See Comparison with other national and international IGs for a comparison between AU Core profiles and profiles in other implementation guides.

Usage scenarios

The following are supported usage scenarios for this profile:

• Query for observations of smoking status associated with a patient
• Record or update an observation of smoking status associated with a patient

Profile specific implementation guidance

• Observation.category provides an efficient way of supporting system interactions, e.g. restricting searches. Implementers need to understand that data categorisation is somewhat subjective. The categorisation applied by the source may not align with a receiver’s expectations.
• Additional codes that translate or map to the Observation code or category codes are allowed. For example providing both a local code and the required code.

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

This structure is derived from Observation

Name	Flags	Card.	Type	Description & Constraints
Observation	C	0..*	Observation	Smoking status au-core-obs-02: At least value or data absent reason shall be present
status	SO	1..1	code	registered | preliminary | final | amended + Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
Slices for category	SO	1..*	CodeableConcept	Classification of type of observation Slice: Unordered, Open by pattern:$this Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
category:socialHistory		1..1	CodeableConcept	Classification of type of observation Required Pattern: At least the following
coding		1..*	Coding	Code defined by a terminology system Fixed Value: (complex)
system		1..1	uri	Identity of the terminology system Fixed Value: http://terminology.hl7.org/CodeSystem/observation-category
code		1..1	code	Symbol in syntax defined by the system Fixed Value: social-history
code	SO	1..1	CodeableConcept	Type of observation (code / type) Required Pattern: At least the following Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
coding		1..*	Coding	Code defined by a terminology system Fixed Value: (complex)
system		1..1	uri	Identity of the terminology system Fixed Value: http://snomed.info/sct
code		1..1	code	Symbol in syntax defined by the system Fixed Value: 1747861000168109
Slices for coding		0..*	Coding	Code defined by a terminology system Slice: Unordered, Open by value:code, value:system
coding:loincSmokingStatus		0..1	Coding	LOINC Smoking Status
system		1..1	uri	Identity of the terminology system Fixed Value: http://loinc.org
code		1..1	code	Symbol in syntax defined by the system Fixed Value: 72166-2
subject	SO	1..1	Reference(AU Core Patient)	Who and/or what the observation is about Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
effective[x]	SOC	1..1	dateTime	Date, and optionally time, the observation was performed au-core-obs-01: Date shall be at least to day Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
value[x]	SOC	0..1	CodeableConcept	Actual result Binding: Smoking Status (extensible) Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
dataAbsentReason	SOC	0..1	CodeableConcept	Why the result is missing Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
Documentation for this format

Terminology Bindings (Differential)

Path	Conformance	ValueSet	URI
Observation.value[x]	extensible	SmokingStatus https://healthterminologies.gov.au/fhir/ValueSet/smoking-status-1 from https://tx.ontoserver.csiro.au/fhir

Constraints

Id	Grade	Path(s)	Details	Requirements
au-core-obs-01	error	Observation.effective[x]	Date shall be at least to day : $this is DateTime implies $this.toString().length() >= 8
au-core-obs-02	error	Observation	At least value or data absent reason shall be present : dataAbsentReason.exists() or value.exists()

Name	Flags	Card.	Type	Description & Constraints
Observation	C	0..*	Observation	Smoking status obs-6: dataAbsentReason SHALL only be present if Observation.value[x] is not present obs-7: If Observation.code is the same as an Observation.component.code then the value element associated with the code SHALL NOT be present au-core-obs-02: At least value or data absent reason shall be present
implicitRules	?!Σ	0..1	uri	A set of rules under which this content was created
modifierExtension	?!	0..*	Extension	Extensions that cannot be ignored
status	?!SOΣ	1..1	code	registered | preliminary | final | amended + Binding: ObservationStatus (required): Codes providing the status of an observation. Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
Slices for category	SO	1..*	CodeableConcept	Classification of type of observation Slice: Unordered, Open by pattern:$this Binding: ObservationCategoryCodes (preferred): Codes for high level observation categories. Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
category:socialHistory		1..1	CodeableConcept	Classification of type of observation Binding: ObservationCategoryCodes (preferred): Codes for high level observation categories. Required Pattern: At least the following
coding		1..*	Coding	Code defined by a terminology system Fixed Value: (complex)
system		1..1	uri	Identity of the terminology system Fixed Value: http://terminology.hl7.org/CodeSystem/observation-category
code		1..1	code	Symbol in syntax defined by the system Fixed Value: social-history
code	SOΣ	1..1	CodeableConcept	Type of observation (code / type) Binding: LOINCCodes (example): Codes identifying names of simple observations. Required Pattern: At least the following Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
coding		1..*	Coding	Code defined by a terminology system Fixed Value: (complex)
system		1..1	uri	Identity of the terminology system Fixed Value: http://snomed.info/sct
code		1..1	code	Symbol in syntax defined by the system Fixed Value: 1747861000168109
Slices for coding	Σ	0..*	Coding	Code defined by a terminology system Slice: Unordered, Open by value:code, value:system
coding:loincSmokingStatus	Σ	0..1	Coding	LOINC Smoking Status
system	Σ	1..1	uri	Identity of the terminology system Fixed Value: http://loinc.org
code	Σ	1..1	code	Symbol in syntax defined by the system Fixed Value: 72166-2
subject	SOΣ	1..1	Reference(AU Core Patient)	Who and/or what the observation is about Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
effective[x]	SOΣC	1..1	dateTime	Date, and optionally time, the observation was performed au-core-obs-01: Date shall be at least to day Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
value[x]	SOΣC	0..1	CodeableConcept	Actual result Binding: Smoking Status (extensible) Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
dataAbsentReason	SOC	0..1	CodeableConcept	Why the result is missing Binding: DataAbsentReason (extensible): Codes specifying why the result (Observation.value[x]) is missing. Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
Documentation for this format

Terminology Bindings

Path	Conformance	ValueSet / Code	URI
Observation.status	required	ObservationStatus http://hl7.org/fhir/ValueSet/observation-status|4.0.1 from the FHIR Standard
Observation.category	preferred	ObservationCategoryCodes http://hl7.org/fhir/ValueSet/observation-category from the FHIR Standard
Observation.category:socialHistory	preferred	Pattern: social-history http://hl7.org/fhir/ValueSet/observation-category from the FHIR Standard
Observation.code	example	Pattern: SNOMED-CT Code 1747861000168109 http://hl7.org/fhir/ValueSet/observation-codes from the FHIR Standard
Observation.value[x]	extensible	SmokingStatus https://healthterminologies.gov.au/fhir/ValueSet/smoking-status-1 from https://tx.ontoserver.csiro.au/fhir
Observation.dataAbsentReason	extensible	DataAbsentReason http://hl7.org/fhir/ValueSet/data-absent-reason from the FHIR Standard

Constraints

Id	Grade	Path(s)	Details	Requirements
au-core-obs-01	error	Observation.effective[x]	Date shall be at least to day : $this is DateTime implies $this.toString().length() >= 8
au-core-obs-02	error	Observation	At least value or data absent reason shall be present : dataAbsentReason.exists() or value.exists()
dom-2	error	Observation	If the resource is contained in another resource, it SHALL NOT contain nested Resources : contained.contained.empty()
dom-3	error	Observation	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	Observation	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	Observation	If a resource is contained in another resource, it SHALL NOT have a security label : contained.meta.security.empty()
dom-6	best practice	Observation	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()
obs-6	error	Observation	dataAbsentReason SHALL only be present if Observation.value[x] is not present : dataAbsentReason.empty() or value.empty()
obs-7	error	Observation	If Observation.code is the same as an Observation.component.code then the value element associated with the code SHALL NOT be present : value.empty() or component.code.where(coding.intersect(%resource.code.coding).exists()).empty()

Name	Flags	Card.	Type	Description & Constraints
Observation	C	0..*	Observation	Smoking status obs-6: dataAbsentReason SHALL only be present if Observation.value[x] is not present obs-7: If Observation.code is the same as an Observation.component.code then the value element associated with the code SHALL NOT be present au-core-obs-02: At least value or data absent reason shall be present
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
contained		0..*	Resource	Contained, inline Resources
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!	0..*	Extension	Extensions that cannot be ignored
identifier	Σ	0..*	Identifier	Business Identifier for observation
basedOn	Σ	0..*	Reference(CarePlan | DeviceRequest | ImmunizationRecommendation | MedicationRequest | NutritionOrder | ServiceRequest)	Fulfills plan, proposal or order
partOf	Σ	0..*	Reference(MedicationAdministration | MedicationDispense | MedicationStatement | Procedure | Immunization | ImagingStudy)	Part of referenced event
status	?!SOΣ	1..1	code	registered | preliminary | final | amended + Binding: ObservationStatus (required): Codes providing the status of an observation. Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
Slices for category	SO	1..*	CodeableConcept	Classification of type of observation Slice: Unordered, Open by pattern:$this Binding: ObservationCategoryCodes (preferred): Codes for high level observation categories. Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
category:socialHistory		1..1	CodeableConcept	Classification of type of observation Binding: ObservationCategoryCodes (preferred): Codes for high level observation categories. Required Pattern: At least the following
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
coding		1..*	Coding	Code defined by a terminology system Fixed Value: (complex)
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
system		1..1	uri	Identity of the terminology system Fixed Value: http://terminology.hl7.org/CodeSystem/observation-category
version		0..1	string	Version of the system - if relevant
code		1..1	code	Symbol in syntax defined by the system Fixed Value: social-history
display		0..1	string	Representation defined by the system
userSelected		0..1	boolean	If this coding was chosen directly by the user
text		0..1	string	Plain text representation of the concept
code	SOΣ	1..1	CodeableConcept	Type of observation (code / type) Binding: LOINCCodes (example): Codes identifying names of simple observations. Required Pattern: At least the following Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
coding		1..*	Coding	Code defined by a terminology system Fixed Value: (complex)
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
system		1..1	uri	Identity of the terminology system Fixed Value: http://snomed.info/sct
version		0..1	string	Version of the system - if relevant
code		1..1	code	Symbol in syntax defined by the system Fixed Value: 1747861000168109
display		0..1	string	Representation defined by the system
userSelected		0..1	boolean	If this coding was chosen directly by the user
text		0..1	string	Plain text representation of the concept
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations Slice: Unordered, Open by value:url
Slices for coding	Σ	0..*	Coding	Code defined by a terminology system Slice: Unordered, Open by value:code, value:system
coding:loincSmokingStatus	Σ	0..1	Coding	LOINC Smoking Status
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations Slice: Unordered, Open by value:url
system	Σ	1..1	uri	Identity of the terminology system Fixed Value: http://loinc.org
version	Σ	0..1	string	Version of the system - if relevant
code	Σ	1..1	code	Symbol in syntax defined by the system Fixed Value: 72166-2
display	Σ	0..1	string	Representation defined by the system
userSelected	Σ	0..1	boolean	If this coding was chosen directly by the user
text	Σ	0..1	string	Plain text representation of the concept
subject	SOΣ	1..1	Reference(AU Core Patient)	Who and/or what the observation is about Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
focus	Σ	0..*	Reference(Resource)	What the observation is about, when it is not about the subject of record
encounter	Σ	0..1	Reference(Encounter)	Healthcare event during which this observation is made
effective[x]	SOΣC	1..1	dateTime	Date, and optionally time, the observation was performed au-core-obs-01: Date shall be at least to day Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
issued	Σ	0..1	instant	Date/Time this version was made available
performer	Σ	0..*	Reference(Practitioner | PractitionerRole | Organization | CareTeam | Patient | RelatedPerson)	Who is responsible for the observation
value[x]	SOΣC	0..1	CodeableConcept	Actual result Binding: Smoking Status (extensible) Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
dataAbsentReason	SOC	0..1	CodeableConcept	Why the result is missing Binding: DataAbsentReason (extensible): Codes specifying why the result (Observation.value[x]) is missing. Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
interpretation		0..*	CodeableConcept	High, low, normal, etc. Binding: ObservationInterpretationCodes (extensible): Codes identifying interpretations of observations.
note		0..*	Annotation	Comments about the observation
bodySite		0..1	CodeableConcept	Observed body part Binding: SNOMEDCTBodyStructures (example): Codes describing anatomical locations. May include laterality.
method		0..1	CodeableConcept	How it was done Binding: ObservationMethods (example): Methods for simple observations.
specimen		0..1	Reference(Specimen)	Specimen used for this observation
device		0..1	Reference(Device | DeviceMetric)	(Measurement) Device
referenceRange	C	0..*	BackboneElement	Provides guide for interpretation obs-3: Must have at least a low or a high or text
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
low	C	0..1	SimpleQuantity	Low Range, if relevant
high	C	0..1	SimpleQuantity	High Range, if relevant
type		0..1	CodeableConcept	Reference range qualifier Binding: ObservationReferenceRangeMeaningCodes (preferred): Code for the meaning of a reference range.
appliesTo		0..*	CodeableConcept	Reference range population Binding: ObservationReferenceRangeAppliesToCodes (example): Codes identifying the population the reference range applies to.
age		0..1	Range	Applicable age range, if relevant
text		0..1	string	Text based reference range in an observation
hasMember	Σ	0..*	Reference(Observation | QuestionnaireResponse | MolecularSequence)	Related resource that belongs to the Observation group
derivedFrom	Σ	0..*	Reference(DocumentReference | ImagingStudy | Media | QuestionnaireResponse | Observation | MolecularSequence)	Related measurements the observation is made from
component	Σ	0..*	BackboneElement	Component results
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
code	Σ	1..1	CodeableConcept	Type of component observation (code / type) Binding: LOINCCodes (example): Codes identifying names of simple observations.
value[x]	Σ	0..1		Actual component result
valueQuantity			Quantity
valueCodeableConcept			CodeableConcept
valueString			string
valueBoolean			boolean
valueInteger			integer
valueRange			Range
valueRatio			Ratio
valueSampledData			SampledData
valueTime			time
valueDateTime			dateTime
valuePeriod			Period
dataAbsentReason	C	0..1	CodeableConcept	Why the component result is missing Binding: DataAbsentReason (extensible): Codes specifying why the result (Observation.value[x]) is missing.
interpretation		0..*	CodeableConcept	High, low, normal, etc. Binding: ObservationInterpretationCodes (extensible): Codes identifying interpretations of observations.
referenceRange		0..*	See referenceRange (Observation)	Provides guide for interpretation of component result
Documentation for this format

Terminology Bindings

Path	Conformance	ValueSet / Code	URI
Observation.language	preferred	CommonLanguages Additional Bindings Purpose AllLanguages Max Binding http://hl7.org/fhir/ValueSet/languages from the FHIR Standard
Observation.status	required	ObservationStatus http://hl7.org/fhir/ValueSet/observation-status|4.0.1 from the FHIR Standard
Observation.category	preferred	ObservationCategoryCodes http://hl7.org/fhir/ValueSet/observation-category from the FHIR Standard
Observation.category:socialHistory	preferred	Pattern: social-history http://hl7.org/fhir/ValueSet/observation-category from the FHIR Standard
Observation.code	example	Pattern: SNOMED-CT Code 1747861000168109 http://hl7.org/fhir/ValueSet/observation-codes from the FHIR Standard
Observation.value[x]	extensible	SmokingStatus https://healthterminologies.gov.au/fhir/ValueSet/smoking-status-1 from https://tx.ontoserver.csiro.au/fhir
Observation.dataAbsentReason	extensible	DataAbsentReason http://hl7.org/fhir/ValueSet/data-absent-reason from the FHIR Standard
Observation.interpretation	extensible	ObservationInterpretationCodes http://hl7.org/fhir/ValueSet/observation-interpretation from the FHIR Standard
Observation.bodySite	example	SNOMEDCTBodyStructures http://hl7.org/fhir/ValueSet/body-site from the FHIR Standard
Observation.method	example	ObservationMethods http://hl7.org/fhir/ValueSet/observation-methods from the FHIR Standard
Observation.referenceRange.type	preferred	ObservationReferenceRangeMeaningCodes http://hl7.org/fhir/ValueSet/referencerange-meaning from the FHIR Standard
Observation.referenceRange.appliesTo	example	ObservationReferenceRangeAppliesToCodes http://hl7.org/fhir/ValueSet/referencerange-appliesto from the FHIR Standard
Observation.component.code	example	LOINCCodes (a valid code from LOINC) http://hl7.org/fhir/ValueSet/observation-codes from the FHIR Standard
Observation.component.dataAbsentReason	extensible	DataAbsentReason http://hl7.org/fhir/ValueSet/data-absent-reason from the FHIR Standard
Observation.component.interpretation	extensible	ObservationInterpretationCodes http://hl7.org/fhir/ValueSet/observation-interpretation from the FHIR Standard

Constraints

Id	Grade	Path(s)	Details	Requirements
au-core-obs-01	error	Observation.effective[x]	Date shall be at least to day : $this is DateTime implies $this.toString().length() >= 8
au-core-obs-02	error	Observation	At least value or data absent reason shall be present : dataAbsentReason.exists() or value.exists()
dom-2	error	Observation	If the resource is contained in another resource, it SHALL NOT contain nested Resources : contained.contained.empty()
dom-3	error	Observation	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	Observation	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	Observation	If a resource is contained in another resource, it SHALL NOT have a security label : contained.meta.security.empty()
dom-6	best practice	Observation	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()
obs-3	error	Observation.referenceRange	Must have at least a low or a high or text : low.exists() or high.exists() or text.exists()
obs-6	error	Observation	dataAbsentReason SHALL only be present if Observation.value[x] is not present : dataAbsentReason.empty() or value.empty()
obs-7	error	Observation	If Observation.code is the same as an Observation.component.code then the value element associated with the code SHALL NOT be present : value.empty() or component.code.where(coding.intersect(%resource.code.coding).exists()).empty()

Differential View

This structure is derived from Observation

Name	Flags	Card.	Type	Description & Constraints
Observation	C	0..*	Observation	Smoking status au-core-obs-02: At least value or data absent reason shall be present
status	SO	1..1	code	registered | preliminary | final | amended + Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
Slices for category	SO	1..*	CodeableConcept	Classification of type of observation Slice: Unordered, Open by pattern:$this Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
category:socialHistory		1..1	CodeableConcept	Classification of type of observation Required Pattern: At least the following
coding		1..*	Coding	Code defined by a terminology system Fixed Value: (complex)
system		1..1	uri	Identity of the terminology system Fixed Value: http://terminology.hl7.org/CodeSystem/observation-category
code		1..1	code	Symbol in syntax defined by the system Fixed Value: social-history
code	SO	1..1	CodeableConcept	Type of observation (code / type) Required Pattern: At least the following Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
coding		1..*	Coding	Code defined by a terminology system Fixed Value: (complex)
system		1..1	uri	Identity of the terminology system Fixed Value: http://snomed.info/sct
code		1..1	code	Symbol in syntax defined by the system Fixed Value: 1747861000168109
Slices for coding		0..*	Coding	Code defined by a terminology system Slice: Unordered, Open by value:code, value:system
coding:loincSmokingStatus		0..1	Coding	LOINC Smoking Status
system		1..1	uri	Identity of the terminology system Fixed Value: http://loinc.org
code		1..1	code	Symbol in syntax defined by the system Fixed Value: 72166-2
subject	SO	1..1	Reference(AU Core Patient)	Who and/or what the observation is about Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
effective[x]	SOC	1..1	dateTime	Date, and optionally time, the observation was performed au-core-obs-01: Date shall be at least to day Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
value[x]	SOC	0..1	CodeableConcept	Actual result Binding: Smoking Status (extensible) Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
dataAbsentReason	SOC	0..1	CodeableConcept	Why the result is missing Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
Documentation for this format

Terminology Bindings (Differential)

Path	Conformance	ValueSet	URI
Observation.value[x]	extensible	SmokingStatus https://healthterminologies.gov.au/fhir/ValueSet/smoking-status-1 from https://tx.ontoserver.csiro.au/fhir

Constraints

Id	Grade	Path(s)	Details	Requirements
au-core-obs-01	error	Observation.effective[x]	Date shall be at least to day : $this is DateTime implies $this.toString().length() >= 8
au-core-obs-02	error	Observation	At least value or data absent reason shall be present : dataAbsentReason.exists() or value.exists()

Key Elements View

Name	Flags	Card.	Type	Description & Constraints
Observation	C	0..*	Observation	Smoking status obs-6: dataAbsentReason SHALL only be present if Observation.value[x] is not present obs-7: If Observation.code is the same as an Observation.component.code then the value element associated with the code SHALL NOT be present au-core-obs-02: At least value or data absent reason shall be present
implicitRules	?!Σ	0..1	uri	A set of rules under which this content was created
modifierExtension	?!	0..*	Extension	Extensions that cannot be ignored
status	?!SOΣ	1..1	code	registered | preliminary | final | amended + Binding: ObservationStatus (required): Codes providing the status of an observation. Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
Slices for category	SO	1..*	CodeableConcept	Classification of type of observation Slice: Unordered, Open by pattern:$this Binding: ObservationCategoryCodes (preferred): Codes for high level observation categories. Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
category:socialHistory		1..1	CodeableConcept	Classification of type of observation Binding: ObservationCategoryCodes (preferred): Codes for high level observation categories. Required Pattern: At least the following
coding		1..*	Coding	Code defined by a terminology system Fixed Value: (complex)
system		1..1	uri	Identity of the terminology system Fixed Value: http://terminology.hl7.org/CodeSystem/observation-category
code		1..1	code	Symbol in syntax defined by the system Fixed Value: social-history
code	SOΣ	1..1	CodeableConcept	Type of observation (code / type) Binding: LOINCCodes (example): Codes identifying names of simple observations. Required Pattern: At least the following Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
coding		1..*	Coding	Code defined by a terminology system Fixed Value: (complex)
system		1..1	uri	Identity of the terminology system Fixed Value: http://snomed.info/sct
code		1..1	code	Symbol in syntax defined by the system Fixed Value: 1747861000168109
Slices for coding	Σ	0..*	Coding	Code defined by a terminology system Slice: Unordered, Open by value:code, value:system
coding:loincSmokingStatus	Σ	0..1	Coding	LOINC Smoking Status
system	Σ	1..1	uri	Identity of the terminology system Fixed Value: http://loinc.org
code	Σ	1..1	code	Symbol in syntax defined by the system Fixed Value: 72166-2
subject	SOΣ	1..1	Reference(AU Core Patient)	Who and/or what the observation is about Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
effective[x]	SOΣC	1..1	dateTime	Date, and optionally time, the observation was performed au-core-obs-01: Date shall be at least to day Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
value[x]	SOΣC	0..1	CodeableConcept	Actual result Binding: Smoking Status (extensible) Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
dataAbsentReason	SOC	0..1	CodeableConcept	Why the result is missing Binding: DataAbsentReason (extensible): Codes specifying why the result (Observation.value[x]) is missing. Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
Documentation for this format

Terminology Bindings

Path	Conformance	ValueSet / Code	URI
Observation.status	required	ObservationStatus http://hl7.org/fhir/ValueSet/observation-status|4.0.1 from the FHIR Standard
Observation.category	preferred	ObservationCategoryCodes http://hl7.org/fhir/ValueSet/observation-category from the FHIR Standard
Observation.category:socialHistory	preferred	Pattern: social-history http://hl7.org/fhir/ValueSet/observation-category from the FHIR Standard
Observation.code	example	Pattern: SNOMED-CT Code 1747861000168109 http://hl7.org/fhir/ValueSet/observation-codes from the FHIR Standard
Observation.value[x]	extensible	SmokingStatus https://healthterminologies.gov.au/fhir/ValueSet/smoking-status-1 from https://tx.ontoserver.csiro.au/fhir
Observation.dataAbsentReason	extensible	DataAbsentReason http://hl7.org/fhir/ValueSet/data-absent-reason from the FHIR Standard

Constraints

Id	Grade	Path(s)	Details	Requirements
au-core-obs-01	error	Observation.effective[x]	Date shall be at least to day : $this is DateTime implies $this.toString().length() >= 8
au-core-obs-02	error	Observation	At least value or data absent reason shall be present : dataAbsentReason.exists() or value.exists()
dom-2	error	Observation	If the resource is contained in another resource, it SHALL NOT contain nested Resources : contained.contained.empty()
dom-3	error	Observation	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	Observation	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	Observation	If a resource is contained in another resource, it SHALL NOT have a security label : contained.meta.security.empty()
dom-6	best practice	Observation	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()
obs-6	error	Observation	dataAbsentReason SHALL only be present if Observation.value[x] is not present : dataAbsentReason.empty() or value.empty()
obs-7	error	Observation	If Observation.code is the same as an Observation.component.code then the value element associated with the code SHALL NOT be present : value.empty() or component.code.where(coding.intersect(%resource.code.coding).exists()).empty()

Snapshot View

Name	Flags	Card.	Type	Description & Constraints
Observation	C	0..*	Observation	Smoking status obs-6: dataAbsentReason SHALL only be present if Observation.value[x] is not present obs-7: If Observation.code is the same as an Observation.component.code then the value element associated with the code SHALL NOT be present au-core-obs-02: At least value or data absent reason shall be present
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
contained		0..*	Resource	Contained, inline Resources
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!	0..*	Extension	Extensions that cannot be ignored
identifier	Σ	0..*	Identifier	Business Identifier for observation
basedOn	Σ	0..*	Reference(CarePlan | DeviceRequest | ImmunizationRecommendation | MedicationRequest | NutritionOrder | ServiceRequest)	Fulfills plan, proposal or order
partOf	Σ	0..*	Reference(MedicationAdministration | MedicationDispense | MedicationStatement | Procedure | Immunization | ImagingStudy)	Part of referenced event
status	?!SOΣ	1..1	code	registered | preliminary | final | amended + Binding: ObservationStatus (required): Codes providing the status of an observation. Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
Slices for category	SO	1..*	CodeableConcept	Classification of type of observation Slice: Unordered, Open by pattern:$this Binding: ObservationCategoryCodes (preferred): Codes for high level observation categories. Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
category:socialHistory		1..1	CodeableConcept	Classification of type of observation Binding: ObservationCategoryCodes (preferred): Codes for high level observation categories. Required Pattern: At least the following
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
coding		1..*	Coding	Code defined by a terminology system Fixed Value: (complex)
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
system		1..1	uri	Identity of the terminology system Fixed Value: http://terminology.hl7.org/CodeSystem/observation-category
version		0..1	string	Version of the system - if relevant
code		1..1	code	Symbol in syntax defined by the system Fixed Value: social-history
display		0..1	string	Representation defined by the system
userSelected		0..1	boolean	If this coding was chosen directly by the user
text		0..1	string	Plain text representation of the concept
code	SOΣ	1..1	CodeableConcept	Type of observation (code / type) Binding: LOINCCodes (example): Codes identifying names of simple observations. Required Pattern: At least the following Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
coding		1..*	Coding	Code defined by a terminology system Fixed Value: (complex)
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
system		1..1	uri	Identity of the terminology system Fixed Value: http://snomed.info/sct
version		0..1	string	Version of the system - if relevant
code		1..1	code	Symbol in syntax defined by the system Fixed Value: 1747861000168109
display		0..1	string	Representation defined by the system
userSelected		0..1	boolean	If this coding was chosen directly by the user
text		0..1	string	Plain text representation of the concept
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations Slice: Unordered, Open by value:url
Slices for coding	Σ	0..*	Coding	Code defined by a terminology system Slice: Unordered, Open by value:code, value:system
coding:loincSmokingStatus	Σ	0..1	Coding	LOINC Smoking Status
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations Slice: Unordered, Open by value:url
system	Σ	1..1	uri	Identity of the terminology system Fixed Value: http://loinc.org
version	Σ	0..1	string	Version of the system - if relevant
code	Σ	1..1	code	Symbol in syntax defined by the system Fixed Value: 72166-2
display	Σ	0..1	string	Representation defined by the system
userSelected	Σ	0..1	boolean	If this coding was chosen directly by the user
text	Σ	0..1	string	Plain text representation of the concept
subject	SOΣ	1..1	Reference(AU Core Patient)	Who and/or what the observation is about Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
focus	Σ	0..*	Reference(Resource)	What the observation is about, when it is not about the subject of record
encounter	Σ	0..1	Reference(Encounter)	Healthcare event during which this observation is made
effective[x]	SOΣC	1..1	dateTime	Date, and optionally time, the observation was performed au-core-obs-01: Date shall be at least to day Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
issued	Σ	0..1	instant	Date/Time this version was made available
performer	Σ	0..*	Reference(Practitioner | PractitionerRole | Organization | CareTeam | Patient | RelatedPerson)	Who is responsible for the observation
value[x]	SOΣC	0..1	CodeableConcept	Actual result Binding: Smoking Status (extensible) Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
dataAbsentReason	SOC	0..1	CodeableConcept	Why the result is missing Binding: DataAbsentReason (extensible): Codes specifying why the result (Observation.value[x]) is missing. Obligations Actor SHALL:populate-if-known AU Core Responder SHALL:no-error AU Core Requester
interpretation		0..*	CodeableConcept	High, low, normal, etc. Binding: ObservationInterpretationCodes (extensible): Codes identifying interpretations of observations.
note		0..*	Annotation	Comments about the observation
bodySite		0..1	CodeableConcept	Observed body part Binding: SNOMEDCTBodyStructures (example): Codes describing anatomical locations. May include laterality.
method		0..1	CodeableConcept	How it was done Binding: ObservationMethods (example): Methods for simple observations.
specimen		0..1	Reference(Specimen)	Specimen used for this observation
device		0..1	Reference(Device | DeviceMetric)	(Measurement) Device
referenceRange	C	0..*	BackboneElement	Provides guide for interpretation obs-3: Must have at least a low or a high or text
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
low	C	0..1	SimpleQuantity	Low Range, if relevant
high	C	0..1	SimpleQuantity	High Range, if relevant
type		0..1	CodeableConcept	Reference range qualifier Binding: ObservationReferenceRangeMeaningCodes (preferred): Code for the meaning of a reference range.
appliesTo		0..*	CodeableConcept	Reference range population Binding: ObservationReferenceRangeAppliesToCodes (example): Codes identifying the population the reference range applies to.
age		0..1	Range	Applicable age range, if relevant
text		0..1	string	Text based reference range in an observation
hasMember	Σ	0..*	Reference(Observation | QuestionnaireResponse | MolecularSequence)	Related resource that belongs to the Observation group
derivedFrom	Σ	0..*	Reference(DocumentReference | ImagingStudy | Media | QuestionnaireResponse | Observation | MolecularSequence)	Related measurements the observation is made from
component	Σ	0..*	BackboneElement	Component results
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
code	Σ	1..1	CodeableConcept	Type of component observation (code / type) Binding: LOINCCodes (example): Codes identifying names of simple observations.
value[x]	Σ	0..1		Actual component result
valueQuantity			Quantity
valueCodeableConcept			CodeableConcept
valueString			string
valueBoolean			boolean
valueInteger			integer
valueRange			Range
valueRatio			Ratio
valueSampledData			SampledData
valueTime			time
valueDateTime			dateTime
valuePeriod			Period
dataAbsentReason	C	0..1	CodeableConcept	Why the component result is missing Binding: DataAbsentReason (extensible): Codes specifying why the result (Observation.value[x]) is missing.
interpretation		0..*	CodeableConcept	High, low, normal, etc. Binding: ObservationInterpretationCodes (extensible): Codes identifying interpretations of observations.
referenceRange		0..*	See referenceRange (Observation)	Provides guide for interpretation of component result
Documentation for this format

Terminology Bindings

Path	Conformance	ValueSet / Code	URI
Observation.language	preferred	CommonLanguages Additional Bindings Purpose AllLanguages Max Binding http://hl7.org/fhir/ValueSet/languages from the FHIR Standard
Observation.status	required	ObservationStatus http://hl7.org/fhir/ValueSet/observation-status|4.0.1 from the FHIR Standard
Observation.category	preferred	ObservationCategoryCodes http://hl7.org/fhir/ValueSet/observation-category from the FHIR Standard
Observation.category:socialHistory	preferred	Pattern: social-history http://hl7.org/fhir/ValueSet/observation-category from the FHIR Standard
Observation.code	example	Pattern: SNOMED-CT Code 1747861000168109 http://hl7.org/fhir/ValueSet/observation-codes from the FHIR Standard
Observation.value[x]	extensible	SmokingStatus https://healthterminologies.gov.au/fhir/ValueSet/smoking-status-1 from https://tx.ontoserver.csiro.au/fhir
Observation.dataAbsentReason	extensible	DataAbsentReason http://hl7.org/fhir/ValueSet/data-absent-reason from the FHIR Standard
Observation.interpretation	extensible	ObservationInterpretationCodes http://hl7.org/fhir/ValueSet/observation-interpretation from the FHIR Standard
Observation.bodySite	example	SNOMEDCTBodyStructures http://hl7.org/fhir/ValueSet/body-site from the FHIR Standard
Observation.method	example	ObservationMethods http://hl7.org/fhir/ValueSet/observation-methods from the FHIR Standard
Observation.referenceRange.type	preferred	ObservationReferenceRangeMeaningCodes http://hl7.org/fhir/ValueSet/referencerange-meaning from the FHIR Standard
Observation.referenceRange.appliesTo	example	ObservationReferenceRangeAppliesToCodes http://hl7.org/fhir/ValueSet/referencerange-appliesto from the FHIR Standard
Observation.component.code	example	LOINCCodes (a valid code from LOINC) http://hl7.org/fhir/ValueSet/observation-codes from the FHIR Standard
Observation.component.dataAbsentReason	extensible	DataAbsentReason http://hl7.org/fhir/ValueSet/data-absent-reason from the FHIR Standard
Observation.component.interpretation	extensible	ObservationInterpretationCodes http://hl7.org/fhir/ValueSet/observation-interpretation from the FHIR Standard

Constraints

Id	Grade	Path(s)	Details	Requirements
au-core-obs-01	error	Observation.effective[x]	Date shall be at least to day : $this is DateTime implies $this.toString().length() >= 8
au-core-obs-02	error	Observation	At least value or data absent reason shall be present : dataAbsentReason.exists() or value.exists()
dom-2	error	Observation	If the resource is contained in another resource, it SHALL NOT contain nested Resources : contained.contained.empty()
dom-3	error	Observation	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	Observation	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	Observation	If a resource is contained in another resource, it SHALL NOT have a security label : contained.meta.security.empty()
dom-6	best practice	Observation	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()
obs-3	error	Observation.referenceRange	Must have at least a low or a high or text : low.exists() or high.exists() or text.exists()
obs-6	error	Observation	dataAbsentReason SHALL only be present if Observation.value[x] is not present : dataAbsentReason.empty() or value.empty()
obs-7	error	Observation	If Observation.code is the same as an Observation.component.code then the value element associated with the code SHALL NOT be present : value.empty() or component.code.where(coding.intersect(%resource.code.coding).exists()).empty()

This structure is derived from Observation

Summary

Mandatory: 4 elements(2 nested mandatory elements)
Must-Support: 7 elements
Fixed: 2 elements

Structures

This structure refers to these other structures:

• AU Core Patient (http://hl7.org.au/fhir/core/StructureDefinition/au-core-patient)

Slices

This structure defines the following Slices:

• The element 1 is sliced based on the value of Observation.category
• The element 2 is sliced based on the values of Observation.code.coding

Maturity: 1

Below is an overview of the mandatory and optional search parameters and combined search parameters. See the AU Core CapabilityStatements for a complete list of supported RESTful interactions for this IG.

FHIR search operations are described here and the syntax used to describe AU Core interactions is defined here.

Any search parameter defined in FHIR may be 'allowed' by the system unless explicitly marked as "SHALL NOT". A few items are marked as MAY in this implementation guide to highlight their potential relevance.

Mandatory Search Parameters

The following search parameters and search parameter combinations SHALL be supported:

1. SHALL support searching using the patient search parameter:
   • SHOULD support chained searching of patient canonical identifier patient.identifier (e.g. patient.identifier=[system|][code])

   GET [base]/Observation?patient={Type/}[id] or optionally GET [base]/Observation?patient.identifier=[system|][code]

   Example:

   1. GET [base]/Observation?patient=5678
   2. GET [base]/Observation?patient.identifier=http://ns.electronichealth.net.au/id/medicare-number|32788511952
   3. GET [base]/Observation?patient.identifier=http://ns.electronichealth.net.au/id/hi/ihi/1.0|8003608833357361

   Implementation Notes: Fetches a bundle of all Observation resources for the specified patient (how to search by reference and how to search by token)

2. SHALL support searching using the combination of the patient and category search parameters:
   • SHOULD support chained searching of patient canonical identifier patient.identifier (e.g. patient.identifier=[system|][code])

   GET [base]/Observation?patient={Type/}[id]&category={system|}[code]

   Example:

   1. GET [base]/Observation?patient=5678&category=http://terminology.hl7.org/CodeSystem/observation-category|social-history
   2. GET [base]/Observation?patient.identifier=http://ns.electronichealth.net.au/id/hi/ihi/1.0|8003608833357361&category=http://terminology.hl7.org/CodeSystem/observation-category|social-history

   Implementation Notes: Fetches a bundle of all Observation resources for the specified patient and category (how to search by reference and how to search by token)

3. SHALL support searching using the combination of the patient and category and date search parameters:
   • SHOULD support chained searching of patient canonical identifier patient.identifier (e.g. patient.identifier=[system|][code])
   • SHALL support these date comparators: gt,lt,ge,le
   • SHOULD support multipleAnd search on date (e.g.date=[date]&date=[date]]&...)

   GET [base]/Observation?patient={Type/}[id]&category={system|}[code]&date={gt|lt|ge|le}[date]{&date={gt|lt|ge|le}[date]&...}

   Example:

   1. GET [base]/Observation?patient=5678&category=http://terminology.hl7.org/CodeSystem/observation-category|social-history&date=ge2020-01-01T00:00:00Z

   Implementation Notes: Fetches a bundle of all Observation resources for the specified patient and date and a category code = social-history (how to search by reference and how to search by token and how to search by date)

4. SHALL support searching using the combination of the patient and code search parameters:
   • SHOULD support chained searching of patient canonical identifier patient.identifier (e.g. patient.identifier=[system|][code])
   • SHOULD support multipleOr search on code (e.g.code={system|}[code],{system|}[code],...)

   GET [base]/Observation?patient={Type/}[id]&code={system|}[code]{,{system|}[code],...}

   Example:

   1. GET [base]/Observation?patient=5678&code=http://snomed.info/sct|266918002

   Implementation Notes: Fetches a bundle of all Observation resources for the specified patient and observation code(s). The Observation code parameter searches Observation.code only. (how to search by reference and how to search by token)

Optional Search Parameters:

The following search parameters and search parameter combinations SHOULD be supported:

1. SHOULD support searching using the combination of the patient and category and status search parameters:
   • SHOULD support chained searching of patient canonical identifier patient.identifier (e.g. patient.identifier=[system|][code])
   • SHALL support multipleOr search on status (e.g.status={system|}[code],{system|}[code],...)

   GET [base]/Observation?patient={Type/}[id]&category={system|}[code]&status={system|}[code]{,{system|}[code],...}

   Example:

   1. GET [base]/Observation?patient=5678&category=http://terminology.hl7.org/CodeSystem/observation-category|social-history&status=final

   Implementation Notes: Fetches a bundle of all Observation resources for the specified patient and category and status (how to search by reference and how to search by token)

2. SHOULD support searching using the combination of the patient and code and date search parameters:
   • SHOULD support chained searching of patient canonical identifier patient.identifier (e.g. patient.identifier=[system|][code]
   • SHOULD support multipleOr search on code (e.g.code={system|}[code],{system|}[code],...)
   • SHALL support these date comparators: gt,lt,ge,le
   • SHOULD support multipleAnd search on date (e.g.date=[date]&date=[date]]&...)

   GET [base]/Observation?patient={Type/}[id]&code={system|}[code]{,{system|}[code],...}&date={gt|lt|ge|le}[date]{&date={gt|lt|ge|le}[date]&...}

   Example:

   1. GET [base]/Observation?patient=5678&code=http://snomed.info/sct|266918002&date=ge2020-01-01T00:00:00Z
   2. GET [base]/Observation?patient.identifier=http://example.org/fhir/mrn|12345&code=http://snomed.info/sct|266918002&date=ge2020-01-01T00:00:00Z

   Implementation Notes: Fetches a bundle of all Observation resources for the specified patient and date and observation code(s) (how to search by reference and how to search by token and how to search by date)