HL7 FHIR Implementation Guide Laboratory Report
0.2.0 - trial-use

HL7 FHIR Implementation Guide Laboratory Report, published by HL7 Italia. This guide is not an authorized publication; it is the continuous build for version 0.2.0 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/hl7-it/lab-report/ and changes regularly. See the Directory of published versions

## Data Type Profile: QuantityLab - Detailed Descriptions

Page standards status: Trial-use | Maturity Level: 1

Definitions for the quantity-it-lab data type profile.

- Key Elements Table
- Differential Elements Table
- Snapshot Elements Table

Guidance on how to interpret the contents of this table can be foundhere

0. Quantity
Definition | A measured amount (or an amount that can potentially be measured) and uncertainty of the measurement. Note that measured amounts include amounts that are not precisely quantified, including amounts involving arbitrary units and floating currencies. This profile imposes that the code system for units be UCUM. A measured amount (or an amount that can potentially be measured). Note that measured amounts include amounts that are not precisely quantified, including amounts involving arbitrary units and floating currencies.
Short | A measured amount using UCUMA measured or measurable amount
Comments | The context of use may frequently define what kind of quantity this is and therefore what kind of units can be used. The context of use may also restrict the values for the comparator.
Control | 0..* This element is affected by the following invariants: ele-1
Is Modifier | false
Invariants | ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count())) qty-3: If a code for the unit is present, the system SHALL also be present (`code.empty() or system.exists()`) qty-3: If a code for the unit is present, the system SHALL also be present (code.empty() or system.exists())
2. Quantity.extension:uncertainty
Slice Name | uncertainty
Definition | The primary measure of variance/uncertainty of the value (the square root of the sum of the squares of the differences between all data points and the mean).
Short | Standard Deviation (same units as the quantity)
Comments | standardDeviation has the same units as the quantity. It is used to normalize the data for computing the distribution function. Applications that cannot deal with probability distributions can still get an idea about the confidence level by looking at standardDeviation.
Control | 0..1
Type | Extension(Uncertainty) (Extension Type: decimal)
Is Modifier | false
Summary | false
Invariants | ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count())) ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
4. Quantity.extension:uncertaintyType
Slice Name | uncertaintyType
Definition | A code specifying the type of probability distribution for the uncertainty.
Short | Probability Distribution Type for uncertainty
Comments | This is only meaningful if there is also an uncertainty extension. If there is an uncertainty extension with no type, this means that the probability distribution type is unknown. In that case, the uncertainty has the meaning of an informal guess.
Control | 0..1
Type | Extension(Uncertainty type) (Extension Type: code)
Is Modifier | false
Summary | false
Invariants | ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count())) ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
6. Quantity.value
Definition | The value of the measured amount. The value includes an implicit precision in the presentation of the value.
Short | Valore della misurazione.Numerical value (with implicit precision)
Comments | The implicit precision in the value should always be honored. Monetary values have their own rules for handling precision (refer to standard accounting text books).
Control | 0..1
Type | decimal
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | true
Requirements | Precision is handled implicitly in almost all cases of measurement.
Invariants | ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
8. Quantity.comparator
Definition | How the value should be understood and represented - whether the actual value is greater or less than the stated value due to measurement issues; e.g. if the comparator is "<" , then the real value is < stated value.
Short | < | <= | >= | > - how to understand the value
Control | 0..1
Binding | The codes SHALL be taken from QuantityComparator http://hl7.org/fhir/ValueSet/quantity-comparator|4.0.1 (required to `http://hl7.org/fhir/ValueSet/quantity-comparator|4.0.1` ) How the Quantity should be understood and represented.
Type | code
Is Modifier | true because This is labeled as "Is Modifier" because the comparator modifies the interpretation of the value significantly. If there is no comparator, then there is no modification of the value
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | true
Requirements | Need a framework for handling measures where the value is <5ug/L or >400mg/L due to the limitations of measuring methodology.
Meaning if Missing | If there is no comparator, then there is no modification of the value
Invariants | ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
10. Quantity.unit
Definition | A human-readable form of the unit.
Short | Descrizione testuale dell'unità di misura.Unit representation
Control | 0..1
Type | string
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | true
Requirements | There are many representations for units of measure and in many contexts, particular representations are fixed and required. I.e. mcg for micrograms.
Invariants | ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
12. Quantity.system
Definition | The identification of the system that provides the coded form of the unit.
Short | UCUM system for unitsSystem that defines coded unit form
Control | 10..1 This element is affected by the following invariants: qty-3
Type | uri
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Must Support | true
Summary | true
Requirements | Need to know the system that defines the coded form of the unit.
Fixed Value | `http://unitsofmeasure.org`
Invariants | ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
14. Quantity.code
Definition | A computer processable form of the unit in some unit representation system.
Short | Descrizione codificata dell'unità di misura secondo UCUM.Coded form of the unit
Comments | The preferred system is UCUM, but SNOMED CT can also be used (for customary units) or ISO 4217 for currency. The context of use may additionally require a code from a particular system.
Control | 10..1
Binding | The codes SHALL be taken from For codes, see UCUMCodes (required to `http://hl7.org/fhir/ValueSet/ucum-units` )
Type | code
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Must Support | true
Summary | true
Requirements | Need a computable form of the unit that is fixed across all forms. UCUM provides this for quantities, but SNOMED CT provides many units of interest.
Invariants | ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))

Guidance on how to interpret the contents of this table can be foundhere

0. Quantity
2. Quantity.value
Short | Valore della misurazione.
4. Quantity.unit
Short | Descrizione testuale dell'unità di misura.
6. Quantity.code
Short | Descrizione codificata dell'unità di misura secondo UCUM.
Binding | The codes SHALL be taken from UCUMCodes (required to `http://hl7.org/fhir/ValueSet/ucum-units` )

Guidance on how to interpret the contents of this table can be foundhere

0. Quantity
Definition | A measured amount (or an amount that can potentially be measured) and uncertainty of the measurement. Note that measured amounts include amounts that are not precisely quantified, including amounts involving arbitrary units and floating currencies. This profile imposes that the code system for units be UCUM.
Short | A measured amount using UCUM
Comments | The context of use may frequently define what kind of quantity this is and therefore what kind of units can be used. The context of use may also restrict the values for the comparator.
Control | 0..* This element is affected by the following invariants: ele-1
Is Modifier | false
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`) qty-3: If a code for the unit is present, the system SHALL also be present (`code.empty() or system.exists()`)
2. Quantity.id
Definition | Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
Short | Unique id for inter-element referencing
Control | 0..1
Type | string
Is Modifier | false
XML Format | In the XML format, this property is represented as an attribute.
Summary | false
4. Quantity.extension
Definition | May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.
Short | Additional content defined by implementations
Comments | There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.
Control | 0..*
Type | Extension
Is Modifier | false
Summary | false
Alternate Names | extensions, user content
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`) ext-1: Must have either extensions or value[x], not both (`extension.exists() != value.exists()`)
Slicing | This element introduces a set of slices on `Quantity.extension`. The slices areUnordered and Open, and can be differentiated using the following discriminators: value @ url
6. Quantity.extension:uncertainty
Slice Name | uncertainty
Definition | The primary measure of variance/uncertainty of the value (the square root of the sum of the squares of the differences between all data points and the mean).
Short | Standard Deviation (same units as the quantity)
Comments | standardDeviation has the same units as the quantity. It is used to normalize the data for computing the distribution function. Applications that cannot deal with probability distributions can still get an idea about the confidence level by looking at standardDeviation.
Control | 0..1
Type | Extension(Uncertainty) (Extension Type: decimal)
Is Modifier | false
Summary | false
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`) ext-1: Must have either extensions or value[x], not both (`extension.exists() != value.exists()`)
8. Quantity.extension:uncertaintyType
Slice Name | uncertaintyType
Definition | A code specifying the type of probability distribution for the uncertainty.
Short | Probability Distribution Type for uncertainty
Comments | This is only meaningful if there is also an uncertainty extension. If there is an uncertainty extension with no type, this means that the probability distribution type is unknown. In that case, the uncertainty has the meaning of an informal guess.
Control | 0..1
Type | Extension(Uncertainty type) (Extension Type: code)
Is Modifier | false
Summary | false
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`) ext-1: Must have either extensions or value[x], not both (`extension.exists() != value.exists()`)
10. Quantity.value
Definition | The value of the measured amount. The value includes an implicit precision in the presentation of the value.
Short | Valore della misurazione.
Comments | The implicit precision in the value should always be honored. Monetary values have their own rules for handling precision (refer to standard accounting text books).
Control | 0..1
Type | decimal
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | true
Requirements | Precision is handled implicitly in almost all cases of measurement.
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
12. Quantity.comparator
Definition | How the value should be understood and represented - whether the actual value is greater or less than the stated value due to measurement issues; e.g. if the comparator is "<" , then the real value is < stated value.
Short | < | <= | >= | > - how to understand the value
Control | 0..1
Binding | The codes SHALL be taken from QuantityComparator (required to `http://hl7.org/fhir/ValueSet/quantity-comparator|4.0.1` ) How the Quantity should be understood and represented.
Type | code
Is Modifier | true because This is labeled as "Is Modifier" because the comparator modifies the interpretation of the value significantly. If there is no comparator, then there is no modification of the value
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | true
Requirements | Need a framework for handling measures where the value is <5ug/L or >400mg/L due to the limitations of measuring methodology.
Meaning if Missing | If there is no comparator, then there is no modification of the value
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
14. Quantity.unit
Definition | A human-readable form of the unit.
Short | Descrizione testuale dell'unità di misura.
Control | 0..1
Type | string
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | true
Requirements | There are many representations for units of measure and in many contexts, particular representations are fixed and required. I.e. mcg for micrograms.
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
16. Quantity.system
Definition | The identification of the system that provides the coded form of the unit.
Short | UCUM system for units
Control | 1..1 This element is affected by the following invariants: qty-3
Type | uri
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Must Support | true
Summary | true
Requirements | Need to know the system that defines the coded form of the unit.
Fixed Value | `http://unitsofmeasure.org`
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
18. Quantity.code
Definition | A computer processable form of the unit in some unit representation system.
Short | Descrizione codificata dell'unità di misura secondo UCUM.
Comments | The preferred system is UCUM, but SNOMED CT can also be used (for customary units) or ISO 4217 for currency. The context of use may additionally require a code from a particular system.
Control | 1..1
Binding | The codes SHALL be taken from UCUMCodes (required to `http://hl7.org/fhir/ValueSet/ucum-units` )
Type | code
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Must Support | true
Summary | true
Requirements | Need a computable form of the unit that is fixed across all forms. UCUM provides this for quantities, but SNOMED CT provides many units of interest.
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)