..1	string	There are no (further) constraints on this element Element Id Extension.value[x].display Short description Text alternative for the resource Definition Plain text narrative that identifies the resource in addition to the resource reference. Comments This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
valueReference			Reference(UK Core DiagnosticReport)	Data Type Reference(UK Core DiagnosticReport)

Table View

Extension		..
Extension.url		..
Extension.value[x]	Reference(UK Core DiagnosticReport)	1..
Extension.value[x].identifier		..
Extension.value[x].identifier.assigner	Reference(UK Core Organization)	..

XML View

<StructureDefinition xmlns="http://hl7.org/fhir">
    <id value="Extension-UKCore-Evidence" />
    <url value="https://fhir.hl7.org.uk/StructureDefinition/Extension-UKCore-Evidence" />
    <version value="2.1.0" />
    <name value="ExtensionUKCoreEvidence" />
    <title value="Extension UK Core Evidence" />
    <status value="active" />
    <date value="2021-09-10" />
    <publisher value="HL7 UK" />
    <contact>
        <name value="HL7 UK" />
        <telecom>
            <system value="email" />
            <value value="secretariat@hl7.org.uk" />
            <use value="work" />
            <rank value="1" />
        </telecom>
    </contact>
    <contact>
        <name value="NHS Digital" />
        <telecom>
            <system value="email" />
            <value value="interoperabilityteam@nhs.net" />
            <use value="work" />
            <rank value="2" />
        </telecom>
    </contact>
    <description value="A reference to results of investigations that confirmed the certainty of the diagnosis.  Examples might include results of skin prick allergy tests." />
    <purpose value="This extension extends the AllergyIntolerance resource to support the exchange of information describing the reference to results of investigations that confirmed the certainty of the diagnosis, which is currently not supported by the FHIR standard." />
    <copyright value="Copyright &#169; 2021+ HL7 UK Licensed under the Apache License, Version 2.0 (the &quot;License&quot;); you may not use this file except in compliance with the License. You may obtain a copy of the License at  http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an &quot;AS IS&quot; BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. HL7&#174; FHIR&#174; standard Copyright &#169; 2011+ HL7 The HL7&#174; FHIR&#174; standard is used under the FHIR license. You may obtain a copy of the FHIR license at  https://www.hl7.org/fhir/license.html." />
    <fhirVersion value="4.0.1" />
    <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="AllergyIntolerance" />
    </context>
    <type value="Extension" />
    <baseDefinition value="http://hl7.org/fhir/StructureDefinition/Extension" />
    <derivation value="constraint" />
    <differential>
        <element id="Extension">
            <path value="Extension" />
            <short value="A reference to results of investigations that confirmed the certainty of the diagnosis" />
            <definition value="A reference to results of investigations that confirmed the certainty of the diagnosis." />
        </element>
        <element id="Extension.url">
            <path value="Extension.url" />
            <fixedUri value="https://fhir.hl7.org.uk/StructureDefinition/Extension-UKCore-Evidence" />
        </element>
        <element id="Extension.value[x]">
            <path value="Extension.value[x]" />
            <short value="A reference to results of investigations that confirmed the certainty of the diagnosis" />
            <definition value="A reference to results of investigations that confirmed the certainty of the diagnosis." />
            <min value="1" />
            <type>
                <code value="Reference" />
                <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-DiagnosticReport" />
            </type>
        </element>
        <element id="Extension.value[x].identifier.assigner">
            <path value="Extension.value[x].identifier.assigner" />
            <type>
                <code value="Reference" />
                <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-Organization" />
            </type>
        </element>
    </differential>
</StructureDefinition>

JSON View

{
    "resourceType": "StructureDefinition",
    "id": "Extension-UKCore-Evidence",
    "url": "https://fhir.hl7.org.uk/StructureDefinition/Extension-UKCore-Evidence",
    "version": "2.1.0",
    "name": "ExtensionUKCoreEvidence",
    "title": "Extension UK Core Evidence",
    "status": "active",
    "date": "2021-09-10",
    "publisher": "HL7 UK",
    "contact":  [
        {
            "name": "HL7 UK",
            "telecom":  [
                {
                    "system": "email",
                    "value": "secretariat@hl7.org.uk",
                    "use": "work",
                    "rank": 1
                }
            ]
        },
        {
            "name": "NHS Digital",
            "telecom":  [
                {
                    "system": "email",
                    "value": "interoperabilityteam@nhs.net",
                    "use": "work",
                    "rank": 2
                }
            ]
        }
    ],
    "description": "A reference to results of investigations that confirmed the certainty of the diagnosis.  Examples might include results of skin prick allergy tests.",
    "purpose": "This extension extends the AllergyIntolerance resource to support the exchange of information describing the reference to results of investigations that confirmed the certainty of the diagnosis, which is currently not supported by the FHIR standard.",
    "copyright": "Copyright © 2021+ HL7 UK Licensed under the Apache License, Version 2.0 (the \"License\"); you may not use this file except in compliance with the License. You may obtain a copy of the License at  http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an \"AS IS\" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. HL7® FHIR® standard Copyright © 2011+ HL7 The HL7® FHIR® standard is used under the FHIR license. You may obtain a copy of the FHIR license at  https://www.hl7.org/fhir/license.html.",
    "fhirVersion": "4.0.1",
    "mapping":  [
        {
            "identity": "rim",
            "uri": "http://hl7.org/v3",
            "name": "RIM Mapping"
        }
    ],
    "kind": "complex-type",
    "abstract": false,
    "context":  [
        {
            "type": "element",
            "expression": "AllergyIntolerance"
        }
    ],
    "type": "Extension",
    "baseDefinition": "http://hl7.org/fhir/StructureDefinition/Extension",
    "derivation": "constraint",
    "differential": {
        "element":  [
            {
                "id": "Extension",
                "path": "Extension",
                "short": "A reference to results of investigations that confirmed the certainty of the diagnosis",
                "definition": "A reference to results of investigations that confirmed the certainty of the diagnosis."
            },
            {
                "id": "Extension.url",
                "path": "Extension.url",
                "fixedUri": "https://fhir.hl7.org.uk/StructureDefinition/Extension-UKCore-Evidence"
            },
            {
                "id": "Extension.value[x]",
                "path": "Extension.value[x]",
                "short": "A reference to results of investigations that confirmed the certainty of the diagnosis",
                "definition": "A reference to results of investigations that confirmed the certainty of the diagnosis.",
                "min": 1,
                "type":  [
                    {
                        "code": "Reference",
                        "targetProfile":  [
                            "https://fhir.hl7.org.uk/StructureDefinition/UKCore-DiagnosticReport"
                        ]
                    }
                ]
            },
            {
                "id": "Extension.value[x].identifier.assigner",
                "path": "Extension.value[x].identifier.assigner",
                "type":  [
                    {
                        "code": "Reference",
                        "targetProfile":  [
                            "https://fhir.hl7.org.uk/StructureDefinition/UKCore-Organization"
                        ]
                    }
                ]
            }
        ]
    }
}

Examples

Example UKCore-AllergyIntolerance-Extension-Evidence