Australian Digital Health Agency FHIR Implementation Guide

This profile identifies the additional constraints, extensions, and value sets that build on and extend Observation that are supported.

Where a more specific Observation profile is applicable, e.g. pathology result observation or imaging result observation, an implementation SHALL ensure the resource conforms to that specific profile.

This profile is designed to set an Observation standard for:

• Query for diagnostic examination results for a patient
• Record or update diagnostic examination results belonging to a patient

This profile may be referred to by APIs, which will be listed here when available.

Profile specific 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.
• The Observation resource can represent a result using one or both of a single value with Observation.value, or set of results using either Observation.component.value or Observation.hasMember.
  • Although all are marked as must support, sending systems are not required to support all choices, but they SHALL support at least one of these elements.
  • A receiving or persisting system SHALL support both elements.
• Observation.identifier may contain the same identifier as in the order or report connecting the resources that are related to a single request fulfilment workflow.

Boundaries and relationships

These profiles build on this profile (ADHA Diagnostic Result Observation) to define specific diagnostic results:

• ADHA Imaging Result Observation
• ADHA Pathology Result Observation

• 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	Measurements and simple assertions inv-dh-obs-05: If there is no component or hasMember element then at least value or data absent reason shall be present
identifier	S	0..*	Identifier	Business Identifier for observation
status	S	1..1	code	preliminary | final | amended + Binding: ObservationStatus Result Available (required)
category	S	1..*	CodeableConcept	Classification of type of observation
code	S	1..1	CodeableConcept	Type of observation (code / type)
subject	SC	1..1	Reference(ADHA Core Patient)	Who and/or what the observation is about inv-dh-obs-01: At least reference or a valid identifier shall be present
effective[x]	SC	1..1	dateTime, Period, Timing, instant	Clinically relevant time/time-period for observation inv-dh-obs-07: Date shall be at least to day
performer	SC	1..*	Reference(ADHA Authoring PractitionerRole | ADHA Core Organization | ADHA Core Patient | ADHA Authoring RelatedPerson)	Who is responsible for the observation inv-dh-obs-03: At least reference or display or a valid identifier shall be present
value[x]	SC	0..1	Quantity, CodeableConcept, string, boolean, integer, Range, Ratio, SampledData, time, dateTime, Period	Actual result
dataAbsentReason	SC	0..1	CodeableConcept	Why the result is missing
interpretation	S	0..*	CodeableConcept	High, low, normal, etc.
note	S	0..*	Annotation	Comments about the observation
bodySite	SC	0..1	CodeableConcept	Observed body part Binding: Body Site (extensible) inv-dh-obs-04: If a coded body site is provided, at least one code shall be from SNOMED CT
method	S	0..1	CodeableConcept	How it was done
referenceRange	S	0..*	BackboneElement	Provides guide for interpretation
low	S	0..1	SimpleQuantity	Low Range, if relevant
high	S	0..1	SimpleQuantity	High Range, if relevant
type	S	0..1	CodeableConcept	Reference range qualifier
text	S	0..1	string	Text based reference range in an observation
hasMember	S	0..*	Reference(ADHA Diagnostic Result Observation | ADHA Imaging Result Observation | ADHA Pathology Result Observation)	Individual observations in a group, study, or panel
reference		1..1	string	Literal reference, Relative, internal or absolute URL
component	SC	0..*	BackboneElement	Component results inv-dh-obs-06: The component shall at least have a value or a data absent reason
code	S	1..1	CodeableConcept	Type of component observation (code / type)
value[x]	SC	0..1	Quantity, CodeableConcept, string, boolean, integer, Range, Ratio, SampledData, time, dateTime, Period	Actual component result
dataAbsentReason	SC	0..1	CodeableConcept	Why the component result is missing
Documentation for this format

Terminology Bindings (Differential)

Path	Conformance	ValueSet	URI
Observation.status	required	ObservationStatusResultAvailable https://healthterminologies.gov.au/fhir/ValueSet/observationstatus-result-available-1 from https://tx.ontoserver.csiro.au/fhir
Observation.bodySite	extensible	BodySite https://healthterminologies.gov.au/fhir/ValueSet/body-site-1 from https://tx.ontoserver.csiro.au/fhir

Constraints

Id	Grade	Path(s)	Details	Requirements
inv-dh-obs-01	error	Observation.subject	At least reference or a valid identifier shall be present : reference.exists() or identifier.where(system.count() + value.count() >1).exists()
inv-dh-obs-03	error	Observation.performer	At least reference or display or a valid identifier shall be present : reference.exists() or display.exists() or identifier.where(system.count() + value.count() >1).exists()
inv-dh-obs-04	error	Observation.bodySite	If a coded body site is provided, at least one code shall be from SNOMED CT : coding.exists() implies coding.where(system='http://snomed.info/sct').exists()
inv-dh-obs-05	error	Observation	If there is no component or hasMember element then at least value or data absent reason shall be present : (component.empty() and hasMember.empty()) implies (dataAbsentReason.exists() or value.exists())
inv-dh-obs-06	error	Observation.component	The component shall at least have a value or a data absent reason : value.exists() or dataAbsentReason.exists()
inv-dh-obs-07	error	Observation.effective[x]	Date shall be at least to day : $this is DateTime implies $this.toString().length() >= 10

Name	Flags	Card.	Type	Description & Constraints
Observation	C	0..*	Observation	Measurements and simple assertions dom-2: If the resource is contained in another resource, it SHALL NOT contain nested Resources dom-3: 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 dom-4: If a resource is contained in another resource, it SHALL NOT have a meta.versionId or a meta.lastUpdated dom-5: If a resource is contained in another resource, it SHALL NOT have a security label dom-6: A resource should have narrative for robust management 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 inv-dh-obs-05: If there is no component or hasMember element then 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 ele-1: All FHIR elements must have a @value or children
modifierExtension	?!	0..*	Extension	Extensions that cannot be ignored ele-1: All FHIR elements must have a @value or children ext-1: Must have either extensions or value[x], not both
identifier	SΣ	0..*	Identifier	Business Identifier for observation ele-1: All FHIR elements must have a @value or children
status	?!SΣ	1..1	code	preliminary | final | amended + Binding: ObservationStatus Result Available (required) ele-1: All FHIR elements must have a @value or children
category	S	1..*	CodeableConcept	Classification of type of observation Binding: ObservationCategoryCodes (preferred): Codes for high level observation categories. ele-1: All FHIR elements must have a @value or children
code	SΣ	1..1	CodeableConcept	Type of observation (code / type) Binding: LOINCCodes (example): Codes identifying names of simple observations. ele-1: All FHIR elements must have a @value or children
subject	SΣC	1..1	Reference(ADHA Core Patient)	Who and/or what the observation is about ele-1: All FHIR elements must have a @value or children inv-dh-obs-01: At least reference or a valid identifier shall be present
effective[x]	SΣC	1..1		Clinically relevant time/time-period for observation ele-1: All FHIR elements must have a @value or children inv-dh-obs-07: Date shall be at least to day
effectiveDateTime			dateTime
effectivePeriod			Period
effectiveTiming			Timing
effectiveInstant			instant
performer	SΣC	1..*	Reference(ADHA Authoring PractitionerRole | ADHA Core Organization | ADHA Core Patient | ADHA Authoring RelatedPerson)	Who is responsible for the observation ele-1: All FHIR elements must have a @value or children inv-dh-obs-03: At least reference or display or a valid identifier shall be present
value[x]	SΣC	0..1		Actual result ele-1: All FHIR elements must have a @value or children
valueQuantity			Quantity
valueCodeableConcept			CodeableConcept
valueString			string
valueBoolean			boolean
valueInteger			integer
valueRange			Range
valueRatio			Ratio
valueSampledData			SampledData
valueTime			time
valueDateTime			dateTime
valuePeriod			Period
dataAbsentReason	SC	0..1	CodeableConcept	Why the result is missing Binding: DataAbsentReason (extensible): Codes specifying why the result (Observation.value[x]) is missing. ele-1: All FHIR elements must have a @value or children
interpretation	S	0..*	CodeableConcept	High, low, normal, etc. Binding: ObservationInterpretationCodes (extensible): Codes identifying interpretations of observations. ele-1: All FHIR elements must have a @value or children
note	S	0..*	Annotation	Comments about the observation ele-1: All FHIR elements must have a @value or children
bodySite	SC	0..1	CodeableConcept	Observed body part Binding: Body Site (extensible) ele-1: All FHIR elements must have a @value or children inv-dh-obs-04: If a coded body site is provided, at least one code shall be from SNOMED CT
method	S	0..1	CodeableConcept	How it was done Binding: ObservationMethods (example): Methods for simple observations. ele-1: All FHIR elements must have a @value or children
referenceRange	SC	0..*	BackboneElement	Provides guide for interpretation ele-1: All FHIR elements must have a @value or children obs-3: Must have at least a low or a high or text
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored even if unrecognized ele-1: All FHIR elements must have a @value or children ext-1: Must have either extensions or value[x], not both
low	SC	0..1	SimpleQuantity	Low Range, if relevant ele-1: All FHIR elements must have a @value or children
high	SC	0..1	SimpleQuantity	High Range, if relevant ele-1: All FHIR elements must have a @value or children
type	S	0..1	CodeableConcept	Reference range qualifier Binding: ObservationReferenceRangeMeaningCodes (preferred): Code for the meaning of a reference range. ele-1: All FHIR elements must have a @value or children
text	S	0..1	string	Text based reference range in an observation ele-1: All FHIR elements must have a @value or children
hasMember	SΣ	0..*	Reference(ADHA Diagnostic Result Observation | ADHA Imaging Result Observation | ADHA Pathology Result Observation)	Individual observations in a group, study, or panel ele-1: All FHIR elements must have a @value or children
reference	ΣC	1..1	string	Literal reference, Relative, internal or absolute URL ele-1: All FHIR elements must have a @value or children
component	SΣC	0..*	BackboneElement	Component results ele-1: All FHIR elements must have a @value or children inv-dh-obs-06: The component shall at least have a value or a data absent reason
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored even if unrecognized ele-1: All FHIR elements must have a @value or children ext-1: Must have either extensions or value[x], not both
code	SΣ	1..1	CodeableConcept	Type of component observation (code / type) Binding: LOINCCodes (example): Codes identifying names of simple observations. ele-1: All FHIR elements must have a @value or children
value[x]	SΣC	0..1		Actual component result ele-1: All FHIR elements must have a @value or children
valueQuantity			Quantity
valueCodeableConcept			CodeableConcept
valueString			string
valueBoolean			boolean
valueInteger			integer
valueRange			Range
valueRatio			Ratio
valueSampledData			SampledData
valueTime			time
valueDateTime			dateTime
valuePeriod			Period
dataAbsentReason	SC	0..1	CodeableConcept	Why the component result is missing Binding: DataAbsentReason (extensible): Codes specifying why the result (Observation.value[x]) is missing. ele-1: All FHIR elements must have a @value or children
Documentation for this format

Terminology Bindings

Path	Conformance	ValueSet	URI
Observation.status	required	ObservationStatusResultAvailable https://healthterminologies.gov.au/fhir/ValueSet/observationstatus-result-available-1 from https://tx.ontoserver.csiro.au/fhir
Observation.category	preferred	ObservationCategoryCodes http://hl7.org/fhir/ValueSet/observation-category from the FHIR Standard
Observation.code	example	LOINCCodes (a valid code from LOINC) http://hl7.org/fhir/ValueSet/observation-codes from the FHIR Standard
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	extensible	BodySite https://healthterminologies.gov.au/fhir/ValueSet/body-site-1 from https://tx.ontoserver.csiro.au/fhir
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.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

Constraints

Id	Grade	Path(s)	Details	Requirements
inv-dh-obs-01	error	Observation.subject	At least reference or a valid identifier shall be present : reference.exists() or identifier.where(system.count() + value.count() >1).exists()
inv-dh-obs-03	error	Observation.performer	At least reference or display or a valid identifier shall be present : reference.exists() or display.exists() or identifier.where(system.count() + value.count() >1).exists()
inv-dh-obs-04	error	Observation.bodySite	If a coded body site is provided, at least one code shall be from SNOMED CT : coding.exists() implies coding.where(system='http://snomed.info/sct').exists()
inv-dh-obs-05	error	Observation	If there is no component or hasMember element then at least value or data absent reason shall be present : (component.empty() and hasMember.empty()) implies (dataAbsentReason.exists() or value.exists())
inv-dh-obs-06	error	Observation.component	The component shall at least have a value or a data absent reason : value.exists() or dataAbsentReason.exists()
inv-dh-obs-07	error	Observation.effective[x]	Date shall be at least to day : $this is DateTime implies $this.toString().length() >= 10

Name	Flags	Card.	Type	Description & Constraints
Observation	C	0..*	Observation	Measurements and simple assertions 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 inv-dh-obs-05: If there is no component or hasMember element then 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	SΣ	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	?!SΣ	1..1	code	preliminary | final | amended + Binding: ObservationStatus Result Available (required)
category	S	1..*	CodeableConcept	Classification of type of observation Binding: ObservationCategoryCodes (preferred): Codes for high level observation categories.
code	SΣ	1..1	CodeableConcept	Type of observation (code / type) Binding: LOINCCodes (example): Codes identifying names of simple observations.
subject	SΣC	1..1	Reference(ADHA Core Patient)	Who and/or what the observation is about inv-dh-obs-01: At least reference or a valid identifier shall be present
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]	SΣC	1..1		Clinically relevant time/time-period for observation inv-dh-obs-07: Date shall be at least to day
effectiveDateTime			dateTime
effectivePeriod			Period
effectiveTiming			Timing
effectiveInstant			instant
issued	Σ	0..1	instant	Date/Time this version was made available
performer	SΣC	1..*	Reference(ADHA Authoring PractitionerRole | ADHA Core Organization | ADHA Core Patient | ADHA Authoring RelatedPerson)	Who is responsible for the observation inv-dh-obs-03: At least reference or display or a valid identifier shall be present
value[x]	SΣC	0..1		Actual result
valueQuantity			Quantity
valueCodeableConcept			CodeableConcept
valueString			string
valueBoolean			boolean
valueInteger			integer
valueRange			Range
valueRatio			Ratio
valueSampledData			SampledData
valueTime			time
valueDateTime			dateTime
valuePeriod			Period
dataAbsentReason	SC	0..1	CodeableConcept	Why the result is missing Binding: DataAbsentReason (extensible): Codes specifying why the result (Observation.value[x]) is missing.
interpretation	S	0..*	CodeableConcept	High, low, normal, etc. Binding: ObservationInterpretationCodes (extensible): Codes identifying interpretations of observations.
note	S	0..*	Annotation	Comments about the observation
bodySite	SC	0..1	CodeableConcept	Observed body part Binding: Body Site (extensible) inv-dh-obs-04: If a coded body site is provided, at least one code shall be from SNOMED CT
method	S	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	SC	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	SC	0..1	SimpleQuantity	Low Range, if relevant
high	SC	0..1	SimpleQuantity	High Range, if relevant
type	S	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	S	0..1	string	Text based reference range in an observation
hasMember	SΣ	0..*	Reference(ADHA Diagnostic Result Observation | ADHA Imaging Result Observation | ADHA Pathology Result Observation)	Individual observations in a group, study, or panel
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations Slice: Unordered, Open by value:url
reference	ΣC	1..1	string	Literal reference, Relative, internal or absolute URL
type	Σ	0..1	uri	Type the reference refers to (e.g. "Patient") Binding: ResourceType (extensible): Aa resource (or, for logical models, the URI of the logical model).
identifier	Σ	0..1	Identifier	Logical reference, when literal reference is not known
display	Σ	0..1	string	Text alternative for the resource
derivedFrom	Σ	0..*	Reference(DocumentReference | ImagingStudy | Media | QuestionnaireResponse | Observation | MolecularSequence)	Related measurements the observation is made from
component	SΣC	0..*	BackboneElement	Component results inv-dh-obs-06: The component shall at least have a value or a data absent reason
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	SΣ	1..1	CodeableConcept	Type of component observation (code / type) Binding: LOINCCodes (example): Codes identifying names of simple observations.
value[x]	SΣC	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	SC	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	URI
Observation.language	preferred	CommonLanguages http://hl7.org/fhir/ValueSet/languages from the FHIR Standard Additional Bindings Purpose AllLanguages Max Binding
Observation.status	required	ObservationStatusResultAvailable https://healthterminologies.gov.au/fhir/ValueSet/observationstatus-result-available-1 from https://tx.ontoserver.csiro.au/fhir
Observation.category	preferred	ObservationCategoryCodes http://hl7.org/fhir/ValueSet/observation-category from the FHIR Standard
Observation.code	example	LOINCCodes (a valid code from LOINC) http://hl7.org/fhir/ValueSet/observation-codes from the FHIR Standard
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	extensible	BodySite https://healthterminologies.gov.au/fhir/ValueSet/body-site-1 from https://tx.ontoserver.csiro.au/fhir
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.hasMember.type	extensible	ResourceType http://hl7.org/fhir/ValueSet/resource-types 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
inv-dh-obs-01	error	Observation.subject	At least reference or a valid identifier shall be present : reference.exists() or identifier.where(system.count() + value.count() >1).exists()
inv-dh-obs-03	error	Observation.performer	At least reference or display or a valid identifier shall be present : reference.exists() or display.exists() or identifier.where(system.count() + value.count() >1).exists()
inv-dh-obs-04	error	Observation.bodySite	If a coded body site is provided, at least one code shall be from SNOMED CT : coding.exists() implies coding.where(system='http://snomed.info/sct').exists()
inv-dh-obs-05	error	Observation	If there is no component or hasMember element then at least value or data absent reason shall be present : (component.empty() and hasMember.empty()) implies (dataAbsentReason.exists() or value.exists())
inv-dh-obs-06	error	Observation.component	The component shall at least have a value or a data absent reason : value.exists() or dataAbsentReason.exists()
inv-dh-obs-07	error	Observation.effective[x]	Date shall be at least to day : $this is DateTime implies $this.toString().length() >= 10

Differential View

This structure is derived from Observation

Name	Flags	Card.	Type	Description & Constraints
Observation	C	0..*	Observation	Measurements and simple assertions inv-dh-obs-05: If there is no component or hasMember element then at least value or data absent reason shall be present
identifier	S	0..*	Identifier	Business Identifier for observation
status	S	1..1	code	preliminary | final | amended + Binding: ObservationStatus Result Available (required)
category	S	1..*	CodeableConcept	Classification of type of observation
code	S	1..1	CodeableConcept	Type of observation (code / type)
subject	SC	1..1	Reference(ADHA Core Patient)	Who and/or what the observation is about inv-dh-obs-01: At least reference or a valid identifier shall be present
effective[x]	SC	1..1	dateTime, Period, Timing, instant	Clinically relevant time/time-period for observation inv-dh-obs-07: Date shall be at least to day
performer	SC	1..*	Reference(ADHA Authoring PractitionerRole | ADHA Core Organization | ADHA Core Patient | ADHA Authoring RelatedPerson)	Who is responsible for the observation inv-dh-obs-03: At least reference or display or a valid identifier shall be present
value[x]	SC	0..1	Quantity, CodeableConcept, string, boolean, integer, Range, Ratio, SampledData, time, dateTime, Period	Actual result
dataAbsentReason	SC	0..1	CodeableConcept	Why the result is missing
interpretation	S	0..*	CodeableConcept	High, low, normal, etc.
note	S	0..*	Annotation	Comments about the observation
bodySite	SC	0..1	CodeableConcept	Observed body part Binding: Body Site (extensible) inv-dh-obs-04: If a coded body site is provided, at least one code shall be from SNOMED CT
method	S	0..1	CodeableConcept	How it was done
referenceRange	S	0..*	BackboneElement	Provides guide for interpretation
low	S	0..1	SimpleQuantity	Low Range, if relevant
high	S	0..1	SimpleQuantity	High Range, if relevant
type	S	0..1	CodeableConcept	Reference range qualifier
text	S	0..1	string	Text based reference range in an observation
hasMember	S	0..*	Reference(ADHA Diagnostic Result Observation | ADHA Imaging Result Observation | ADHA Pathology Result Observation)	Individual observations in a group, study, or panel
reference		1..1	string	Literal reference, Relative, internal or absolute URL
component	SC	0..*	BackboneElement	Component results inv-dh-obs-06: The component shall at least have a value or a data absent reason
code	S	1..1	CodeableConcept	Type of component observation (code / type)
value[x]	SC	0..1	Quantity, CodeableConcept, string, boolean, integer, Range, Ratio, SampledData, time, dateTime, Period	Actual component result
dataAbsentReason	SC	0..1	CodeableConcept	Why the component result is missing
Documentation for this format

Terminology Bindings (Differential)

Path	Conformance	ValueSet	URI
Observation.status	required	ObservationStatusResultAvailable https://healthterminologies.gov.au/fhir/ValueSet/observationstatus-result-available-1 from https://tx.ontoserver.csiro.au/fhir
Observation.bodySite	extensible	BodySite https://healthterminologies.gov.au/fhir/ValueSet/body-site-1 from https://tx.ontoserver.csiro.au/fhir

Constraints

Id	Grade	Path(s)	Details	Requirements
inv-dh-obs-01	error	Observation.subject	At least reference or a valid identifier shall be present : reference.exists() or identifier.where(system.count() + value.count() >1).exists()
inv-dh-obs-03	error	Observation.performer	At least reference or display or a valid identifier shall be present : reference.exists() or display.exists() or identifier.where(system.count() + value.count() >1).exists()
inv-dh-obs-04	error	Observation.bodySite	If a coded body site is provided, at least one code shall be from SNOMED CT : coding.exists() implies coding.where(system='http://snomed.info/sct').exists()
inv-dh-obs-05	error	Observation	If there is no component or hasMember element then at least value or data absent reason shall be present : (component.empty() and hasMember.empty()) implies (dataAbsentReason.exists() or value.exists())
inv-dh-obs-06	error	Observation.component	The component shall at least have a value or a data absent reason : value.exists() or dataAbsentReason.exists()
inv-dh-obs-07	error	Observation.effective[x]	Date shall be at least to day : $this is DateTime implies $this.toString().length() >= 10

Key Elements View

Name	Flags	Card.	Type	Description & Constraints
Observation	C	0..*	Observation	Measurements and simple assertions dom-2: If the resource is contained in another resource, it SHALL NOT contain nested Resources dom-3: 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 dom-4: If a resource is contained in another resource, it SHALL NOT have a meta.versionId or a meta.lastUpdated dom-5: If a resource is contained in another resource, it SHALL NOT have a security label dom-6: A resource should have narrative for robust management 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 inv-dh-obs-05: If there is no component or hasMember element then 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 ele-1: All FHIR elements must have a @value or children
modifierExtension	?!	0..*	Extension	Extensions that cannot be ignored ele-1: All FHIR elements must have a @value or children ext-1: Must have either extensions or value[x], not both
identifier	SΣ	0..*	Identifier	Business Identifier for observation ele-1: All FHIR elements must have a @value or children
status	?!SΣ	1..1	code	preliminary | final | amended + Binding: ObservationStatus Result Available (required) ele-1: All FHIR elements must have a @value or children
category	S	1..*	CodeableConcept	Classification of type of observation Binding: ObservationCategoryCodes (preferred): Codes for high level observation categories. ele-1: All FHIR elements must have a @value or children
code	SΣ	1..1	CodeableConcept	Type of observation (code / type) Binding: LOINCCodes (example): Codes identifying names of simple observations. ele-1: All FHIR elements must have a @value or children
subject	SΣC	1..1	Reference(ADHA Core Patient)	Who and/or what the observation is about ele-1: All FHIR elements must have a @value or children inv-dh-obs-01: At least reference or a valid identifier shall be present
effective[x]	SΣC	1..1		Clinically relevant time/time-period for observation ele-1: All FHIR elements must have a @value or children inv-dh-obs-07: Date shall be at least to day
effectiveDateTime			dateTime
effectivePeriod			Period
effectiveTiming			Timing
effectiveInstant			instant
performer	SΣC	1..*	Reference(ADHA Authoring PractitionerRole | ADHA Core Organization | ADHA Core Patient | ADHA Authoring RelatedPerson)	Who is responsible for the observation ele-1: All FHIR elements must have a @value or children inv-dh-obs-03: At least reference or display or a valid identifier shall be present
value[x]	SΣC	0..1		Actual result ele-1: All FHIR elements must have a @value or children
valueQuantity			Quantity
valueCodeableConcept			CodeableConcept
valueString			string
valueBoolean			boolean
valueInteger			integer
valueRange			Range
valueRatio			Ratio
valueSampledData			SampledData
valueTime			time
valueDateTime			dateTime
valuePeriod			Period
dataAbsentReason	SC	0..1	CodeableConcept	Why the result is missing Binding: DataAbsentReason (extensible): Codes specifying why the result (Observation.value[x]) is missing. ele-1: All FHIR elements must have a @value or children
interpretation	S	0..*	CodeableConcept	High, low, normal, etc. Binding: ObservationInterpretationCodes (extensible): Codes identifying interpretations of observations. ele-1: All FHIR elements must have a @value or children
note	S	0..*	Annotation	Comments about the observation ele-1: All FHIR elements must have a @value or children
bodySite	SC	0..1	CodeableConcept	Observed body part Binding: Body Site (extensible) ele-1: All FHIR elements must have a @value or children inv-dh-obs-04: If a coded body site is provided, at least one code shall be from SNOMED CT
method	S	0..1	CodeableConcept	How it was done Binding: ObservationMethods (example): Methods for simple observations. ele-1: All FHIR elements must have a @value or children
referenceRange	SC	0..*	BackboneElement	Provides guide for interpretation ele-1: All FHIR elements must have a @value or children obs-3: Must have at least a low or a high or text
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored even if unrecognized ele-1: All FHIR elements must have a @value or children ext-1: Must have either extensions or value[x], not both
low	SC	0..1	SimpleQuantity	Low Range, if relevant ele-1: All FHIR elements must have a @value or children
high	SC	0..1	SimpleQuantity	High Range, if relevant ele-1: All FHIR elements must have a @value or children
type	S	0..1	CodeableConcept	Reference range qualifier Binding: ObservationReferenceRangeMeaningCodes (preferred): Code for the meaning of a reference range. ele-1: All FHIR elements must have a @value or children
text	S	0..1	string	Text based reference range in an observation ele-1: All FHIR elements must have a @value or children
hasMember	SΣ	0..*	Reference(ADHA Diagnostic Result Observation | ADHA Imaging Result Observation | ADHA Pathology Result Observation)	Individual observations in a group, study, or panel ele-1: All FHIR elements must have a @value or children
reference	ΣC	1..1	string	Literal reference, Relative, internal or absolute URL ele-1: All FHIR elements must have a @value or children
component	SΣC	0..*	BackboneElement	Component results ele-1: All FHIR elements must have a @value or children inv-dh-obs-06: The component shall at least have a value or a data absent reason
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored even if unrecognized ele-1: All FHIR elements must have a @value or children ext-1: Must have either extensions or value[x], not both
code	SΣ	1..1	CodeableConcept	Type of component observation (code / type) Binding: LOINCCodes (example): Codes identifying names of simple observations. ele-1: All FHIR elements must have a @value or children
value[x]	SΣC	0..1		Actual component result ele-1: All FHIR elements must have a @value or children
valueQuantity			Quantity
valueCodeableConcept			CodeableConcept
valueString			string
valueBoolean			boolean
valueInteger			integer
valueRange			Range
valueRatio			Ratio
valueSampledData			SampledData
valueTime			time
valueDateTime			dateTime
valuePeriod			Period
dataAbsentReason	SC	0..1	CodeableConcept	Why the component result is missing Binding: DataAbsentReason (extensible): Codes specifying why the result (Observation.value[x]) is missing. ele-1: All FHIR elements must have a @value or children
Documentation for this format

Terminology Bindings

Path	Conformance	ValueSet	URI
Observation.status	required	ObservationStatusResultAvailable https://healthterminologies.gov.au/fhir/ValueSet/observationstatus-result-available-1 from https://tx.ontoserver.csiro.au/fhir
Observation.category	preferred	ObservationCategoryCodes http://hl7.org/fhir/ValueSet/observation-category from the FHIR Standard
Observation.code	example	LOINCCodes (a valid code from LOINC) http://hl7.org/fhir/ValueSet/observation-codes from the FHIR Standard
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	extensible	BodySite https://healthterminologies.gov.au/fhir/ValueSet/body-site-1 from https://tx.ontoserver.csiro.au/fhir
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.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

Constraints

Id	Grade	Path(s)	Details	Requirements
inv-dh-obs-01	error	Observation.subject	At least reference or a valid identifier shall be present : reference.exists() or identifier.where(system.count() + value.count() >1).exists()
inv-dh-obs-03	error	Observation.performer	At least reference or display or a valid identifier shall be present : reference.exists() or display.exists() or identifier.where(system.count() + value.count() >1).exists()
inv-dh-obs-04	error	Observation.bodySite	If a coded body site is provided, at least one code shall be from SNOMED CT : coding.exists() implies coding.where(system='http://snomed.info/sct').exists()
inv-dh-obs-05	error	Observation	If there is no component or hasMember element then at least value or data absent reason shall be present : (component.empty() and hasMember.empty()) implies (dataAbsentReason.exists() or value.exists())
inv-dh-obs-06	error	Observation.component	The component shall at least have a value or a data absent reason : value.exists() or dataAbsentReason.exists()
inv-dh-obs-07	error	Observation.effective[x]	Date shall be at least to day : $this is DateTime implies $this.toString().length() >= 10

Snapshot View

Name	Flags	Card.	Type	Description & Constraints
Observation	C	0..*	Observation	Measurements and simple assertions 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 inv-dh-obs-05: If there is no component or hasMember element then 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	SΣ	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	?!SΣ	1..1	code	preliminary | final | amended + Binding: ObservationStatus Result Available (required)
category	S	1..*	CodeableConcept	Classification of type of observation Binding: ObservationCategoryCodes (preferred): Codes for high level observation categories.
code	SΣ	1..1	CodeableConcept	Type of observation (code / type) Binding: LOINCCodes (example): Codes identifying names of simple observations.
subject	SΣC	1..1	Reference(ADHA Core Patient)	Who and/or what the observation is about inv-dh-obs-01: At least reference or a valid identifier shall be present
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]	SΣC	1..1		Clinically relevant time/time-period for observation inv-dh-obs-07: Date shall be at least to day
effectiveDateTime			dateTime
effectivePeriod			Period
effectiveTiming			Timing
effectiveInstant			instant
issued	Σ	0..1	instant	Date/Time this version was made available
performer	SΣC	1..*	Reference(ADHA Authoring PractitionerRole | ADHA Core Organization | ADHA Core Patient | ADHA Authoring RelatedPerson)	Who is responsible for the observation inv-dh-obs-03: At least reference or display or a valid identifier shall be present
value[x]	SΣC	0..1		Actual result
valueQuantity			Quantity
valueCodeableConcept			CodeableConcept
valueString			string
valueBoolean			boolean
valueInteger			integer
valueRange			Range
valueRatio			Ratio
valueSampledData			SampledData
valueTime			time
valueDateTime			dateTime
valuePeriod			Period
dataAbsentReason	SC	0..1	CodeableConcept	Why the result is missing Binding: DataAbsentReason (extensible): Codes specifying why the result (Observation.value[x]) is missing.
interpretation	S	0..*	CodeableConcept	High, low, normal, etc. Binding: ObservationInterpretationCodes (extensible): Codes identifying interpretations of observations.
note	S	0..*	Annotation	Comments about the observation
bodySite	SC	0..1	CodeableConcept	Observed body part Binding: Body Site (extensible) inv-dh-obs-04: If a coded body site is provided, at least one code shall be from SNOMED CT
method	S	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	SC	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	SC	0..1	SimpleQuantity	Low Range, if relevant
high	SC	0..1	SimpleQuantity	High Range, if relevant
type	S	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	S	0..1	string	Text based reference range in an observation
hasMember	SΣ	0..*	Reference(ADHA Diagnostic Result Observation | ADHA Imaging Result Observation | ADHA Pathology Result Observation)	Individual observations in a group, study, or panel
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations Slice: Unordered, Open by value:url
reference	ΣC	1..1	string	Literal reference, Relative, internal or absolute URL
type	Σ	0..1	uri	Type the reference refers to (e.g. "Patient") Binding: ResourceType (extensible): Aa resource (or, for logical models, the URI of the logical model).
identifier	Σ	0..1	Identifier	Logical reference, when literal reference is not known
display	Σ	0..1	string	Text alternative for the resource
derivedFrom	Σ	0..*	Reference(DocumentReference | ImagingStudy | Media | QuestionnaireResponse | Observation | MolecularSequence)	Related measurements the observation is made from
component	SΣC	0..*	BackboneElement	Component results inv-dh-obs-06: The component shall at least have a value or a data absent reason
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	SΣ	1..1	CodeableConcept	Type of component observation (code / type) Binding: LOINCCodes (example): Codes identifying names of simple observations.
value[x]	SΣC	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	SC	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	URI
Observation.language	preferred	CommonLanguages http://hl7.org/fhir/ValueSet/languages from the FHIR Standard Additional Bindings Purpose AllLanguages Max Binding
Observation.status	required	ObservationStatusResultAvailable https://healthterminologies.gov.au/fhir/ValueSet/observationstatus-result-available-1 from https://tx.ontoserver.csiro.au/fhir
Observation.category	preferred	ObservationCategoryCodes http://hl7.org/fhir/ValueSet/observation-category from the FHIR Standard
Observation.code	example	LOINCCodes (a valid code from LOINC) http://hl7.org/fhir/ValueSet/observation-codes from the FHIR Standard
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	extensible	BodySite https://healthterminologies.gov.au/fhir/ValueSet/body-site-1 from https://tx.ontoserver.csiro.au/fhir
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.hasMember.type	extensible	ResourceType http://hl7.org/fhir/ValueSet/resource-types 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
inv-dh-obs-01	error	Observation.subject	At least reference or a valid identifier shall be present : reference.exists() or identifier.where(system.count() + value.count() >1).exists()
inv-dh-obs-03	error	Observation.performer	At least reference or display or a valid identifier shall be present : reference.exists() or display.exists() or identifier.where(system.count() + value.count() >1).exists()
inv-dh-obs-04	error	Observation.bodySite	If a coded body site is provided, at least one code shall be from SNOMED CT : coding.exists() implies coding.where(system='http://snomed.info/sct').exists()
inv-dh-obs-05	error	Observation	If there is no component or hasMember element then at least value or data absent reason shall be present : (component.empty() and hasMember.empty()) implies (dataAbsentReason.exists() or value.exists())
inv-dh-obs-06	error	Observation.component	The component shall at least have a value or a data absent reason : value.exists() or dataAbsentReason.exists()
inv-dh-obs-07	error	Observation.effective[x]	Date shall be at least to day : $this is DateTime implies $this.toString().length() >= 10

This structure is derived from Observation

Summary

Mandatory: 4 elements(1 nested mandatory element)
Must-Support: 23 elements

Structures

This structure refers to these other structures:

• ADHA Core Patient (http://ns.electronichealth.net.au/fhir/StructureDefinition/dh-patient-core-1)
• ADHA Authoring PractitionerRole (http://ns.electronichealth.net.au/fhir/StructureDefinition/dh-practitionerrole-author-1)
• ADHA Core Organization (http://ns.electronichealth.net.au/fhir/StructureDefinition/dh-organization-core-1)
• ADHA Authoring RelatedPerson (http://ns.electronichealth.net.au/fhir/StructureDefinition/dh-relatedperson-author-1)
• ADHA Diagnostic Result Observation (http://ns.electronichealth.net.au/fhir/StructureDefinition/dh-observation-diagnosticresult-1)
• ADHA Imaging Result Observation (http://ns.electronichealth.net.au/fhir/StructureDefinition/dh-observation-diagnosticresult-imag-1)
• ADHA Pathology Result Observation (http://ns.electronichealth.net.au/fhir/StructureDefinition/dh-observation-diagnosticresult-path-1)

Below is an overview of the mandatory and optional search parameters. FHIR search operations and the syntax used to describe the interactions is described here.

Mandatory Search Parameters

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

1. SHALL support searching for all allergies for a patient using the subject:identifier search parameter:

   GET [base]/Observation?subject:identifier={system|}[code]

   Example:

   1. GET [base]/Observation?subject:identifier=http://ns.electronichealth.net.au/id/hi/ihi/1.0

      8003608000228437

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

2. SHALL support searching using the combination subject:identifier and category search parameter:

   GET [base]/Observation?subject:identifier={system|}[code]&category[code]

   Example:

   1. GET [base]/Observation?subject:identifier=http://ns.electronichealth.net.au/id/hi/ihi/1.0

      8003608000228437&category=http://terminology.hl7.org/CodeSystem/observation-category

      procedure

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

3. SHALL support searching using the combination subject:identifier and code search parameter:

   GET [base]/Observation?subject:identifier={system|}[code]&code={system|}[code]

   Example:

   1. GET [base]/Observation?subject:identifier=http://ns.electronichealth.net.au/id/hi/ihi/1.0

      8003608000228437&code=http://loinc.org

      90568-7

   Implementation Notes: Fetches a bundle of all Observation resources with the code of an 90568-7 (Polysomnography panel) for the specified patient (how to search by :identifier and how to search by token)

4. SHOULD support searching using the combination of the subject:identifier and date search parameters:

   GET [base]/Observation?subject:identifier={system|}[code]&date=[date]

   Example:

   1. GET [base]/Observation?subject:identifier=http://ns.electronichealth.net.au/id/hi/ihi/1.0

      8003608000228437&date=ge2010-01-01&date=le2011-12-31

   Implementation Notes: Fetches a bundle of all Observation resources for the specified patient that have a date greater than or equal to 1st Jan 2010, a date less than or equal to 31st Dec 2011. (how to search by :identifier and how to search by date)