FHIR Extensions Pack
5.4.0 - May 2026 International flag

FHIR Extensions Pack, published by HL7 International / FHIR Infrastructure. This guide is not an authorized publication; it is the continuous build for version 5.4.0 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/HL7/fhir-extensions/ and changes regularly. See the Directory of published versions

Extension: Quantity Accuracy

Official URL: http://hl7.org/fhir/StructureDefinition/quantity-accuracy Version: 5.4.0
Standards status: Draft Maturity Level: 0 Responsible: HL7 International / Orders and Observations Computable Name: QuantityAccuracy
Other Identifiers: OID:2.16.840.1.113883.4.642.40.97.42.132

The absolute of the maximum deviation of the actual value from the reported value.

Accuracy is particularly applicable to measured or observed values. The reported observed value should be precise enough to reflect this accuracy, for example an observed value of 3.2 kg with an accuracy of 0.04 kg would be nonsensical. On the other hand, an observed value of 3.02 kg with an accuracy of 0.04 kg would indicate that the actual value is in the range of 3.02±0.04 kg or [2.98, 3.06] kg.

When applied to a DeviceMetric, it expresses the maximum deviation of values reported by the metric over the entire range of measurement.

Accuracy is usually in the same units as the reported value. Accuracy valueQuantity units SHOULD be provided for clarity; if omitted, they are implied to be the same as the reported value's units (or the DeviceMetric units).

This is an draft extension definition; the committee is seeking implementation feedback, and the definition or contents of the extension may change in future versions

Context of Use

This extension may be used on the following element(s)

Usage info

Usages:

  • This Extension is not used by any profiles in this Specification

You can also check for usages in the FHIR IG Statistics

Changes since version 5.3.0:

  • No changes

    • Formal Views of Extension Content

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

    This structure is derived from Extension

    Summary

    Simple Extension with the type Quantity: The absolute of the maximum deviation of the actual value from the reported value.

    Accuracy is particularly applicable to measured or observed values. The reported observed value should be precise enough to reflect this accuracy, for example an observed value of 3.2 kg with an accuracy of 0.04 kg would be nonsensical. On the other hand, an observed value of 3.02 kg with an accuracy of 0.04 kg would indicate that the actual value is in the range of 3.02±0.04 kg or [2.98, 3.06] kg.

    When applied to a DeviceMetric, it expresses the maximum deviation of values reported by the metric over the entire range of measurement.

    Accuracy is usually in the same units as the reported value. Accuracy valueQuantity units SHOULD be provided for clarity; if omitted, they are implied to be the same as the reported value's units (or the DeviceMetric units).

    Maturity: 0

    This structure is derived from Extension

    NameFlagsCard.TypeDescription & Constraints    Filter: doco
    Extension 0..1 Extension Absolute maximum deviation from actual value
    Extension.extension 0..0 Extension
    Extension.url 1..1 uri "http://hl7.org/fhir/StructureDefinition/quantity-accuracy"
    Extension.value[x] 0..1 Quantity Absolute maximum deviation of the reported value from the actual value
    Extension.valueQuantity.value 1..1 decimal Numerical value (with implicit precision)

    doco Documentation for this format
    NameFlagsCard.TypeDescription & Constraints    Filter: doco
    Extension 0..1 Extension Absolute maximum deviation from actual value
    Extension.id 0..1 id Unique id for inter-element referencing
    Extension.extension 0..0 Extension
    Slice: Unordered, Open by value:url

    Slicing Note: The rules on this element (including its children) apply to all the slices, but are not repeated in them
    Extension.url 1..1 uri "http://hl7.org/fhir/StructureDefinition/quantity-accuracy"
    Extension.value[x] 0..1 Quantity Absolute maximum deviation of the reported value from the actual value
    Extension.value[x].id 0..1 id Unique id for inter-element referencing
    Extension.value[x].extension 0..* Extension Additional content defined by implementations
    Slice: Unordered, Open by value:url
    Extension.value[x].value This element is included in summaries. 1..1 decimal Numerical value (with implicit precision)
    Extension.value[x].comparator This element is a modifier element. This element is included in summaries. 0..1 code < | <= | >= | > | ad - how to understand the value
    Binding: QuantityComparator (required): How the Quantity should be understood and represented.
    Extension.value[x].unit This element is included in summaries. 0..1 string Unit representation
    Extension.value[x].system This element is included in summaries. C 0..1 uri System that defines coded unit form
    Extension.value[x].code This element is included in summaries. C 0..1 code Coded form of the unit

    doco Documentation for this format

    This structure is derived from Extension

    Summary

    Simple Extension with the type Quantity: The absolute of the maximum deviation of the actual value from the reported value.

    Accuracy is particularly applicable to measured or observed values. The reported observed value should be precise enough to reflect this accuracy, for example an observed value of 3.2 kg with an accuracy of 0.04 kg would be nonsensical. On the other hand, an observed value of 3.02 kg with an accuracy of 0.04 kg would indicate that the actual value is in the range of 3.02±0.04 kg or [2.98, 3.06] kg.

    When applied to a DeviceMetric, it expresses the maximum deviation of values reported by the metric over the entire range of measurement.

    Accuracy is usually in the same units as the reported value. Accuracy valueQuantity units SHOULD be provided for clarity; if omitted, they are implied to be the same as the reported value's units (or the DeviceMetric units).

    Maturity: 0

    Differential View

    This structure is derived from Extension

    NameFlagsCard.TypeDescription & Constraints    Filter: doco
    Extension 0..1 Extension Absolute maximum deviation from actual value
    Extension.extension 0..0 Extension
    Extension.url 1..1 uri "http://hl7.org/fhir/StructureDefinition/quantity-accuracy"
    Extension.value[x] 0..1 Quantity Absolute maximum deviation of the reported value from the actual value
    Extension.valueQuantity
    Extension.valueQuantity.value 1..1 decimal Numerical value (with implicit precision)

    doco Documentation for this format

    Snapshot View

    NameFlagsCard.TypeDescription & Constraints    Filter: doco
    Extension 0..1 Extension Absolute maximum deviation from actual value
    Extension.id 0..1 id Unique id for inter-element referencing
    Extension.extension 0..0 Extension
    Slice: Unordered, Open by value:url

    Slicing Note: The rules on this element (including its children) apply to all the slices, but are not repeated in them
    Extension.url 1..1 uri "http://hl7.org/fhir/StructureDefinition/quantity-accuracy"
    Extension.value[x] 0..1 Quantity Absolute maximum deviation of the reported value from the actual value
    Extension.value[x].id 0..1 id Unique id for inter-element referencing
    Extension.value[x].extension 0..* Extension Additional content defined by implementations
    Slice: Unordered, Open by value:url
    Extension.value[x].value This element is included in summaries. 1..1 decimal Numerical value (with implicit precision)
    Extension.value[x].comparator This element is a modifier element. This element is included in summaries. 0..1 code < | <= | >= | > | ad - how to understand the value
    Binding: QuantityComparator (required): How the Quantity should be understood and represented.
    Extension.value[x].unit This element is included in summaries. 0..1 string Unit representation
    Extension.value[x].system This element is included in summaries. C 0..1 uri System that defines coded unit form
    Extension.value[x].code This element is included in summaries. C 0..1 code Coded form of the unit

    doco Documentation for this format

     

    Other representations of profile: CSV, Excel, Schematron

    Terminology Bindings

    Path Status Usage ValueSet Version Source
    Extension.value[x].comparator Base required QuantityComparator 📍5.0.0 FHIR Std.

    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()

    R4B

    The extension is represented a little differently in R4B:

    • Remove the extension context DeviceMetric (not for this version)
    Name Flags Card. Type Description & Constraints      Filter: doco
    Extension 0 ..1 Extension Absolute maximum deviation from actual value
    Extension. extension 0 .. 0 Extension
    Extension. url 1 .. 1 uri "http://hl7.org/fhir/StructureDefinition/quantity-accuracy"
    Extension. value[x] 0 .. 1 Quantity Absolute maximum deviation of the reported value from the actual value
    Extension. valueQuantity
    Extension.valueQuantity. value 1.. 1 decimal Numerical value (with implicit precision)

    doco Documentation for this format

    R4

    The extension is represented a little differently in R4:

    • Remove the extension context DeviceMetric (not for this version)
    Name Flags Card. Type Description & Constraints      Filter: doco
    Extension 0 ..1 Extension Absolute maximum deviation from actual value
    Extension. extension 0 .. 0 Extension
    Extension. url 1 .. 1 uri "http://hl7.org/fhir/StructureDefinition/quantity-accuracy"
    Extension. value[x] 0 .. 1 Quantity Absolute maximum deviation of the reported value from the actual value
    Extension. valueQuantity
    Extension.valueQuantity. value 1.. 1 decimal Numerical value (with implicit precision)

    doco Documentation for this format

    R3

    The extension is represented a little differently in R3:

    • Remove the extension context DeviceMetric (not for this version)
    Name Flags Card. Type Description & Constraints      Filter: doco
    Extension 0 ..1 Extension Absolute maximum deviation from actual value
    Extension. extension 0 .. 0 Extension
    Extension. url 1 .. 1 uri "http://hl7.org/fhir/StructureDefinition/quantity-accuracy"
    Extension. value[x] 0 .. 1 Quantity Absolute maximum deviation of the reported value from the actual value
    Extension. valueQuantity
    Extension.valueQuantity. value 1.. 1 decimal Numerical value (with implicit precision)

    doco Documentation for this format

    Search Parameters for this Extension

    (none found)