Introduction

The ehealth-definedquestion profile of StructureDefinition represents the concept of a DefinedQuestion. A DefinedQuestion is a standalone representation of a question and possibly its answer options that can be used in one or more Questionnaire resources. Although a Questionnaire can be constructed without being based on any DefinedQuestion, it is expected that a catalogue of DefinedQuestion will emerge over time and the particular DefinedQuestion will be reused in multiple Questionnaire.

The DefinedQuestion concept is based on ideas described in https://www.hl7.org/fhir/stu3/questionnaire.html#2.38.5.4. Whether a DefinedQuestion is referenced in a Questionnaire or not, it is the Questionnaire's own definition which takes precedence.

Scope and Usage

In the eHealth Infrastructure, a reference to a DefinedQuestion by url in a Questionnaire question is used to enable robust extraction in automated processing rule(s) of answer(s) to that question from corresponding QuestionnaireResponse. An answer in a QuestionnaireResponse is already unambiguously related to a question in a Questionnaire through the question's linkId. If the same question is used in another Questionnaire it will likely end up with a different linkId in that Questionnaire. By referencing a DefinedQuestion by its url in Questionnaire.item.definition, the same question can be referenced unambiguously in multiple Questionnaire.

Multiple DefinedQuestion with identical url can coexist as long as they have differing business versions in version. This way, different versions of the same question can have different answer options.

When using a DefinedQuestion in a Questionnaire, the Questionnaire.item.definition element must contain the url followed by a pipe and the business version thereby referencing a versioned DefinedQuestion.

An automated processing rule captured in a Library resource can, when extracting answer(s) to the question in a QuestionnaireResponse, choose to search for either the versioned reference or the version-less reference to a DefinedQuestion. The latter can be obtained by disregarding the pipe and business version in the rule logic.

The actual details of the DefinedQuestion's question and possible answers are described in the ElementDefinition found in either snapshot.element or differential.element.

• Key Elements Table
• Differential Table
• Snapshot Table
• Statistics/References
• All

Name	Flags	Card.	Type	Description & Constraints    Filter: Bindings Constraints Obligations
StructureDefinition	C	0..*	StructureDefinition	Structural Definition Constraints: sdf-0, sdf-1, sdf-15a, sdf-4, sdf-5, sdf-6, sdf-9, sdf-11, sdf-14, sdf-15, sdf-16, sdf-17, sdf-18, sdf-19, sdf-21, sdf-22, sdf-23
implicitRules	?!Σ	0..1	uri	A set of rules under which this content was created
modifierExtension	?!	0..*	Extension	Extensions that cannot be ignored
url	Σ	1..1	uri	Canonical identifier for this structure definition, represented as a URI (globally unique)
name	ΣC	1..1	string	Name for this structure definition (computer friendly)
status	?!Σ	1..1	code	draft | active | retired | unknown Binding: PublicationStatus (required): The lifecycle status of an artifact.
kind	Σ	1..1	code	primitive-type | complex-type | resource | logical Binding: StructureDefinitionKind (required): Defines the type of structure that a definition is describing.
abstract	Σ	1..1	boolean	Whether the structure is abstract
type	ΣC	1..1	uri	Type defined or constrained by this structure Binding: FHIRDefinedType (extensible): Either a resource or a data type, including logical model types.
Documentation for this format

Terminology Bindings

Path	Status	Usage	ValueSet	Version	Source
StructureDefinition.​status	Base	required	PublicationStatus	📍4.0.1	FHIR Std.
StructureDefinition.​kind	Base	required	StructureDefinitionKind	📍4.0.1	FHIR Std.
StructureDefinition.​type	Base	extensible	FHIRDefinedType	📍4.0.1	FHIR Std.

Constraints

Id	Grade	Path(s)	Description	Expression
dom-2	error	StructureDefinition	If the resource is contained in another resource, it SHALL NOT contain nested Resources	contained.contained.empty()
dom-3	error	StructureDefinition	If the resource is contained in another resource, it SHALL be referred to from elsewhere in the resource or SHALL refer to the containing resource	contained.where((('#'+id in (%resource.descendants().reference | %resource.descendants().as(canonical) | %resource.descendants().as(uri) | %resource.descendants().as(url))) or descendants().where(reference = '#').exists() or descendants().where(as(canonical) = '#').exists() or descendants().where(as(canonical) = '#').exists()).not()).trace('unmatched', id).empty()
dom-4	error	StructureDefinition	If a resource is contained in another resource, it SHALL NOT have a meta.versionId or a meta.lastUpdated	contained.meta.versionId.empty() and contained.meta.lastUpdated.empty()
dom-5	error	StructureDefinition	If a resource is contained in another resource, it SHALL NOT have a security label	contained.meta.security.empty()
dom-6	best practice	StructureDefinition	A resource should have narrative for robust management	text.`div`.exists()
ele-1	error	**ALL** elements	All FHIR elements must have a @value or children	hasValue() or (children().count() > id.count())
ext-1	error	**ALL** extensions	Must have either extensions or value[x], not both	extension.exists() != value.exists()
sdf-0	warning	StructureDefinition	Name should be usable as an identifier for the module by machine processing applications such as code generation	name.matches('[A-Z]([A-Za-z0-9_]){0,254}')
sdf-1	error	StructureDefinition	Element paths must be unique unless the structure is a constraint	derivation = 'constraint' or snapshot.element.select(path).isDistinct()
sdf-6	error	StructureDefinition	A structure must have either a differential, or a snapshot (or both)	snapshot.exists() or differential.exists()
sdf-14	error	StructureDefinition	All element definitions must have an id Requirements: elements have id	snapshot.element.all(id.exists()) and differential.element.all(id.exists())
sdf-15a	error	StructureDefinition	If the first element in a differential has no "." in the path and it's not a logical model, it has no type Requirements: No Type on the root element (differential)	(kind!='logical' and differential.element.first().path.contains('.').not()) implies differential.element.first().type.empty()
sdf-4	error	StructureDefinition	If the structure is not abstract, then there SHALL be a baseDefinition Requirements: Ensure that the base types are abstract	abstract = true or baseDefinition.exists()
sdf-5	error	StructureDefinition	If the structure defines an extension then the structure must have context information	type != 'Extension' or derivation = 'specialization' or (context.exists())
sdf-9	error	StructureDefinition	In any snapshot or differential, no label, code or requirements on an element without a "." in the path (e.g. the first element) Requirements: Because these 3 fields seem to be have overlapping meaning with the ones in the root of StructureDefinition	children().element.where(path.contains('.').not()).label.empty() and children().element.where(path.contains('.').not()).code.empty() and children().element.where(path.contains('.').not()).requirements.empty()
sdf-11	error	StructureDefinition	If there's a type, its content must match the path name in the first element of a snapshot Requirements: Ensure that the type is not inconsistent with the other information in the structure	kind != 'logical' implies snapshot.empty() or snapshot.element.first().path = type
sdf-15	error	StructureDefinition	The first element in a snapshot has no type unless model is a logical model. Requirements: No Type on the root element (snapshot)	kind!='logical' implies snapshot.element.first().type.empty()
sdf-16	error	StructureDefinition	All element definitions must have unique ids (snapshot) Requirements: element ids need to be unique	snapshot.element.all(id.exists()) and snapshot.element.id.trace('ids').isDistinct()
sdf-17	error	StructureDefinition	All element definitions must have unique ids (diff) Requirements: element ids need to be unique	differential.element.all(id.exists()) and differential.element.id.trace('ids').isDistinct()
sdf-18	error	StructureDefinition	Context Invariants can only be used for extensions Requirements: contextInvariant	contextInvariant.exists() implies type = 'Extension'
sdf-19	error	StructureDefinition	FHIR Specification models only use FHIR defined types Requirements: custom types only in logical models	url.startsWith('http://hl7.org/fhir/StructureDefinition') implies (differential.element.type.code.all(matches('^[a-zA-Z0-9]+$') or matches('^http:\\/\\/hl7\\.org\\/fhirpath\\/System\\.[A-Z][A-Za-z]+$')) and snapshot.element.type.code.all(matches('^[a-zA-Z0-9\\.]+$') or matches('^http:\\/\\/hl7\\.org\\/fhirpath\\/System\\.[A-Z][A-Za-z]+$')))
sdf-21	error	StructureDefinition	Default values can only be specified on specializations Requirements: no default values on data types or resources	differential.element.defaultValue.exists() implies (derivation = 'specialization')
sdf-22	error	StructureDefinition	FHIR Specification models never have default values Requirements: no default values on data types or resources	url.startsWith('http://hl7.org/fhir/StructureDefinition') implies (snapshot.element.defaultValue.empty() and differential.element.defaultValue.empty())
sdf-23	error	StructureDefinition	No slice name on root Requirements: no sliceName on root	(snapshot | differential).element.all(path.contains('.').not() implies sliceName.empty())

This structure is derived from StructureDefinition

Name	Flags	Card.	Type	Description & Constraints    Filter: Bindings Constraints Obligations
StructureDefinition		0..*	StructureDefinition	Structural Definition
Documentation for this format

Name	Flags	Card.	Type	Description & Constraints    Filter: Bindings Constraints Obligations
StructureDefinition	C	0..*	StructureDefinition	Structural Definition Constraints: sdf-0, sdf-1, sdf-15a, sdf-4, sdf-5, sdf-6, sdf-9, sdf-11, sdf-14, sdf-15, sdf-16, sdf-17, sdf-18, sdf-19, sdf-21, sdf-22, sdf-23
id	Σ	0..1	id	Logical id of this artifact
meta	Σ	0..1	Meta	Metadata about the resource
implicitRules	?!Σ	0..1	uri	A set of rules under which this content was created
language		0..1	code	Language of the resource content Binding: CommonLanguages (preferred): A human language. Additional Bindings Purpose AllLanguages Max Binding
text		0..1	Narrative	Text summary of the resource, for human interpretation This profile does not constrain the narrative in regard to content, language, or traceability to data elements
contained		0..*	Resource	Contained, inline Resources
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!	0..*	Extension	Extensions that cannot be ignored
url	Σ	1..1	uri	Canonical identifier for this structure definition, represented as a URI (globally unique)
identifier	Σ	0..*	Identifier	Additional identifier for the structure definition
version	Σ	0..1	string	Business version of the structure definition
name	ΣC	1..1	string	Name for this structure definition (computer friendly)
title	Σ	0..1	string	Name for this structure definition (human friendly)
status	?!Σ	1..1	code	draft | active | retired | unknown Binding: PublicationStatus (required): The lifecycle status of an artifact.
experimental	Σ	0..1	boolean	For testing purposes, not real usage
date	Σ	0..1	dateTime	Date last changed
publisher	Σ	0..1	string	Name of the publisher (organization or individual)
contact	Σ	0..*	ContactDetail	Contact details for the publisher
description		0..1	markdown	Natural language description of the structure definition
useContext	Σ	0..*	UsageContext	The context that the content is intended to support
jurisdiction	Σ	0..*	CodeableConcept	Intended jurisdiction for structure definition (if applicable) Binding: Jurisdiction ValueSet (extensible): Countries and regions within which this artifact is targeted for use.
purpose		0..1	markdown	Why this structure definition is defined
copyright		0..1	markdown	Use and/or publishing restrictions
keyword	Σ	0..*	Coding	Assist with indexing and finding Binding: DefinitionUseCodes (extensible): Codes for the meaning of the defined structure (SNOMED CT and LOINC codes, as an example).
fhirVersion	Σ	0..1	code	FHIR Version this StructureDefinition targets Binding: FHIRVersion (required): All published FHIR Versions.
mapping	C	0..*	BackboneElement	External specification that the content is mapped to Constraints: sdf-2
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored even if unrecognized
identity		1..1	id	Internal id when this mapping is used
uri	C	0..1	uri	Identifies what this mapping refers to
name	C	0..1	string	Names what this mapping refers to
comment		0..1	string	Versions, Issues, Scope limitations etc.
kind	Σ	1..1	code	primitive-type | complex-type | resource | logical Binding: StructureDefinitionKind (required): Defines the type of structure that a definition is describing.
abstract	Σ	1..1	boolean	Whether the structure is abstract
context	ΣC	0..*	BackboneElement	If an extension, where it can be used in instances
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored even if unrecognized
type	Σ	1..1	code	fhirpath | element | extension Binding: ExtensionContextType (required): How an extension context is interpreted.
expression	Σ	1..1	string	Where the extension can be used in instances
contextInvariant	ΣC	0..*	string	FHIRPath invariants - when the extension can be used
type	ΣC	1..1	uri	Type defined or constrained by this structure Binding: FHIRDefinedType (extensible): Either a resource or a data type, including logical model types.
baseDefinition	ΣC	0..1	canonical(StructureDefinition)	Definition that this type is constrained/specialized from
derivation	Σ	0..1	code	specialization | constraint - How relates to base definition Binding: TypeDerivationRule (required): How a type relates to its baseDefinition.
snapshot	C	0..1	BackboneElement	Snapshot view of the structure Constraints: sdf-3, sdf-8, sdf-8b
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored even if unrecognized
element	C	1..*	ElementDefinition	Definition of elements in the resource (if no StructureDefinition) Constraints: sdf-10
differential	C	0..1	BackboneElement	Differential view of the structure Constraints: sdf-20, sdf-8a
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored even if unrecognized
element		1..*	ElementDefinition	Definition of elements in the resource (if no StructureDefinition)
Documentation for this format

Terminology Bindings

Path	Status	Usage	ValueSet	Version	Source
StructureDefinition.​language	Base	preferred	Common Languages	📍4.0.1	FHIR Std.
StructureDefinition.​status	Base	required	PublicationStatus	📍4.0.1	FHIR Std.
StructureDefinition.​jurisdiction	Base	extensible	Jurisdiction	📍4.0.1	FHIR Std.
StructureDefinition.​keyword	Base	extensible	Structure Definition Use Codes / Keywords	📍4.0.1	FHIR Std.
StructureDefinition.​fhirVersion	Base	required	FHIRVersion	📍4.0.1	FHIR Std.
StructureDefinition.​kind	Base	required	StructureDefinitionKind	📍4.0.1	FHIR Std.
StructureDefinition.​context.type	Base	required	ExtensionContextType	📍4.0.1	FHIR Std.
StructureDefinition.​type	Base	extensible	FHIRDefinedType	📍4.0.1	FHIR Std.
StructureDefinition.​derivation	Base	required	TypeDerivationRule	📍4.0.1	FHIR Std.

Constraints

Id	Grade	Path(s)	Description	Expression
dom-2	error	StructureDefinition	If the resource is contained in another resource, it SHALL NOT contain nested Resources	contained.contained.empty()
dom-3	error	StructureDefinition	If the resource is contained in another resource, it SHALL be referred to from elsewhere in the resource or SHALL refer to the containing resource	contained.where((('#'+id in (%resource.descendants().reference | %resource.descendants().as(canonical) | %resource.descendants().as(uri) | %resource.descendants().as(url))) or descendants().where(reference = '#').exists() or descendants().where(as(canonical) = '#').exists() or descendants().where(as(canonical) = '#').exists()).not()).trace('unmatched', id).empty()
dom-4	error	StructureDefinition	If a resource is contained in another resource, it SHALL NOT have a meta.versionId or a meta.lastUpdated	contained.meta.versionId.empty() and contained.meta.lastUpdated.empty()
dom-5	error	StructureDefinition	If a resource is contained in another resource, it SHALL NOT have a security label	contained.meta.security.empty()
dom-6	best practice	StructureDefinition	A resource should have narrative for robust management	text.`div`.exists()
ele-1	error	**ALL** elements	All FHIR elements must have a @value or children	hasValue() or (children().count() > id.count())
ext-1	error	**ALL** extensions	Must have either extensions or value[x], not both	extension.exists() != value.exists()
sdf-0	warning	StructureDefinition	Name should be usable as an identifier for the module by machine processing applications such as code generation	name.matches('[A-Z]([A-Za-z0-9_]){0,254}')
sdf-1	error	StructureDefinition	Element paths must be unique unless the structure is a constraint	derivation = 'constraint' or snapshot.element.select(path).isDistinct()
sdf-15a	error	StructureDefinition	If the first element in a differential has no "." in the path and it's not a logical model, it has no type Requirements: No Type on the root element (differential)	(kind!='logical' and differential.element.first().path.contains('.').not()) implies differential.element.first().type.empty()
sdf-2	error	StructureDefinition.mapping	Must have at least a name or a uri (or both)	name.exists() or uri.exists()
sdf-3	error	StructureDefinition.snapshot	Each element definition in a snapshot must have a formal definition and cardinalities	element.all(definition.exists() and min.exists() and max.exists())
sdf-4	error	StructureDefinition	If the structure is not abstract, then there SHALL be a baseDefinition Requirements: Ensure that the base types are abstract	abstract = true or baseDefinition.exists()
sdf-5	error	StructureDefinition	If the structure defines an extension then the structure must have context information	type != 'Extension' or derivation = 'specialization' or (context.exists())
sdf-6	error	StructureDefinition	A structure must have either a differential, or a snapshot (or both)	snapshot.exists() or differential.exists()
sdf-8	error	StructureDefinition.snapshot	All snapshot elements must start with the StructureDefinition's specified type for non-logical models, or with the same type name for logical models	(%resource.kind = 'logical' or element.first().path = %resource.type) and element.tail().all(path.startsWith(%resource.snapshot.element.first().path&'.'))
sdf-9	error	StructureDefinition	In any snapshot or differential, no label, code or requirements on an element without a "." in the path (e.g. the first element) Requirements: Because these 3 fields seem to be have overlapping meaning with the ones in the root of StructureDefinition	children().element.where(path.contains('.').not()).label.empty() and children().element.where(path.contains('.').not()).code.empty() and children().element.where(path.contains('.').not()).requirements.empty()
sdf-10	error	StructureDefinition.snapshot.element	provide either a binding reference or a description (or both) Requirements: binding is required	binding.empty() or binding.valueSet.exists() or binding.description.exists()
sdf-11	error	StructureDefinition	If there's a type, its content must match the path name in the first element of a snapshot Requirements: Ensure that the type is not inconsistent with the other information in the structure	kind != 'logical' implies snapshot.empty() or snapshot.element.first().path = type
sdf-14	error	StructureDefinition	All element definitions must have an id Requirements: elements have id	snapshot.element.all(id.exists()) and differential.element.all(id.exists())
sdf-15	error	StructureDefinition	The first element in a snapshot has no type unless model is a logical model. Requirements: No Type on the root element (snapshot)	kind!='logical' implies snapshot.element.first().type.empty()
sdf-16	error	StructureDefinition	All element definitions must have unique ids (snapshot) Requirements: element ids need to be unique	snapshot.element.all(id.exists()) and snapshot.element.id.trace('ids').isDistinct()
sdf-17	error	StructureDefinition	All element definitions must have unique ids (diff) Requirements: element ids need to be unique	differential.element.all(id.exists()) and differential.element.id.trace('ids').isDistinct()
sdf-18	error	StructureDefinition	Context Invariants can only be used for extensions Requirements: contextInvariant	contextInvariant.exists() implies type = 'Extension'
sdf-19	error	StructureDefinition	FHIR Specification models only use FHIR defined types Requirements: custom types only in logical models	url.startsWith('http://hl7.org/fhir/StructureDefinition') implies (differential.element.type.code.all(matches('^[a-zA-Z0-9]+$') or matches('^http:\\/\\/hl7\\.org\\/fhirpath\\/System\\.[A-Z][A-Za-z]+$')) and snapshot.element.type.code.all(matches('^[a-zA-Z0-9\\.]+$') or matches('^http:\\/\\/hl7\\.org\\/fhirpath\\/System\\.[A-Z][A-Za-z]+$')))
sdf-20	error	StructureDefinition.differential	No slicing on the root element Requirements: no slicing on root	element.where(path.contains('.').not()).slicing.empty()
sdf-21	error	StructureDefinition	Default values can only be specified on specializations Requirements: no default values on data types or resources	differential.element.defaultValue.exists() implies (derivation = 'specialization')
sdf-22	error	StructureDefinition	FHIR Specification models never have default values Requirements: no default values on data types or resources	url.startsWith('http://hl7.org/fhir/StructureDefinition') implies (snapshot.element.defaultValue.empty() and differential.element.defaultValue.empty())
sdf-23	error	StructureDefinition	No slice name on root Requirements: no sliceName on root	(snapshot | differential).element.all(path.contains('.').not() implies sliceName.empty())
sdf-8a	error	StructureDefinition.differential	In any differential, all the elements must start with the StructureDefinition's specified type for non-logical models, or with the same type name for logical models	(%resource.kind = 'logical' or element.first().path.startsWith(%resource.type)) and (element.tail().empty() or element.tail().all(path.startsWith(%resource.differential.element.first().path.replaceMatches('\\..*','')&'.')))
sdf-8b	error	StructureDefinition.snapshot	All snapshot elements must have a base definition	element.all(base.exists())

Key Elements View

Name	Flags	Card.	Type	Description & Constraints    Filter: Bindings Constraints Obligations
StructureDefinition	C	0..*	StructureDefinition	Structural Definition Constraints: sdf-0, sdf-1, sdf-15a, sdf-4, sdf-5, sdf-6, sdf-9, sdf-11, sdf-14, sdf-15, sdf-16, sdf-17, sdf-18, sdf-19, sdf-21, sdf-22, sdf-23
implicitRules	?!Σ	0..1	uri	A set of rules under which this content was created
modifierExtension	?!	0..*	Extension	Extensions that cannot be ignored
url	Σ	1..1	uri	Canonical identifier for this structure definition, represented as a URI (globally unique)
name	ΣC	1..1	string	Name for this structure definition (computer friendly)
status	?!Σ	1..1	code	draft | active | retired | unknown Binding: PublicationStatus (required): The lifecycle status of an artifact.
kind	Σ	1..1	code	primitive-type | complex-type | resource | logical Binding: StructureDefinitionKind (required): Defines the type of structure that a definition is describing.
abstract	Σ	1..1	boolean	Whether the structure is abstract
type	ΣC	1..1	uri	Type defined or constrained by this structure Binding: FHIRDefinedType (extensible): Either a resource or a data type, including logical model types.
Documentation for this format

Terminology Bindings

Path	Status	Usage	ValueSet	Version	Source
StructureDefinition.​status	Base	required	PublicationStatus	📍4.0.1	FHIR Std.
StructureDefinition.​kind	Base	required	StructureDefinitionKind	📍4.0.1	FHIR Std.
StructureDefinition.​type	Base	extensible	FHIRDefinedType	📍4.0.1	FHIR Std.

Constraints

Id	Grade	Path(s)	Description	Expression
dom-2	error	StructureDefinition	If the resource is contained in another resource, it SHALL NOT contain nested Resources	contained.contained.empty()
dom-3	error	StructureDefinition	If the resource is contained in another resource, it SHALL be referred to from elsewhere in the resource or SHALL refer to the containing resource	contained.where((('#'+id in (%resource.descendants().reference | %resource.descendants().as(canonical) | %resource.descendants().as(uri) | %resource.descendants().as(url))) or descendants().where(reference = '#').exists() or descendants().where(as(canonical) = '#').exists() or descendants().where(as(canonical) = '#').exists()).not()).trace('unmatched', id).empty()
dom-4	error	StructureDefinition	If a resource is contained in another resource, it SHALL NOT have a meta.versionId or a meta.lastUpdated	contained.meta.versionId.empty() and contained.meta.lastUpdated.empty()
dom-5	error	StructureDefinition	If a resource is contained in another resource, it SHALL NOT have a security label	contained.meta.security.empty()
dom-6	best practice	StructureDefinition	A resource should have narrative for robust management	text.`div`.exists()
ele-1	error	**ALL** elements	All FHIR elements must have a @value or children	hasValue() or (children().count() > id.count())
ext-1	error	**ALL** extensions	Must have either extensions or value[x], not both	extension.exists() != value.exists()
sdf-0	warning	StructureDefinition	Name should be usable as an identifier for the module by machine processing applications such as code generation	name.matches('[A-Z]([A-Za-z0-9_]){0,254}')
sdf-1	error	StructureDefinition	Element paths must be unique unless the structure is a constraint	derivation = 'constraint' or snapshot.element.select(path).isDistinct()
sdf-6	error	StructureDefinition	A structure must have either a differential, or a snapshot (or both)	snapshot.exists() or differential.exists()
sdf-14	error	StructureDefinition	All element definitions must have an id Requirements: elements have id	snapshot.element.all(id.exists()) and differential.element.all(id.exists())
sdf-15a	error	StructureDefinition	If the first element in a differential has no "." in the path and it's not a logical model, it has no type Requirements: No Type on the root element (differential)	(kind!='logical' and differential.element.first().path.contains('.').not()) implies differential.element.first().type.empty()
sdf-4	error	StructureDefinition	If the structure is not abstract, then there SHALL be a baseDefinition Requirements: Ensure that the base types are abstract	abstract = true or baseDefinition.exists()
sdf-5	error	StructureDefinition	If the structure defines an extension then the structure must have context information	type != 'Extension' or derivation = 'specialization' or (context.exists())
sdf-9	error	StructureDefinition	In any snapshot or differential, no label, code or requirements on an element without a "." in the path (e.g. the first element) Requirements: Because these 3 fields seem to be have overlapping meaning with the ones in the root of StructureDefinition	children().element.where(path.contains('.').not()).label.empty() and children().element.where(path.contains('.').not()).code.empty() and children().element.where(path.contains('.').not()).requirements.empty()
sdf-11	error	StructureDefinition	If there's a type, its content must match the path name in the first element of a snapshot Requirements: Ensure that the type is not inconsistent with the other information in the structure	kind != 'logical' implies snapshot.empty() or snapshot.element.first().path = type
sdf-15	error	StructureDefinition	The first element in a snapshot has no type unless model is a logical model. Requirements: No Type on the root element (snapshot)	kind!='logical' implies snapshot.element.first().type.empty()
sdf-16	error	StructureDefinition	All element definitions must have unique ids (snapshot) Requirements: element ids need to be unique	snapshot.element.all(id.exists()) and snapshot.element.id.trace('ids').isDistinct()
sdf-17	error	StructureDefinition	All element definitions must have unique ids (diff) Requirements: element ids need to be unique	differential.element.all(id.exists()) and differential.element.id.trace('ids').isDistinct()
sdf-18	error	StructureDefinition	Context Invariants can only be used for extensions Requirements: contextInvariant	contextInvariant.exists() implies type = 'Extension'
sdf-19	error	StructureDefinition	FHIR Specification models only use FHIR defined types Requirements: custom types only in logical models	url.startsWith('http://hl7.org/fhir/StructureDefinition') implies (differential.element.type.code.all(matches('^[a-zA-Z0-9]+$') or matches('^http:\\/\\/hl7\\.org\\/fhirpath\\/System\\.[A-Z][A-Za-z]+$')) and snapshot.element.type.code.all(matches('^[a-zA-Z0-9\\.]+$') or matches('^http:\\/\\/hl7\\.org\\/fhirpath\\/System\\.[A-Z][A-Za-z]+$')))
sdf-21	error	StructureDefinition	Default values can only be specified on specializations Requirements: no default values on data types or resources	differential.element.defaultValue.exists() implies (derivation = 'specialization')
sdf-22	error	StructureDefinition	FHIR Specification models never have default values Requirements: no default values on data types or resources	url.startsWith('http://hl7.org/fhir/StructureDefinition') implies (snapshot.element.defaultValue.empty() and differential.element.defaultValue.empty())
sdf-23	error	StructureDefinition	No slice name on root Requirements: no sliceName on root	(snapshot | differential).element.all(path.contains('.').not() implies sliceName.empty())

Differential View

This structure is derived from StructureDefinition

Name	Flags	Card.	Type	Description & Constraints    Filter: Bindings Constraints Obligations
StructureDefinition		0..*	StructureDefinition	Structural Definition
Documentation for this format

Snapshot View

Name	Flags	Card.	Type	Description & Constraints    Filter: Bindings Constraints Obligations
StructureDefinition	C	0..*	StructureDefinition	Structural Definition Constraints: sdf-0, sdf-1, sdf-15a, sdf-4, sdf-5, sdf-6, sdf-9, sdf-11, sdf-14, sdf-15, sdf-16, sdf-17, sdf-18, sdf-19, sdf-21, sdf-22, sdf-23
id	Σ	0..1	id	Logical id of this artifact
meta	Σ	0..1	Meta	Metadata about the resource
implicitRules	?!Σ	0..1	uri	A set of rules under which this content was created
language		0..1	code	Language of the resource content Binding: CommonLanguages (preferred): A human language. Additional Bindings Purpose AllLanguages Max Binding
text		0..1	Narrative	Text summary of the resource, for human interpretation This profile does not constrain the narrative in regard to content, language, or traceability to data elements
contained		0..*	Resource	Contained, inline Resources
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!	0..*	Extension	Extensions that cannot be ignored
url	Σ	1..1	uri	Canonical identifier for this structure definition, represented as a URI (globally unique)
identifier	Σ	0..*	Identifier	Additional identifier for the structure definition
version	Σ	0..1	string	Business version of the structure definition
name	ΣC	1..1	string	Name for this structure definition (computer friendly)
title	Σ	0..1	string	Name for this structure definition (human friendly)
status	?!Σ	1..1	code	draft | active | retired | unknown Binding: PublicationStatus (required): The lifecycle status of an artifact.
experimental	Σ	0..1	boolean	For testing purposes, not real usage
date	Σ	0..1	dateTime	Date last changed
publisher	Σ	0..1	string	Name of the publisher (organization or individual)
contact	Σ	0..*	ContactDetail	Contact details for the publisher
description		0..1	markdown	Natural language description of the structure definition
useContext	Σ	0..*	UsageContext	The context that the content is intended to support
jurisdiction	Σ	0..*	CodeableConcept	Intended jurisdiction for structure definition (if applicable) Binding: Jurisdiction ValueSet (extensible): Countries and regions within which this artifact is targeted for use.
purpose		0..1	markdown	Why this structure definition is defined
copyright		0..1	markdown	Use and/or publishing restrictions
keyword	Σ	0..*	Coding	Assist with indexing and finding Binding: DefinitionUseCodes (extensible): Codes for the meaning of the defined structure (SNOMED CT and LOINC codes, as an example).
fhirVersion	Σ	0..1	code	FHIR Version this StructureDefinition targets Binding: FHIRVersion (required): All published FHIR Versions.
mapping	C	0..*	BackboneElement	External specification that the content is mapped to Constraints: sdf-2
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored even if unrecognized
identity		1..1	id	Internal id when this mapping is used
uri	C	0..1	uri	Identifies what this mapping refers to
name	C	0..1	string	Names what this mapping refers to
comment		0..1	string	Versions, Issues, Scope limitations etc.
kind	Σ	1..1	code	primitive-type | complex-type | resource | logical Binding: StructureDefinitionKind (required): Defines the type of structure that a definition is describing.
abstract	Σ	1..1	boolean	Whether the structure is abstract
context	ΣC	0..*	BackboneElement	If an extension, where it can be used in instances
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored even if unrecognized
type	Σ	1..1	code	fhirpath | element | extension Binding: ExtensionContextType (required): How an extension context is interpreted.
expression	Σ	1..1	string	Where the extension can be used in instances
contextInvariant	ΣC	0..*	string	FHIRPath invariants - when the extension can be used
type	ΣC	1..1	uri	Type defined or constrained by this structure Binding: FHIRDefinedType (extensible): Either a resource or a data type, including logical model types.
baseDefinition	ΣC	0..1	canonical(StructureDefinition)	Definition that this type is constrained/specialized from
derivation	Σ	0..1	code	specialization | constraint - How relates to base definition Binding: TypeDerivationRule (required): How a type relates to its baseDefinition.
snapshot	C	0..1	BackboneElement	Snapshot view of the structure Constraints: sdf-3, sdf-8, sdf-8b
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored even if unrecognized
element	C	1..*	ElementDefinition	Definition of elements in the resource (if no StructureDefinition) Constraints: sdf-10
differential	C	0..1	BackboneElement	Differential view of the structure Constraints: sdf-20, sdf-8a
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored even if unrecognized
element		1..*	ElementDefinition	Definition of elements in the resource (if no StructureDefinition)
Documentation for this format

Terminology Bindings

Path	Status	Usage	ValueSet	Version	Source
StructureDefinition.​language	Base	preferred	Common Languages	📍4.0.1	FHIR Std.
StructureDefinition.​status	Base	required	PublicationStatus	📍4.0.1	FHIR Std.
StructureDefinition.​jurisdiction	Base	extensible	Jurisdiction	📍4.0.1	FHIR Std.
StructureDefinition.​keyword	Base	extensible	Structure Definition Use Codes / Keywords	📍4.0.1	FHIR Std.
StructureDefinition.​fhirVersion	Base	required	FHIRVersion	📍4.0.1	FHIR Std.
StructureDefinition.​kind	Base	required	StructureDefinitionKind	📍4.0.1	FHIR Std.
StructureDefinition.​context.type	Base	required	ExtensionContextType	📍4.0.1	FHIR Std.
StructureDefinition.​type	Base	extensible	FHIRDefinedType	📍4.0.1	FHIR Std.
StructureDefinition.​derivation	Base	required	TypeDerivationRule	📍4.0.1	FHIR Std.

Constraints

Id	Grade	Path(s)	Description	Expression
dom-2	error	StructureDefinition	If the resource is contained in another resource, it SHALL NOT contain nested Resources	contained.contained.empty()
dom-3	error	StructureDefinition	If the resource is contained in another resource, it SHALL be referred to from elsewhere in the resource or SHALL refer to the containing resource	contained.where((('#'+id in (%resource.descendants().reference | %resource.descendants().as(canonical) | %resource.descendants().as(uri) | %resource.descendants().as(url))) or descendants().where(reference = '#').exists() or descendants().where(as(canonical) = '#').exists() or descendants().where(as(canonical) = '#').exists()).not()).trace('unmatched', id).empty()
dom-4	error	StructureDefinition	If a resource is contained in another resource, it SHALL NOT have a meta.versionId or a meta.lastUpdated	contained.meta.versionId.empty() and contained.meta.lastUpdated.empty()
dom-5	error	StructureDefinition	If a resource is contained in another resource, it SHALL NOT have a security label	contained.meta.security.empty()
dom-6	best practice	StructureDefinition	A resource should have narrative for robust management	text.`div`.exists()
ele-1	error	**ALL** elements	All FHIR elements must have a @value or children	hasValue() or (children().count() > id.count())
ext-1	error	**ALL** extensions	Must have either extensions or value[x], not both	extension.exists() != value.exists()
sdf-0	warning	StructureDefinition	Name should be usable as an identifier for the module by machine processing applications such as code generation	name.matches('[A-Z]([A-Za-z0-9_]){0,254}')
sdf-1	error	StructureDefinition	Element paths must be unique unless the structure is a constraint	derivation = 'constraint' or snapshot.element.select(path).isDistinct()
sdf-15a	error	StructureDefinition	If the first element in a differential has no "." in the path and it's not a logical model, it has no type Requirements: No Type on the root element (differential)	(kind!='logical' and differential.element.first().path.contains('.').not()) implies differential.element.first().type.empty()
sdf-2	error	StructureDefinition.mapping	Must have at least a name or a uri (or both)	name.exists() or uri.exists()
sdf-3	error	StructureDefinition.snapshot	Each element definition in a snapshot must have a formal definition and cardinalities	element.all(definition.exists() and min.exists() and max.exists())
sdf-4	error	StructureDefinition	If the structure is not abstract, then there SHALL be a baseDefinition Requirements: Ensure that the base types are abstract	abstract = true or baseDefinition.exists()
sdf-5	error	StructureDefinition	If the structure defines an extension then the structure must have context information	type != 'Extension' or derivation = 'specialization' or (context.exists())
sdf-6	error	StructureDefinition	A structure must have either a differential, or a snapshot (or both)	snapshot.exists() or differential.exists()
sdf-8	error	StructureDefinition.snapshot	All snapshot elements must start with the StructureDefinition's specified type for non-logical models, or with the same type name for logical models	(%resource.kind = 'logical' or element.first().path = %resource.type) and element.tail().all(path.startsWith(%resource.snapshot.element.first().path&'.'))
sdf-9	error	StructureDefinition	In any snapshot or differential, no label, code or requirements on an element without a "." in the path (e.g. the first element) Requirements: Because these 3 fields seem to be have overlapping meaning with the ones in the root of StructureDefinition	children().element.where(path.contains('.').not()).label.empty() and children().element.where(path.contains('.').not()).code.empty() and children().element.where(path.contains('.').not()).requirements.empty()
sdf-10	error	StructureDefinition.snapshot.element	provide either a binding reference or a description (or both) Requirements: binding is required	binding.empty() or binding.valueSet.exists() or binding.description.exists()
sdf-11	error	StructureDefinition	If there's a type, its content must match the path name in the first element of a snapshot Requirements: Ensure that the type is not inconsistent with the other information in the structure	kind != 'logical' implies snapshot.empty() or snapshot.element.first().path = type
sdf-14	error	StructureDefinition	All element definitions must have an id Requirements: elements have id	snapshot.element.all(id.exists()) and differential.element.all(id.exists())
sdf-15	error	StructureDefinition	The first element in a snapshot has no type unless model is a logical model. Requirements: No Type on the root element (snapshot)	kind!='logical' implies snapshot.element.first().type.empty()
sdf-16	error	StructureDefinition	All element definitions must have unique ids (snapshot) Requirements: element ids need to be unique	snapshot.element.all(id.exists()) and snapshot.element.id.trace('ids').isDistinct()
sdf-17	error	StructureDefinition	All element definitions must have unique ids (diff) Requirements: element ids need to be unique	differential.element.all(id.exists()) and differential.element.id.trace('ids').isDistinct()
sdf-18	error	StructureDefinition	Context Invariants can only be used for extensions Requirements: contextInvariant	contextInvariant.exists() implies type = 'Extension'
sdf-19	error	StructureDefinition	FHIR Specification models only use FHIR defined types Requirements: custom types only in logical models	url.startsWith('http://hl7.org/fhir/StructureDefinition') implies (differential.element.type.code.all(matches('^[a-zA-Z0-9]+$') or matches('^http:\\/\\/hl7\\.org\\/fhirpath\\/System\\.[A-Z][A-Za-z]+$')) and snapshot.element.type.code.all(matches('^[a-zA-Z0-9\\.]+$') or matches('^http:\\/\\/hl7\\.org\\/fhirpath\\/System\\.[A-Z][A-Za-z]+$')))
sdf-20	error	StructureDefinition.differential	No slicing on the root element Requirements: no slicing on root	element.where(path.contains('.').not()).slicing.empty()
sdf-21	error	StructureDefinition	Default values can only be specified on specializations Requirements: no default values on data types or resources	differential.element.defaultValue.exists() implies (derivation = 'specialization')
sdf-22	error	StructureDefinition	FHIR Specification models never have default values Requirements: no default values on data types or resources	url.startsWith('http://hl7.org/fhir/StructureDefinition') implies (snapshot.element.defaultValue.empty() and differential.element.defaultValue.empty())
sdf-23	error	StructureDefinition	No slice name on root Requirements: no sliceName on root	(snapshot | differential).element.all(path.contains('.').not() implies sliceName.empty())
sdf-8a	error	StructureDefinition.differential	In any differential, all the elements must start with the StructureDefinition's specified type for non-logical models, or with the same type name for logical models	(%resource.kind = 'logical' or element.first().path.startsWith(%resource.type)) and (element.tail().empty() or element.tail().all(path.startsWith(%resource.differential.element.first().path.replaceMatches('\\..*','')&'.')))
sdf-8b	error	StructureDefinition.snapshot	All snapshot elements must have a base definition	element.all(base.exists())

This structure is derived from StructureDefinition

Summary