MyHealth@EU Core
1.0.0 - trial-use 150

MyHealth@EU Core - Local Development build (v1.0.0) built by the FHIR (HL7® FHIR® Standard) Build Tools. See the Directory of published versions

## Data Type Profile: Ratio (MyHealth@EU)

Official URL: http://fhir.ehdsi.eu/core/StructureDefinition/Ratio-myhealth | Version: 1.0.0
Active as of 2026-05-05 | Computable Name: RatioMyHealth

This profile of the Ratio data type constraints the Ratio (MyHealth@EU) profile defining a core value set for UCUM. The Ratio (MyHealth@EU) imposes the usage of the UCUM as the code system for units and allows expressing uncertainty of measurement.

This profile of the Ratio data type imposes the usage of the UCUM as the code system for units and allows expressing uncertainty of measurement

Usages:

- Use this DataType Profile: Observation: Medical Test Result (Core), Medication (Core), MedicationRequest (Core) and MedicationStatement (Core)

You can also check for usages in the FHIR IG Statistics

### Formal Views of Profile Content

Description of Profiles, Differentials, Snapshots and how the different presentations work.

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

Name | Flags | Card. | Type | Description & Constraints Filter: Bindings Constraints Obligations
--- | --- | --- | --- | ---
Ratio | C | 0..* | Ratio | A measured ratio using UCUM Constraints: rat-1
Slices for extension |  |  |  | Content/Rules for all slices
extension:uncertainty |  | 0..1 | decimal | Standard Deviation (same units as the quantity) URL: http://hl7.org/fhir/StructureDefinition/iso21090-uncertainty
extension:uncertaintyType |  | 0..1 | code | Probability Distribution Type for uncertainty URL: http://hl7.org/fhir/StructureDefinition/iso21090-uncertaintyType Binding: ProbabilityDistributionType (required)
numerator | S Σ | 0..1 | QuantityMyHealth | A measured amount using UCUM
denominator | S Σ | 0..1 | QuantityMyHealth | A measured amount using UCUM
Documentation for this format

#### Constraints

Id | Grade | Path(s) | Description | Expression
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()`
rat-1 | error | Ratio | Numerator and denominator SHALL both be present, or both are absent. If both are absent, there SHALL be some extension present | `(numerator.empty() xor denominator.exists()) and (numerator.exists() or extension.exists())`

This structure is derived from Ratio

Name | Flags | Card. | Type | Description & Constraints Filter: Bindings Constraints Obligations
--- | --- | --- | --- | ---
Ratio |  | 0..* | Ratio | A measured ratio using UCUM
Slices for extension |  |  |  | Content/Rules for all slices
extension:uncertainty |  | 0..1 | decimal | Standard Deviation (same units as the quantity) URL: http://hl7.org/fhir/StructureDefinition/iso21090-uncertainty
extension:uncertaintyType |  | 0..1 | code | Probability Distribution Type for uncertainty URL: http://hl7.org/fhir/StructureDefinition/iso21090-uncertaintyType Binding: ProbabilityDistributionType (required)
numerator | S | 0..1 | QuantityMyHealth | A measured amount using UCUM
denominator | S | 0..1 | QuantityMyHealth | A measured amount using UCUM
Documentation for this format

Name | Flags | Card. | Type | Description & Constraints Filter: Bindings Constraints Obligations
--- | --- | --- | --- | ---
Ratio | C | 0..* | Ratio | A measured ratio using UCUM Constraints: rat-1
id |  | 0..1 | string | Unique id for inter-element referencing
Slices for extension |  | 0..* | Extension | Additional content defined by implementations Slice: Unordered, Open by value:url
extension:uncertainty |  | 0..1 | decimal | Standard Deviation (same units as the quantity) URL: http://hl7.org/fhir/StructureDefinition/iso21090-uncertainty
extension:uncertaintyType |  | 0..1 | code | Probability Distribution Type for uncertainty URL: http://hl7.org/fhir/StructureDefinition/iso21090-uncertaintyType Binding: ProbabilityDistributionType (required)
numerator | S Σ | 0..1 | QuantityMyHealth | A measured amount using UCUM
denominator | S Σ | 0..1 | QuantityMyHealth | A measured amount using UCUM
Documentation for this format

#### Constraints

Id | Grade | Path(s) | Description | Expression
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()`
rat-1 | error | Ratio | Numerator and denominator SHALL both be present, or both are absent. If both are absent, there SHALL be some extension present | `(numerator.empty() xor denominator.exists()) and (numerator.exists() or extension.exists())`

This structure is derived from Ratio

Summary

Must-Support: 2 elements

Structures

This structure refers to these other structures:

- Quantity (MyHealth@EU) (http://fhir.ehdsi.eu/core/StructureDefinition/Quantity-myhealth)

Extensions

This structure refers to these extensions:

- http://hl7.org/fhir/StructureDefinition/iso21090-uncertainty|5.2.0
- http://hl7.org/fhir/StructureDefinition/iso21090-uncertaintyType|5.2.0

Key Elements View

Name | Flags | Card. | Type | Description & Constraints Filter: Bindings Constraints Obligations
--- | --- | --- | --- | ---
Ratio | C | 0..* | Ratio | A measured ratio using UCUM Constraints: rat-1
Slices for extension |  |  |  | Content/Rules for all slices
extension:uncertainty |  | 0..1 | decimal | Standard Deviation (same units as the quantity) URL: http://hl7.org/fhir/StructureDefinition/iso21090-uncertainty
extension:uncertaintyType |  | 0..1 | code | Probability Distribution Type for uncertainty URL: http://hl7.org/fhir/StructureDefinition/iso21090-uncertaintyType Binding: ProbabilityDistributionType (required)
numerator | S Σ | 0..1 | QuantityMyHealth | A measured amount using UCUM
denominator | S Σ | 0..1 | QuantityMyHealth | A measured amount using UCUM
Documentation for this format

#### Constraints

Id | Grade | Path(s) | Description | Expression
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()`
rat-1 | error | Ratio | Numerator and denominator SHALL both be present, or both are absent. If both are absent, there SHALL be some extension present | `(numerator.empty() xor denominator.exists()) and (numerator.exists() or extension.exists())`

Differential View

This structure is derived from Ratio

Name | Flags | Card. | Type | Description & Constraints Filter: Bindings Constraints Obligations
--- | --- | --- | --- | ---
Ratio |  | 0..* | Ratio | A measured ratio using UCUM
Slices for extension |  |  |  | Content/Rules for all slices
extension:uncertainty |  | 0..1 | decimal | Standard Deviation (same units as the quantity) URL: http://hl7.org/fhir/StructureDefinition/iso21090-uncertainty
extension:uncertaintyType |  | 0..1 | code | Probability Distribution Type for uncertainty URL: http://hl7.org/fhir/StructureDefinition/iso21090-uncertaintyType Binding: ProbabilityDistributionType (required)
numerator | S | 0..1 | QuantityMyHealth | A measured amount using UCUM
denominator | S | 0..1 | QuantityMyHealth | A measured amount using UCUM
Documentation for this format

Snapshot View

Name | Flags | Card. | Type | Description & Constraints Filter: Bindings Constraints Obligations
--- | --- | --- | --- | ---
Ratio | C | 0..* | Ratio | A measured ratio using UCUM Constraints: rat-1
id |  | 0..1 | string | Unique id for inter-element referencing
Slices for extension |  | 0..* | Extension | Additional content defined by implementations Slice: Unordered, Open by value:url
extension:uncertainty |  | 0..1 | decimal | Standard Deviation (same units as the quantity) URL: http://hl7.org/fhir/StructureDefinition/iso21090-uncertainty
extension:uncertaintyType |  | 0..1 | code | Probability Distribution Type for uncertainty URL: http://hl7.org/fhir/StructureDefinition/iso21090-uncertaintyType Binding: ProbabilityDistributionType (required)
numerator | S Σ | 0..1 | QuantityMyHealth | A measured amount using UCUM
denominator | S Σ | 0..1 | QuantityMyHealth | A measured amount using UCUM
Documentation for this format

#### Constraints

Id | Grade | Path(s) | Description | Expression
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()`
rat-1 | error | Ratio | Numerator and denominator SHALL both be present, or both are absent. If both are absent, there SHALL be some extension present | `(numerator.empty() xor denominator.exists()) and (numerator.exists() or extension.exists())`

This structure is derived from Ratio

Summary

Must-Support: 2 elements

Structures

This structure refers to these other structures:

- Quantity (MyHealth@EU) (http://fhir.ehdsi.eu/core/StructureDefinition/Quantity-myhealth)

Extensions

This structure refers to these extensions:

- http://hl7.org/fhir/StructureDefinition/iso21090-uncertainty|5.2.0
- http://hl7.org/fhir/StructureDefinition/iso21090-uncertaintyType|5.2.0

Other representations of profile: CSV, Excel, Schematron