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

This profile is designed to set an Observation standard for:

• TBD

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

This content will be taken for discussion with HL7 Australia and may be removed or changed.

Profile specific guidance

Whether the measured vision is corrected or uncorrected should be recorded in the observation code.

The use of a pinhole occluder should be recorded as an additional coding in observation code.

The eye or eyes whose vision is measured should be recorded as a body site.

The type of chart used should be recorded as a device type.

Results in Snellen notation should be recorded as ratios, see example Distance visual acuity, both eyes, as a ratio.

Results in N-point notation should be recorded as quantities, see example Near visual acuity, right eye, in N-point notation.

Results of low vision should be recorded as coded terms, see example Distance visual acuity, left eye, as a code.

Undefined terminology resources include:

• for category, a code for a category of "Vision"
• for code, a value set containing the SNOMED CT codes for types of visual acuity test
• for code, SNOMED CT codes for distance visual acuity, corrected; distance visual acuity, uncorrected; near visual acuity, corrected; near visual acuity, uncorrected
• for valueCodeableConcept, a value set containing the SNOMED CT codes for low vision results
• for valueQuantity, a code for unit of measurement for LogMAR notation
• for valueQuantity, a code for unit of measurement for N-point notation
• for valueQuantity, a code for unit of measurement for M-size notation
• for bodySite, a value set containing the SNOMED CT codes for left, right and both eyes.
• for method, a value set containing the SNOMED CT codes for the types of chart commonly used in Australia.

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

This structure is derived from Observation

Name	Flags	Card.	Type	Description & Constraints
Observation		0..*	Observation	Sharpness or acuteness of vision
status		1..1	code	registered | preliminary | final | amended + Fixed Value: final
Slices for category		2..*	CodeableConcept	Classification of type of observation Slice: Unordered, Open by pattern:$this
category:exam		1..1	CodeableConcept	Classification of type of observation Required Pattern: At least the following
coding		1..*	Coding	Code defined by a terminology system Fixed Value: (complex)
system		1..1	uri	Identity of the terminology system Fixed Value: http://terminology.hl7.org/CodeSystem/observation-category
code		1..1	code	Symbol in syntax defined by the system Fixed Value: exam
code		1..1	CodeableConcept	Type of observation (code / type) Binding: http://snomed.info/sct?fhir_vs (preferred): Visual Acuity Test
subject		1..1	Reference(Patient)	Who and/or what the observation is about
effective[x]		1..1	dateTime	Clinically relevant time/time-period for observation
value[x]		0..1		Actual result
valueRatio			Ratio
valueQuantity			Quantity
valueCodeableConcept			CodeableConcept
Slices for value[x]				Content/Rules for all slices
value[x]:valueRatio	C	0..1	Ratio	Visual acuity expressed as a Snellen fraction inv-dh-va-01: Value shall include numerator value and denominator value
value[x]:valueQuantity	C	0..1	Quantity	Visual acuity expressed as a simple quantity inv-dh-va-02: Value shall include value and unit
value[x]:valueCodeableConcept		0..1	CodeableConcept	Visual acuity expressed as a code
method		0..1	CodeableConcept	Method used to measure visual acuity
device		0..1	Reference(Device | DeviceMetric)	Type of chart used to measure visual acuity
Documentation for this format

Terminology Bindings (Differential)

Path	Conformance	ValueSet	URI
Observation.code	preferred	http://snomed.info/sct?fhir_vs http://snomed.info/sct?fhir_vs

Constraints

Id	Grade	Path(s)	Details	Requirements
inv-dh-va-01	error	Observation.value[x]:valueRatio	Value shall include numerator value and denominator value : numerator.value.exists() and denominator.value.exists()
inv-dh-va-02	error	Observation.value[x]:valueQuantity	Value shall include value and unit : value.exists() and unit.exists()

Name	Flags	Card.	Type	Description & Constraints
Observation	C	0..*	Observation	Sharpness or acuteness of vision 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
implicitRules	?!Σ	0..1	uri	A set of rules under which this content was created
modifierExtension	?!	0..*	Extension	Extensions that cannot be ignored
status	?!Σ	1..1	code	registered | preliminary | final | amended + Binding: ObservationStatus (required): Codes providing the status of an observation. Fixed Value: final
Slices for category		2..*	CodeableConcept	Classification of type of observation Slice: Unordered, Open by pattern:$this Binding: ObservationCategoryCodes (preferred): Codes for high level observation categories.
category:exam		1..1	CodeableConcept	Classification of type of observation Binding: ObservationCategoryCodes (preferred): Codes for high level observation categories. Required Pattern: At least the following
coding		1..*	Coding	Code defined by a terminology system Fixed Value: (complex)
system		1..1	uri	Identity of the terminology system Fixed Value: http://terminology.hl7.org/CodeSystem/observation-category
code		1..1	code	Symbol in syntax defined by the system Fixed Value: exam
code	Σ	1..1	CodeableConcept	Type of observation (code / type) Binding: http://snomed.info/sct?fhir_vs (preferred): Visual Acuity Test
subject	Σ	1..1	Reference(Patient)	Who and/or what the observation is about
effective[x]	Σ	1..1	dateTime	Clinically relevant time/time-period for observation
Slices for value[x]	ΣC	0..1		Actual result Slice: Unordered, Closed by type:$this
valueRatio			Ratio
valueQuantity			Quantity
valueCodeableConcept			CodeableConcept
value[x]:valueRatio	ΣC	0..1	Ratio	Visual acuity expressed as a Snellen fraction inv-dh-va-01: Value shall include numerator value and denominator value
value[x]:valueQuantity	ΣC	0..1	Quantity	Visual acuity expressed as a simple quantity inv-dh-va-02: Value shall include value and unit
value[x]:valueCodeableConcept	ΣC	0..1	CodeableConcept	Visual acuity expressed as a code
method		0..1	CodeableConcept	Method used to measure visual acuity Binding: ObservationMethods (example): Methods for simple observations.
device		0..1	Reference(Device | DeviceMetric)	Type of chart used to measure visual acuity
Documentation for this format

Terminology Bindings

Path	Conformance	ValueSet / Code	URI
Observation.status	required	Fixed Value: final http://hl7.org/fhir/ValueSet/observation-status|4.0.1 from the FHIR Standard
Observation.category	preferred	ObservationCategoryCodes http://hl7.org/fhir/ValueSet/observation-category from the FHIR Standard
Observation.category:exam	preferred	Pattern: exam http://hl7.org/fhir/ValueSet/observation-category from the FHIR Standard
Observation.code	preferred	http://snomed.info/sct?fhir_vs http://snomed.info/sct?fhir_vs
Observation.method	example	ObservationMethods http://hl7.org/fhir/ValueSet/observation-methods from the FHIR Standard

Constraints

Id	Grade	Path(s)	Details	Requirements
inv-dh-va-01	error	Observation.value[x]:valueRatio	Value shall include numerator value and denominator value : numerator.value.exists() and denominator.value.exists()
inv-dh-va-02	error	Observation.value[x]:valueQuantity	Value shall include value and unit : value.exists() and unit.exists()

Name	Flags	Card.	Type	Description & Constraints
Observation	C	0..*	Observation	Sharpness or acuteness of vision 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
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	?!Σ	1..1	code	registered | preliminary | final | amended + Binding: ObservationStatus (required): Codes providing the status of an observation. Fixed Value: final
Slices for category		2..*	CodeableConcept	Classification of type of observation Slice: Unordered, Open by pattern:$this Binding: ObservationCategoryCodes (preferred): Codes for high level observation categories.
category:exam		1..1	CodeableConcept	Classification of type of observation Binding: ObservationCategoryCodes (preferred): Codes for high level observation categories. Required Pattern: At least the following
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
coding		1..*	Coding	Code defined by a terminology system Fixed Value: (complex)
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
system		1..1	uri	Identity of the terminology system Fixed Value: http://terminology.hl7.org/CodeSystem/observation-category
version		0..1	string	Version of the system - if relevant
code		1..1	code	Symbol in syntax defined by the system Fixed Value: exam
display		0..1	string	Representation defined by the system
userSelected		0..1	boolean	If this coding was chosen directly by the user
text		0..1	string	Plain text representation of the concept
code	Σ	1..1	CodeableConcept	Type of observation (code / type) Binding: http://snomed.info/sct?fhir_vs (preferred): Visual Acuity Test
subject	Σ	1..1	Reference(Patient)	Who and/or what the observation is about
focus	Σ	0..*	Reference(Resource)	What the observation is about, when it is not about the subject of record
encounter	Σ	0..1	Reference(Encounter)	Healthcare event during which this observation is made
effective[x]	Σ	1..1	dateTime	Clinically relevant time/time-period for observation
issued	Σ	0..1	instant	Date/Time this version was made available
performer	Σ	0..*	Reference(Practitioner | PractitionerRole | Organization | CareTeam | Patient | RelatedPerson)	Who is responsible for the observation
Slices for value[x]	ΣC	0..1		Actual result Slice: Unordered, Closed by type:$this
valueRatio			Ratio
valueQuantity			Quantity
valueCodeableConcept			CodeableConcept
value[x]:valueRatio	ΣC	0..1	Ratio	Visual acuity expressed as a Snellen fraction inv-dh-va-01: Value shall include numerator value and denominator value
value[x]:valueQuantity	ΣC	0..1	Quantity	Visual acuity expressed as a simple quantity inv-dh-va-02: Value shall include value and unit
value[x]:valueCodeableConcept	ΣC	0..1	CodeableConcept	Visual acuity expressed as a code
dataAbsentReason	C	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	Method used to measure visual acuity Binding: ObservationMethods (example): Methods for simple observations.
specimen		0..1	Reference(Specimen)	Specimen used for this observation
device		0..1	Reference(Device | DeviceMetric)	Type of chart used to measure visual acuity
referenceRange	C	0..*	BackboneElement	Provides guide for interpretation obs-3: Must have at least a low or a high or text
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored even if unrecognized
low	C	0..1	SimpleQuantity	Low Range, if relevant
high	C	0..1	SimpleQuantity	High Range, if relevant
type		0..1	CodeableConcept	Reference range qualifier Binding: ObservationReferenceRangeMeaningCodes (preferred): Code for the meaning of a reference range.
appliesTo		0..*	CodeableConcept	Reference range population Binding: ObservationReferenceRangeAppliesToCodes (example): Codes identifying the population the reference range applies to.
age		0..1	Range	Applicable age range, if relevant
text		0..1	string	Text based reference range in an observation
hasMember	Σ	0..*	Reference(Observation | QuestionnaireResponse | MolecularSequence)	Related resource that belongs to the Observation group
derivedFrom	Σ	0..*	Reference(DocumentReference | ImagingStudy | Media | QuestionnaireResponse | Observation | MolecularSequence)	Related measurements the observation is made from
component	Σ	0..*	BackboneElement	Component results
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored even if unrecognized
code	Σ	1..1	CodeableConcept	Type of component observation (code / type) Binding: LOINCCodes (example): Codes identifying names of simple observations.
value[x]	Σ	0..1		Actual component result
valueQuantity			Quantity
valueCodeableConcept			CodeableConcept
valueString			string
valueBoolean			boolean
valueInteger			integer
valueRange			Range
valueRatio			Ratio
valueSampledData			SampledData
valueTime			time
valueDateTime			dateTime
valuePeriod			Period
dataAbsentReason	C	0..1	CodeableConcept	Why the component result is missing Binding: DataAbsentReason (extensible): Codes specifying why the result (Observation.value[x]) is missing.
interpretation		0..*	CodeableConcept	High, low, normal, etc. Binding: ObservationInterpretationCodes (extensible): Codes identifying interpretations of observations.
referenceRange		0..*	See referenceRange (Observation)	Provides guide for interpretation of component result
Documentation for this format

Terminology Bindings

Path	Conformance	ValueSet / Code	URI
Observation.language	preferred	CommonLanguages Additional Bindings Purpose AllLanguages Max Binding http://hl7.org/fhir/ValueSet/languages from the FHIR Standard
Observation.status	required	Fixed Value: final http://hl7.org/fhir/ValueSet/observation-status|4.0.1 from the FHIR Standard
Observation.category	preferred	ObservationCategoryCodes http://hl7.org/fhir/ValueSet/observation-category from the FHIR Standard
Observation.category:exam	preferred	Pattern: exam http://hl7.org/fhir/ValueSet/observation-category from the FHIR Standard
Observation.code	preferred	http://snomed.info/sct?fhir_vs http://snomed.info/sct?fhir_vs
Observation.dataAbsentReason	extensible	DataAbsentReason http://hl7.org/fhir/ValueSet/data-absent-reason from the FHIR Standard
Observation.interpretation	extensible	ObservationInterpretationCodes http://hl7.org/fhir/ValueSet/observation-interpretation from the FHIR Standard
Observation.bodySite	example	SNOMEDCTBodyStructures http://hl7.org/fhir/ValueSet/body-site from the FHIR Standard
Observation.method	example	ObservationMethods http://hl7.org/fhir/ValueSet/observation-methods from the FHIR Standard
Observation.referenceRange.type	preferred	ObservationReferenceRangeMeaningCodes http://hl7.org/fhir/ValueSet/referencerange-meaning from the FHIR Standard
Observation.referenceRange.appliesTo	example	ObservationReferenceRangeAppliesToCodes http://hl7.org/fhir/ValueSet/referencerange-appliesto from the FHIR Standard
Observation.component.code	example	LOINCCodes (a valid code from LOINC) http://hl7.org/fhir/ValueSet/observation-codes from the FHIR Standard
Observation.component.dataAbsentReason	extensible	DataAbsentReason http://hl7.org/fhir/ValueSet/data-absent-reason from the FHIR Standard
Observation.component.interpretation	extensible	ObservationInterpretationCodes http://hl7.org/fhir/ValueSet/observation-interpretation from the FHIR Standard

Constraints

Id	Grade	Path(s)	Details	Requirements
inv-dh-va-01	error	Observation.value[x]:valueRatio	Value shall include numerator value and denominator value : numerator.value.exists() and denominator.value.exists()
inv-dh-va-02	error	Observation.value[x]:valueQuantity	Value shall include value and unit : value.exists() and unit.exists()

Differential View

This structure is derived from Observation

Name	Flags	Card.	Type	Description & Constraints
Observation		0..*	Observation	Sharpness or acuteness of vision
status		1..1	code	registered | preliminary | final | amended + Fixed Value: final
Slices for category		2..*	CodeableConcept	Classification of type of observation Slice: Unordered, Open by pattern:$this
category:exam		1..1	CodeableConcept	Classification of type of observation Required Pattern: At least the following
coding		1..*	Coding	Code defined by a terminology system Fixed Value: (complex)
system		1..1	uri	Identity of the terminology system Fixed Value: http://terminology.hl7.org/CodeSystem/observation-category
code		1..1	code	Symbol in syntax defined by the system Fixed Value: exam
code		1..1	CodeableConcept	Type of observation (code / type) Binding: http://snomed.info/sct?fhir_vs (preferred): Visual Acuity Test
subject		1..1	Reference(Patient)	Who and/or what the observation is about
effective[x]		1..1	dateTime	Clinically relevant time/time-period for observation
value[x]		0..1		Actual result
valueRatio			Ratio
valueQuantity			Quantity
valueCodeableConcept			CodeableConcept
Slices for value[x]				Content/Rules for all slices
value[x]:valueRatio	C	0..1	Ratio	Visual acuity expressed as a Snellen fraction inv-dh-va-01: Value shall include numerator value and denominator value
value[x]:valueQuantity	C	0..1	Quantity	Visual acuity expressed as a simple quantity inv-dh-va-02: Value shall include value and unit
value[x]:valueCodeableConcept		0..1	CodeableConcept	Visual acuity expressed as a code
method		0..1	CodeableConcept	Method used to measure visual acuity
device		0..1	Reference(Device | DeviceMetric)	Type of chart used to measure visual acuity
Documentation for this format

Terminology Bindings (Differential)

Path	Conformance	ValueSet	URI
Observation.code	preferred	http://snomed.info/sct?fhir_vs http://snomed.info/sct?fhir_vs

Constraints

Id	Grade	Path(s)	Details	Requirements
inv-dh-va-01	error	Observation.value[x]:valueRatio	Value shall include numerator value and denominator value : numerator.value.exists() and denominator.value.exists()
inv-dh-va-02	error	Observation.value[x]:valueQuantity	Value shall include value and unit : value.exists() and unit.exists()

Key Elements View

Name	Flags	Card.	Type	Description & Constraints
Observation	C	0..*	Observation	Sharpness or acuteness of vision 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
implicitRules	?!Σ	0..1	uri	A set of rules under which this content was created
modifierExtension	?!	0..*	Extension	Extensions that cannot be ignored
status	?!Σ	1..1	code	registered | preliminary | final | amended + Binding: ObservationStatus (required): Codes providing the status of an observation. Fixed Value: final
Slices for category		2..*	CodeableConcept	Classification of type of observation Slice: Unordered, Open by pattern:$this Binding: ObservationCategoryCodes (preferred): Codes for high level observation categories.
category:exam		1..1	CodeableConcept	Classification of type of observation Binding: ObservationCategoryCodes (preferred): Codes for high level observation categories. Required Pattern: At least the following
coding		1..*	Coding	Code defined by a terminology system Fixed Value: (complex)
system		1..1	uri	Identity of the terminology system Fixed Value: http://terminology.hl7.org/CodeSystem/observation-category
code		1..1	code	Symbol in syntax defined by the system Fixed Value: exam
code	Σ	1..1	CodeableConcept	Type of observation (code / type) Binding: http://snomed.info/sct?fhir_vs (preferred): Visual Acuity Test
subject	Σ	1..1	Reference(Patient)	Who and/or what the observation is about
effective[x]	Σ	1..1	dateTime	Clinically relevant time/time-period for observation
Slices for value[x]	ΣC	0..1		Actual result Slice: Unordered, Closed by type:$this
valueRatio			Ratio
valueQuantity			Quantity
valueCodeableConcept			CodeableConcept
value[x]:valueRatio	ΣC	0..1	Ratio	Visual acuity expressed as a Snellen fraction inv-dh-va-01: Value shall include numerator value and denominator value
value[x]:valueQuantity	ΣC	0..1	Quantity	Visual acuity expressed as a simple quantity inv-dh-va-02: Value shall include value and unit
value[x]:valueCodeableConcept	ΣC	0..1	CodeableConcept	Visual acuity expressed as a code
method		0..1	CodeableConcept	Method used to measure visual acuity Binding: ObservationMethods (example): Methods for simple observations.
device		0..1	Reference(Device | DeviceMetric)	Type of chart used to measure visual acuity
Documentation for this format

Terminology Bindings

Path	Conformance	ValueSet / Code	URI
Observation.status	required	Fixed Value: final http://hl7.org/fhir/ValueSet/observation-status|4.0.1 from the FHIR Standard
Observation.category	preferred	ObservationCategoryCodes http://hl7.org/fhir/ValueSet/observation-category from the FHIR Standard
Observation.category:exam	preferred	Pattern: exam http://hl7.org/fhir/ValueSet/observation-category from the FHIR Standard
Observation.code	preferred	http://snomed.info/sct?fhir_vs http://snomed.info/sct?fhir_vs
Observation.method	example	ObservationMethods http://hl7.org/fhir/ValueSet/observation-methods from the FHIR Standard

Constraints

Id	Grade	Path(s)	Details	Requirements
inv-dh-va-01	error	Observation.value[x]:valueRatio	Value shall include numerator value and denominator value : numerator.value.exists() and denominator.value.exists()
inv-dh-va-02	error	Observation.value[x]:valueQuantity	Value shall include value and unit : value.exists() and unit.exists()

Snapshot View

Name	Flags	Card.	Type	Description & Constraints
Observation	C	0..*	Observation	Sharpness or acuteness of vision 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
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	?!Σ	1..1	code	registered | preliminary | final | amended + Binding: ObservationStatus (required): Codes providing the status of an observation. Fixed Value: final
Slices for category		2..*	CodeableConcept	Classification of type of observation Slice: Unordered, Open by pattern:$this Binding: ObservationCategoryCodes (preferred): Codes for high level observation categories.
category:exam		1..1	CodeableConcept	Classification of type of observation Binding: ObservationCategoryCodes (preferred): Codes for high level observation categories. Required Pattern: At least the following
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
coding		1..*	Coding	Code defined by a terminology system Fixed Value: (complex)
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
system		1..1	uri	Identity of the terminology system Fixed Value: http://terminology.hl7.org/CodeSystem/observation-category
version		0..1	string	Version of the system - if relevant
code		1..1	code	Symbol in syntax defined by the system Fixed Value: exam
display		0..1	string	Representation defined by the system
userSelected		0..1	boolean	If this coding was chosen directly by the user
text		0..1	string	Plain text representation of the concept
code	Σ	1..1	CodeableConcept	Type of observation (code / type) Binding: http://snomed.info/sct?fhir_vs (preferred): Visual Acuity Test
subject	Σ	1..1	Reference(Patient)	Who and/or what the observation is about
focus	Σ	0..*	Reference(Resource)	What the observation is about, when it is not about the subject of record
encounter	Σ	0..1	Reference(Encounter)	Healthcare event during which this observation is made
effective[x]	Σ	1..1	dateTime	Clinically relevant time/time-period for observation
issued	Σ	0..1	instant	Date/Time this version was made available
performer	Σ	0..*	Reference(Practitioner | PractitionerRole | Organization | CareTeam | Patient | RelatedPerson)	Who is responsible for the observation
Slices for value[x]	ΣC	0..1		Actual result Slice: Unordered, Closed by type:$this
valueRatio			Ratio
valueQuantity			Quantity
valueCodeableConcept			CodeableConcept
value[x]:valueRatio	ΣC	0..1	Ratio	Visual acuity expressed as a Snellen fraction inv-dh-va-01: Value shall include numerator value and denominator value
value[x]:valueQuantity	ΣC	0..1	Quantity	Visual acuity expressed as a simple quantity inv-dh-va-02: Value shall include value and unit
value[x]:valueCodeableConcept	ΣC	0..1	CodeableConcept	Visual acuity expressed as a code
dataAbsentReason	C	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	Method used to measure visual acuity Binding: ObservationMethods (example): Methods for simple observations.
specimen		0..1	Reference(Specimen)	Specimen used for this observation
device		0..1	Reference(Device | DeviceMetric)	Type of chart used to measure visual acuity
referenceRange	C	0..*	BackboneElement	Provides guide for interpretation obs-3: Must have at least a low or a high or text
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored even if unrecognized
low	C	0..1	SimpleQuantity	Low Range, if relevant
high	C	0..1	SimpleQuantity	High Range, if relevant
type		0..1	CodeableConcept	Reference range qualifier Binding: ObservationReferenceRangeMeaningCodes (preferred): Code for the meaning of a reference range.
appliesTo		0..*	CodeableConcept	Reference range population Binding: ObservationReferenceRangeAppliesToCodes (example): Codes identifying the population the reference range applies to.
age		0..1	Range	Applicable age range, if relevant
text		0..1	string	Text based reference range in an observation
hasMember	Σ	0..*	Reference(Observation | QuestionnaireResponse | MolecularSequence)	Related resource that belongs to the Observation group
derivedFrom	Σ	0..*	Reference(DocumentReference | ImagingStudy | Media | QuestionnaireResponse | Observation | MolecularSequence)	Related measurements the observation is made from
component	Σ	0..*	BackboneElement	Component results
id		0..1	string	Unique id for inter-element referencing
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!Σ	0..*	Extension	Extensions that cannot be ignored even if unrecognized
code	Σ	1..1	CodeableConcept	Type of component observation (code / type) Binding: LOINCCodes (example): Codes identifying names of simple observations.
value[x]	Σ	0..1		Actual component result
valueQuantity			Quantity
valueCodeableConcept			CodeableConcept
valueString			string
valueBoolean			boolean
valueInteger			integer
valueRange			Range
valueRatio			Ratio
valueSampledData			SampledData
valueTime			time
valueDateTime			dateTime
valuePeriod			Period
dataAbsentReason	C	0..1	CodeableConcept	Why the component result is missing Binding: DataAbsentReason (extensible): Codes specifying why the result (Observation.value[x]) is missing.
interpretation		0..*	CodeableConcept	High, low, normal, etc. Binding: ObservationInterpretationCodes (extensible): Codes identifying interpretations of observations.
referenceRange		0..*	See referenceRange (Observation)	Provides guide for interpretation of component result
Documentation for this format

Terminology Bindings

Path	Conformance	ValueSet / Code	URI
Observation.language	preferred	CommonLanguages Additional Bindings Purpose AllLanguages Max Binding http://hl7.org/fhir/ValueSet/languages from the FHIR Standard
Observation.status	required	Fixed Value: final http://hl7.org/fhir/ValueSet/observation-status|4.0.1 from the FHIR Standard
Observation.category	preferred	ObservationCategoryCodes http://hl7.org/fhir/ValueSet/observation-category from the FHIR Standard
Observation.category:exam	preferred	Pattern: exam http://hl7.org/fhir/ValueSet/observation-category from the FHIR Standard
Observation.code	preferred	http://snomed.info/sct?fhir_vs http://snomed.info/sct?fhir_vs
Observation.dataAbsentReason	extensible	DataAbsentReason http://hl7.org/fhir/ValueSet/data-absent-reason from the FHIR Standard
Observation.interpretation	extensible	ObservationInterpretationCodes http://hl7.org/fhir/ValueSet/observation-interpretation from the FHIR Standard
Observation.bodySite	example	SNOMEDCTBodyStructures http://hl7.org/fhir/ValueSet/body-site from the FHIR Standard
Observation.method	example	ObservationMethods http://hl7.org/fhir/ValueSet/observation-methods from the FHIR Standard
Observation.referenceRange.type	preferred	ObservationReferenceRangeMeaningCodes http://hl7.org/fhir/ValueSet/referencerange-meaning from the FHIR Standard
Observation.referenceRange.appliesTo	example	ObservationReferenceRangeAppliesToCodes http://hl7.org/fhir/ValueSet/referencerange-appliesto from the FHIR Standard
Observation.component.code	example	LOINCCodes (a valid code from LOINC) http://hl7.org/fhir/ValueSet/observation-codes from the FHIR Standard
Observation.component.dataAbsentReason	extensible	DataAbsentReason http://hl7.org/fhir/ValueSet/data-absent-reason from the FHIR Standard
Observation.component.interpretation	extensible	ObservationInterpretationCodes http://hl7.org/fhir/ValueSet/observation-interpretation from the FHIR Standard

Constraints

Id	Grade	Path(s)	Details	Requirements
inv-dh-va-01	error	Observation.value[x]:valueRatio	Value shall include numerator value and denominator value : numerator.value.exists() and denominator.value.exists()
inv-dh-va-02	error	Observation.value[x]:valueQuantity	Value shall include value and unit : value.exists() and unit.exists()

This structure is derived from Observation

Summary

Mandatory: 3 elements
Fixed: 1 element

Slices

This structure defines the following Slices:

• The element 1 is sliced based on the value of Observation.category

No mandatory or optional search parameters for ADHA Visual Acuityprofile.