Example Usage Scenarios:

The following are example usage scenarios for this profile:

• Query for clinical tests or diagnostic imaging results for a patient.
• Record or update clinical tests or diagnostic imaging results belonging to a Patient

Mandatory and Must Support Data Elements

The following data elements must always be present (Mandatory definition) or must be supported if the data is present in the sending system (Must Support definition). They are presented below in a simple human-readable explanation. Profile-specific guidance and examples are provided as well. The Formal Views below provides the formal summary, definitions, and terminology requirements.

Each Observation Must Have:

1. a status
2. a category code
3. a LOINC code, if available, which tells you what is being measured
4. a patient

Each Observation Must Support:

1. encounter associated with Observation
2. a time indicating when the measurement was taken
3. a result value
   • if the result value is a numeric quantity, a standard UCUM unit
4. a reason why the data is absent*

* see guidance below

Profile Specific Implementation Guidance:

• ServersSHOULD use the base FHIR Observation Category Codes. The Observation.category element provides an efficient way of restricting search on observations to a given context such as procedure, exam or laboratory observations. Example searches are shown in the Quick Start section below. However, clients need to understand that data categorization is somewhat subjective. The categorization applied by the source may not align with the client’s expectations. Clients may find it more useful to use queries based on a specific code or set of codes or to perform additional client side filtering of query results.
• Additional codes that translate or map to the Observation code or category codes are allowed. For example:
  • providing both a local code and LOINC code
  • providing a more specific code, a SNOMED CT concept, or a system-specific code.
• Systems SHOULD support Observation.effectivePeriod to accurately represent procedure tests that are collected over a period of time .
• *An Observation without a value, SHALL include a reason why the data is absent unless there are 1) component observations, or 2) reporting panel observations using Observation.hasMember.
  • For further guidance see the Observation Grouping section in FHIR Specification.
  • Systems that never provide an observation without a value are not required to support Observation.dataAbsentReason.
• *An Observation.component without a value, SHALL include a reason why the data is absent.
  • Systems that never provide a component observation without a component value are not required to support Observation.component.dataAbsentReason.
• See the General Guidance page for further guidance on using SNOMED and UCUM.
• See the LOINC scale type to FHIR data type mapping for guidance on which Observation.value[x] data type to use based on the LOINC Type of Scale.

• For a starter set of example clinical test LOINC codes, see Appendix B in U.S. Core Data for Interoperability (USCDI) Task Force 2021 HITAC Phase 3 Recommendations Report Letter.
• For representing laboratory test results, see the US Core Laboratory Result Observation Profile.

• 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 us-core-2: If there is no component or hasMember element then either a value[x] or a data absent reason must be present
status	S	1..1	code	registered | preliminary | final | amended +
Slices for category	S	1..*	CodeableConcept	Classification of type of observation Slice: Unordered, Open by pattern:$this
category:us-core	S	0..*	CodeableConcept	Classification of type of observation Binding: US Core Clinical Result Observation Category (required): Note that other codes are permitted, see Required Bindings When Slicing by Value Sets
code	S	1..1	CodeableConcept	Clinical Test or Procedure Name Binding: LOINCCodes (extensible)
subject	S	1..1	Reference(US Core Patient Profile S | Group | Device | US Core Location Profile)	Who and/or what the observation is about
encounter	S	0..1	Reference(US Core Encounter Profile)	Encounter associated with Observation
effective[x]	SC	0..1		Clinically relevant time/time-period for observation us-core-1: Datetime must be at least to day.
effectiveDateTime			dateTime S
effectivePeriod			Period
effectiveTiming			Timing
effectiveInstant			instant
value[x]	SC	0..1		Result Value us-core-3: SHALL use UCUM for coded quantity units.
valueQuantity			Quantity S
valueCodeableConcept			CodeableConcept S
valueString			string S
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
Documentation for this format

Terminology Bindings (Differential)

Path	Conformance	ValueSet
Observation.category:us-core	required	USCoreClinicalResultObservationCategory
Observation.code	extensible	LOINCCodes (a valid code from LOINC)

Constraints

Id	Grade	Path(s)	Details	Requirements
us-core-1	error	Observation.effective[x]	Datetime must be at least to day. : $this is dateTime implies $this.toString().length() >= 10
us-core-2	error	Observation	If there is no component or hasMember element then either a value[x] or a data absent reason must be present : (component.empty() and hasMember.empty()) implies (dataAbsentReason.exists() or value.exists())
us-core-3	error	Observation.value[x]	SHALL use UCUM for coded quantity units. : ofType(Quantity).system.empty() or ofType(Quantity).system = 'http://unitsofmeasure.org'

Name	Flags	Card.	Type	Description & Constraints
Observation	C	0..*	Observation	Measurements and simple assertions us-core-2: If there is no component or hasMember element then either a value[x] or a data absent reason must 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	?!SΣ	1..1	code	registered | preliminary | final | amended + Binding: ObservationStatus (required): Codes providing the status of an observation.
Slices for category	S	1..*	CodeableConcept	Classification of type of observation Slice: Unordered, Open by pattern:$this Binding: ObservationCategoryCodes (preferred): Codes for high level observation categories.
category:us-core	S	0..*	CodeableConcept	Classification of type of observation Binding: US Core Clinical Result Observation Category (required): Note that other codes are permitted, see Required Bindings When Slicing by Value Sets
code	SΣ	1..1	CodeableConcept	Clinical Test or Procedure Name Binding: LOINCCodes (extensible)
subject	SΣ	1..1	Reference(US Core Patient Profile)	Who and/or what the observation is about
encounter	SΣ	0..1	Reference(US Core Encounter Profile)	Encounter associated with Observation
effective[x]	SΣC	0..1		Clinically relevant time/time-period for observation us-core-1: Datetime must be at least to day.
effectiveDateTime			dateTime
value[x]	SΣC	0..1		Result Value us-core-3: SHALL use UCUM for coded quantity units.
valueQuantity			Quantity
valueCodeableConcept			CodeableConcept
valueString			string
dataAbsentReason	SC	0..1	CodeableConcept	Why the result is missing Binding: DataAbsentReason (extensible): Codes specifying why the result (Observation.value[x]) is missing.
Documentation for this format

Terminology Bindings

Path	Conformance	ValueSet
Observation.status	required	ObservationStatus
Observation.category	preferred	ObservationCategoryCodes
Observation.category:us-core	required	USCoreClinicalResultObservationCategory
Observation.code	extensible	LOINCCodes (a valid code from LOINC)
Observation.dataAbsentReason	extensible	DataAbsentReason

Constraints

Id	Grade	Path(s)	Details	Requirements
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()
us-core-1	error	Observation.effective[x]	Datetime must be at least to day. : $this is dateTime implies $this.toString().length() >= 10
us-core-2	error	Observation	If there is no component or hasMember element then either a value[x] or a data absent reason must be present : (component.empty() and hasMember.empty()) implies (dataAbsentReason.exists() or value.exists())
us-core-3	error	Observation.value[x]	SHALL use UCUM for coded quantity units. : ofType(Quantity).system.empty() or ofType(Quantity).system = 'http://unitsofmeasure.org'

Name	Flags	Card.	Type	Description & Constraints
Observation	C	0..*	Observation	Measurements and simple assertions us-core-2: If there is no component or hasMember element then either a value[x] or a data absent reason must 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	?!SΣ	1..1	code	registered | preliminary | final | amended + Binding: ObservationStatus (required): Codes providing the status of an observation.
Slices for category	S	1..*	CodeableConcept	Classification of type of observation Slice: Unordered, Open by pattern:$this Binding: ObservationCategoryCodes (preferred): Codes for high level observation categories.
category:us-core	S	0..*	CodeableConcept	Classification of type of observation Binding: US Core Clinical Result Observation Category (required): Note that other codes are permitted, see Required Bindings When Slicing by Value Sets
code	SΣ	1..1	CodeableConcept	Clinical Test or Procedure Name Binding: LOINCCodes (extensible)
subject	SΣ	1..1	Reference(US Core Patient Profile S | Group | Device | US Core Location Profile)	Who and/or what the observation is about
focus	Σ	0..*	Reference(Resource)	What the observation is about, when it is not about the subject of record
encounter	SΣ	0..1	Reference(US Core Encounter Profile)	Encounter associated with Observation
effective[x]	SΣC	0..1		Clinically relevant time/time-period for observation us-core-1: Datetime must be at least to day.
effectiveDateTime			dateTime S
effectivePeriod			Period
effectiveTiming			Timing
effectiveInstant			instant
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]	SΣC	0..1		Result Value us-core-3: SHALL use UCUM for coded quantity units.
valueQuantity			Quantity S
valueCodeableConcept			CodeableConcept S
valueString			string S
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		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
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
Observation.language	preferred	CommonLanguages Additional Bindings Purpose AllLanguages Max Binding
Observation.status	required	ObservationStatus
Observation.category	preferred	ObservationCategoryCodes
Observation.category:us-core	required	USCoreClinicalResultObservationCategory
Observation.code	extensible	LOINCCodes (a valid code from LOINC)
Observation.dataAbsentReason	extensible	DataAbsentReason
Observation.interpretation	extensible	ObservationInterpretationCodes
Observation.bodySite	example	SNOMEDCTBodyStructures
Observation.method	example	ObservationMethods
Observation.referenceRange.type	preferred	ObservationReferenceRangeMeaningCodes
Observation.referenceRange.appliesTo	example	ObservationReferenceRangeAppliesToCodes
Observation.component.code	example	LOINCCodes (a valid code from LOINC)
Observation.component.dataAbsentReason	extensible	DataAbsentReason
Observation.component.interpretation	extensible	ObservationInterpretationCodes

Constraints

Id	Grade	Path(s)	Details	Requirements
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()
us-core-1	error	Observation.effective[x]	Datetime must be at least to day. : $this is dateTime implies $this.toString().length() >= 10
us-core-2	error	Observation	If there is no component or hasMember element then either a value[x] or a data absent reason must be present : (component.empty() and hasMember.empty()) implies (dataAbsentReason.exists() or value.exists())
us-core-3	error	Observation.value[x]	SHALL use UCUM for coded quantity units. : ofType(Quantity).system.empty() or ofType(Quantity).system = 'http://unitsofmeasure.org'

Differential View

This structure is derived from Observation

Name	Flags	Card.	Type	Description & Constraints
Observation	C	0..*	Observation	Measurements and simple assertions us-core-2: If there is no component or hasMember element then either a value[x] or a data absent reason must be present
status	S	1..1	code	registered | preliminary | final | amended +
Slices for category	S	1..*	CodeableConcept	Classification of type of observation Slice: Unordered, Open by pattern:$this
category:us-core	S	0..*	CodeableConcept	Classification of type of observation Binding: US Core Clinical Result Observation Category (required): Note that other codes are permitted, see Required Bindings When Slicing by Value Sets
code	S	1..1	CodeableConcept	Clinical Test or Procedure Name Binding: LOINCCodes (extensible)
subject	S	1..1	Reference(US Core Patient Profile S | Group | Device | US Core Location Profile)	Who and/or what the observation is about
encounter	S	0..1	Reference(US Core Encounter Profile)	Encounter associated with Observation
effective[x]	SC	0..1		Clinically relevant time/time-period for observation us-core-1: Datetime must be at least to day.
effectiveDateTime			dateTime S
effectivePeriod			Period
effectiveTiming			Timing
effectiveInstant			instant
value[x]	SC	0..1		Result Value us-core-3: SHALL use UCUM for coded quantity units.
valueQuantity			Quantity S
valueCodeableConcept			CodeableConcept S
valueString			string S
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
Documentation for this format

Terminology Bindings (Differential)

Path	Conformance	ValueSet
Observation.category:us-core	required	USCoreClinicalResultObservationCategory
Observation.code	extensible	LOINCCodes (a valid code from LOINC)

Constraints

Id	Grade	Path(s)	Details	Requirements
us-core-1	error	Observation.effective[x]	Datetime must be at least to day. : $this is dateTime implies $this.toString().length() >= 10
us-core-2	error	Observation	If there is no component or hasMember element then either a value[x] or a data absent reason must be present : (component.empty() and hasMember.empty()) implies (dataAbsentReason.exists() or value.exists())
us-core-3	error	Observation.value[x]	SHALL use UCUM for coded quantity units. : ofType(Quantity).system.empty() or ofType(Quantity).system = 'http://unitsofmeasure.org'

Key Elements View

Name	Flags	Card.	Type	Description & Constraints
Observation	C	0..*	Observation	Measurements and simple assertions us-core-2: If there is no component or hasMember element then either a value[x] or a data absent reason must 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	?!SΣ	1..1	code	registered | preliminary | final | amended + Binding: ObservationStatus (required): Codes providing the status of an observation.
Slices for category	S	1..*	CodeableConcept	Classification of type of observation Slice: Unordered, Open by pattern:$this Binding: ObservationCategoryCodes (preferred): Codes for high level observation categories.
category:us-core	S	0..*	CodeableConcept	Classification of type of observation Binding: US Core Clinical Result Observation Category (required): Note that other codes are permitted, see Required Bindings When Slicing by Value Sets
code	SΣ	1..1	CodeableConcept	Clinical Test or Procedure Name Binding: LOINCCodes (extensible)
subject	SΣ	1..1	Reference(US Core Patient Profile)	Who and/or what the observation is about
encounter	SΣ	0..1	Reference(US Core Encounter Profile)	Encounter associated with Observation
effective[x]	SΣC	0..1		Clinically relevant time/time-period for observation us-core-1: Datetime must be at least to day.
effectiveDateTime			dateTime
value[x]	SΣC	0..1		Result Value us-core-3: SHALL use UCUM for coded quantity units.
valueQuantity			Quantity
valueCodeableConcept			CodeableConcept
valueString			string
dataAbsentReason	SC	0..1	CodeableConcept	Why the result is missing Binding: DataAbsentReason (extensible): Codes specifying why the result (Observation.value[x]) is missing.
Documentation for this format

Terminology Bindings

Path	Conformance	ValueSet
Observation.status	required	ObservationStatus
Observation.category	preferred	ObservationCategoryCodes
Observation.category:us-core	required	USCoreClinicalResultObservationCategory
Observation.code	extensible	LOINCCodes (a valid code from LOINC)
Observation.dataAbsentReason	extensible	DataAbsentReason

Constraints

Id	Grade	Path(s)	Details	Requirements
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()
us-core-1	error	Observation.effective[x]	Datetime must be at least to day. : $this is dateTime implies $this.toString().length() >= 10
us-core-2	error	Observation	If there is no component or hasMember element then either a value[x] or a data absent reason must be present : (component.empty() and hasMember.empty()) implies (dataAbsentReason.exists() or value.exists())
us-core-3	error	Observation.value[x]	SHALL use UCUM for coded quantity units. : ofType(Quantity).system.empty() or ofType(Quantity).system = 'http://unitsofmeasure.org'

Snapshot View

Name	Flags	Card.	Type	Description & Constraints
Observation	C	0..*	Observation	Measurements and simple assertions us-core-2: If there is no component or hasMember element then either a value[x] or a data absent reason must 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	?!SΣ	1..1	code	registered | preliminary | final | amended + Binding: ObservationStatus (required): Codes providing the status of an observation.
Slices for category	S	1..*	CodeableConcept	Classification of type of observation Slice: Unordered, Open by pattern:$this Binding: ObservationCategoryCodes (preferred): Codes for high level observation categories.
category:us-core	S	0..*	CodeableConcept	Classification of type of observation Binding: US Core Clinical Result Observation Category (required): Note that other codes are permitted, see Required Bindings When Slicing by Value Sets
code	SΣ	1..1	CodeableConcept	Clinical Test or Procedure Name Binding: LOINCCodes (extensible)
subject	SΣ	1..1	Reference(US Core Patient Profile S | Group | Device | US Core Location Profile)	Who and/or what the observation is about
focus	Σ	0..*	Reference(Resource)	What the observation is about, when it is not about the subject of record
encounter	SΣ	0..1	Reference(US Core Encounter Profile)	Encounter associated with Observation
effective[x]	SΣC	0..1		Clinically relevant time/time-period for observation us-core-1: Datetime must be at least to day.
effectiveDateTime			dateTime S
effectivePeriod			Period
effectiveTiming			Timing
effectiveInstant			instant
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]	SΣC	0..1		Result Value us-core-3: SHALL use UCUM for coded quantity units.
valueQuantity			Quantity S
valueCodeableConcept			CodeableConcept S
valueString			string S
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		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
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
Observation.language	preferred	CommonLanguages Additional Bindings Purpose AllLanguages Max Binding
Observation.status	required	ObservationStatus
Observation.category	preferred	ObservationCategoryCodes
Observation.category:us-core	required	USCoreClinicalResultObservationCategory
Observation.code	extensible	LOINCCodes (a valid code from LOINC)
Observation.dataAbsentReason	extensible	DataAbsentReason
Observation.interpretation	extensible	ObservationInterpretationCodes
Observation.bodySite	example	SNOMEDCTBodyStructures
Observation.method	example	ObservationMethods
Observation.referenceRange.type	preferred	ObservationReferenceRangeMeaningCodes
Observation.referenceRange.appliesTo	example	ObservationReferenceRangeAppliesToCodes
Observation.component.code	example	LOINCCodes (a valid code from LOINC)
Observation.component.dataAbsentReason	extensible	DataAbsentReason
Observation.component.interpretation	extensible	ObservationInterpretationCodes

Constraints

Id	Grade	Path(s)	Details	Requirements
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()
us-core-1	error	Observation.effective[x]	Datetime must be at least to day. : $this is dateTime implies $this.toString().length() >= 10
us-core-2	error	Observation	If there is no component or hasMember element then either a value[x] or a data absent reason must be present : (component.empty() and hasMember.empty()) implies (dataAbsentReason.exists() or value.exists())
us-core-3	error	Observation.value[x]	SHALL use UCUM for coded quantity units. : ofType(Quantity).system.empty() or ofType(Quantity).system = 'http://unitsofmeasure.org'

This structure is derived from Observation

Summary

Mandatory: 2 elements
Must-Support: 9 elements

Structures

This structure refers to these other structures:

• US Core Patient Profile (http://hl7.org/fhir/us/core/StructureDefinition/us-core-patient)
• US Core Location Profile (http://hl7.org/fhir/us/core/StructureDefinition/us-core-location)
• US Core Encounter Profile (http://hl7.org/fhir/us/core/StructureDefinition/us-core-encounter)

Slices

This structure defines the following Slices:

• The element Observation.category is sliced based on the value of pattern:$this

Maturity: 3

Quick Start

Below is an overview of the required Server RESTful FHIR interactions for this profile - for example, search and read operations - when supporting the US Core interactions to access this profile’s information (Profile Support + Interaction Support). Note that systems that support only US Core Profiles (Profile Only Support) are not required to support these interactions. See the US Core Server CapabilityStatement for a complete list of supported RESTful interactions for this IG.

• The syntax used to describe the interactions is described here.
• See the General Requirements section for additional rules and expectations when a server requires status parameters.
• See the General Guidance section for additional guidance on searching for multiple patients.

Mandatory Search Parameters:

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

1. SHALL support searching using the combination of the patient and category search parameters:

   GET [base]/Observation?patient={Type/}[id]&category={http://terminology.hl7.org/CodeSystem/observation-category|}procedure

   Example:

   1. GET [base]/Observation?patient=1134281&category=http://terminology.hl7.org/CodeSystem/observation-category|procedure

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

2. SHALL support searching using the combination of the patient and code search parameters:
   • including optional support for OR 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=1134281&code=http://loinc.org|44974-4
   2. GET [base]/Observation?patient=1134281&code=http://loinc.org|44974-4,http://loinc.org|44963-7,http://loinc.org|8601-7

   Implementation Notes: Fetches a bundle of all Observation resources for the specified patient and observation code(s). SHOULD support search by multiple report codes. The Observation code parameter searches `Observation.code only. (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:
   • including support for these date comparators: gt,lt,ge,le
   • including optional support for AND search on date (e.g.date=[date]&date=[date]]&...)

   GET [base]/Observation?patient={Type/}[id]&category={http://terminology.hl7.org/CodeSystem/observation-category|}procedure&date={gt|lt|ge|le}[date]{&date={gt|lt|ge|le}[date]&...}

   Example:

   1. GET [base]Observation?patient=555580&category=http://terminology.hl7.org/CodeSystem/observation-category|procedure&date=ge2018-03-14T00:00:00Z

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

Optional Search Parameters:

The following search parameter combinations SHOULD be supported:

1. SHOULD support searching using the combination of the patient and category and status search parameters:
   • including support for OR search on status (e.g.status={system|}[code],{system|}[code],...)

   GET [base]/Observation?patient={Type/}[id]&category={http://terminology.hl7.org/CodeSystem/observation-category|}procedure&status={system|}[code]{,{system|}[code],...}

   Example:

   1. GET [base]/Observation?patient=1134281&category=http://terminology.hl7.org/CodeSystem/observation-category|procedure&status=final

   Implementation Notes: Fetches a bundle of all Observation resources for the specified patient and category = procedure 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:
   • including optional support for OR search on code (e.g.code={system|}[code],{system|}[code],...)
   • including support for these date comparators: gt,lt,ge,le
   • including optional support for AND 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=555580&code=http://loinc.org|44974-4&date=ge2019-01-01T00:00:00Z

   Implementation Notes: Fetches a bundle of all Observation resources for the specified patient and date and report code(s). SHOULD support search by multiple report codes. (how to search by reference and how to search by token and how to search by date)