Accuracy
type: StructureDefinition
node role: treeRoot
id:
  v: Accuracy
language:
  v: en
text:
  status:
    v: extensions
  div:
    v: Generated Narrative: StructureDefinition Accuracy Name Flags Card. Type Description & Constraints Extension 0..1 Extension Numeric Accuracy #xD; extension 0..0 Extension #xD; url 1..1 uri "http://hl7.org/fhir/uv/phd/StructureDefinition/Accuracy" #xD; value[x] 1..1 Quantity Value of extension #xD; value 0..1 decimal Numerical value (with implicit precision) #xD; unit 0..1 string Unit representation #xD; Documentation for this format
extension:
  url:
    v: http://hl7.org/fhir/StructureDefinition/structuredefinition-type-characteristics
    l: structuredefinition-type-characteristics
  value: Code
    v: can-bind
extension:
  url:
    v: http://hl7.org/fhir/StructureDefinition/structuredefinition-wg
    l: structuredefinition-wg
  value: Code
    v: dev
extension:
  url:
    v: http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm
    l: structuredefinition-fmm
  value: Integer
    v: 1
    extension:
      url:
        v: http://hl7.org/fhir/StructureDefinition/structuredefinition-conformance-derivedFrom
        l: structuredefinition-conformance-derivedFrom
      value: Canonical
        v: http://hl7.org/fhir/uv/phd/ImplementationGuide/hl7.fhir.uv.phd
        l: hl7.fhir.uv.phd
extension:
  url:
    v: http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status
    l: structuredefinition-standards-status
  value: Code
    v: trial-use
    extension:
      url:
        v: http://hl7.org/fhir/StructureDefinition/structuredefinition-conformance-derivedFrom
        l: structuredefinition-conformance-derivedFrom
      value: Canonical
        v: http://hl7.org/fhir/uv/phd/ImplementationGuide/hl7.fhir.uv.phd
        l: hl7.fhir.uv.phd
url:
  v: http://hl7.org/fhir/uv/phd/StructureDefinition/Accuracy
  l: Accuracy
identifier:
  system:
    v: urn:ietf:rfc:3986
    l: 3986
  value:
    v: urn:oid:2.16.840.1.113883.4.642.40.73.42.1
version:
  v: 3.0.0-draft
name:
  v: Accuracy
title:
  v: Numeric Accuracy
status:
  v: active
date:
  v: 2026-08-20T11:48:35+00:00
publisher:
  v: HL7 International / Devices
contact:
  name:
    v: HL7 International / Devices
  telecom:
    system:
      v: url
    value:
      v: http://www.hl7.org/Special/committees/healthcaredevices
description:
  v: The accuracy of a measurable quantity.
jurisdiction:
  coding:
    system:
      v: http://unstats.un.org/unsd/methods/m49/m49.htm
      l: m49.htm
    code:
      v: 001
fhir version:
  v: 6.0.0-ballot5
mapping:
  identity:
    v: rim
  uri:
    v: http://hl7.org/v3
    l: v3
  name:
    v: RIM Mapping
kind:
  v: complex-type
abstract:
  v: false
context:
  type:
    v: element
  expression:
    v: Observation
context:
  type:
    v: element
  expression:
    v: DeviceMetric
context:
  type:
    v: element
  expression:
    v: Observation.component
type:
  v: Extension
  l: Extension
base definition:
  v: http://hl7.org/fhir/StructureDefinition/Extension
  l: Extension
derivation:
  v: constraint
snapshot:
  extension:
    url:
      v: http://hl7.org/fhir/tools/StructureDefinition/snapshot-base-version
      l: snapshot-base-version
    value: String
      v: 6.0.0-ballot5
  element:
    id:
      v: Extension
    path:
      v: Extension
    short:
      v: Numeric Accuracy
    definition:
      v: The accuracy of a measurable quantity.
    min:
      v: 0
    max:
      v: 1
    base:
      path:
        v: Extension
      min:
        v: 0
      max:
        v: *
    constraint:
      key:
        v: ele-1
      severity:
        v: error
      human:
        v: All FHIR elements must have a @value or children
      expression:
        v: hasValue() or (children().count() > id.count())
      source:
        v: http://hl7.org/fhir/StructureDefinition/Element
        l: Element
    constraint:
      key:
        v: ext-1
      severity:
        v: error
      human:
        v: Must have either extensions or value[x], not both
      expression:
        v: extension.exists() != value.exists()
      source:
        v: http://hl7.org/fhir/StructureDefinition/Extension
        l: Extension
    is modifier:
      v: false
  element:
    id:
      v: Extension.id
    path:
      v: Extension.id
    representation:
      v: xmlAttr
    short:
      v: Unique id for inter-element referencing
    definition:
      v: Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
    min:
      v: 0
    max:
      v: 1
    base:
      path:
        v: Element.id
      min:
        v: 0
      max:
        v: 1
    type:
      extension:
        value: Url
      code:
        v: http://hl7.org/fhirpath/System.String
        l: System.String

Url
v: string
l: string

v: ele-1

v: false

v: false

identity:
  v: rim
map:
  v: n/a

id:
  v: Extension.extension
path:
  v: Extension.extension
slicing:
  discriminator:
    type:
      v: value
    path:
      v: url
  description:
    v: Extensions are always sliced by (at least) url
  rules:
    v: open
short:
  v: Extension
definition:
  v: An Extension
min:
  v: 0
max:
  v: 0
base:
  path:
    v: Element.extension
  min:
    v: 0
  max:
    v: *
type:
  code:
    v: Extension
    l: Extension
constraint:
  key:
    v: ele-1
  severity:
    v: error
  human:
    v: All FHIR elements must have a @value or children
  expression:
    v: hasValue() or (children().count() > id.count())
  source:
    v: http://hl7.org/fhir/StructureDefinition/Element
    l: Element
is modifier:
  v: false
is summary:
  v: false

id:
  v: Extension.url
path:
  v: Extension.url
representation:
  v: xmlAttr
short:
  v: identifies the meaning of the extension
definition:
  v: Source of the definition for the extension code - a logical name or a URL.
comment:
  v: The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.
min:
  v: 1
max:
  v: 1
base:
  path:
    v: Extension.url
  min:
    v: 1
  max:
    v: 1
type:
  extension:
    url:
      v: http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type
      l: structuredefinition-fhir-type
    value: Url
      v: uri
      l: uri
  code:
    v: http://hl7.org/fhirpath/System.String
    l: System.String
fixed: Uri
  v: http://hl7.org/fhir/uv/phd/StructureDefinition/Accuracy
  l: Accuracy
is modifier:
  v: false
is summary:
  v: true
mapping:
  identity:
    v: rim
  map:
    v: N/A

id:
  v: Extension.value[x]
path:
  v: Extension.value[x]
short:
  v: Value of extension
definition:
  v: Value of extension - must be one of a constrained set of the data types (see [Extensibility](http://build.fhir.org/extensibility.html) for a list).
min:
  v: 1
max:
  v: 1
base:
  path:
    v: Extension.value[x]
  min:
    v: 0
  max:
    v: 1
type:
  code:
    v: Quantity
    l: Quantity
condition:
  v: ext-1
constraint:
  key:
    v: ele-1
  severity:
    v: error
  human:
    v: All FHIR elements must have a @value or children
  expression:
    v: hasValue() or (children().count() > id.count())
  source:
    v: http://hl7.org/fhir/StructureDefinition/Element
    l: Element
is modifier:
  v: false
is summary:
  v: true
mapping:
  identity:
    v: rim
  map:
    v: N/A

id:
  v: Extension.value[x].id
path:
  v: Extension.value[x].id
representation:
  v: xmlAttr
short:
  v: Unique id for inter-element referencing
definition:
  v: Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
min:
  v: 0
max:
  v: 1
base:
  path:
    v: Element.id
  min:
    v: 0
  max:
    v: 1
type:
  extension:
    url:
      v: http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type
      l: structuredefinition-fhir-type
    value: Url
      v: string
      l: string
  code:
    v: http://hl7.org/fhirpath/System.String
    l: System.String
condition:
  v: ele-1
is modifier:
  v: false
is summary:
  v: false
mapping:
  identity:
    v: rim
  map:
    v: n/a

id:
  v: Extension.value[x].extension
path:
  v: Extension.value[x].extension
slicing:
  discriminator:
    type:
      v: value
    path:
      v: url
  description:
    v: Extensions are always sliced by (at least) url
  rules:
    v: open
short:
  v: Additional content defined by implementations
definition:
  v: 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 managable, 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.
comment:
  v: 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.
alias:
  v: extensions
alias:
  v: user content
min:
  v: 0
max:
  v: *
base:
  path:
    v: Element.extension
  min:
    v: 0
  max:
    v: *
type:
  code:
    v: Extension
    l: Extension
constraint:
  key:
    v: ele-1
  severity:
    v: error
  human:
    v: All FHIR elements must have a @value or children
  expression:
    v: hasValue() or (children().count() > id.count())
  source:
    v: http://hl7.org/fhir/StructureDefinition/Element
    l: Element
is modifier:
  v: false
is summary:
  v: false
mapping:
  identity:
    v: rim
  map:
    v: n/a

id:
  v: Extension.value[x].value
path:
  v: Extension.value[x].value
short:
  v: Numerical value (with implicit precision)
definition:
  v: The actual accuracy value should positive.
comment:
  v: 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).
requirements:
  v: Precision is handled implicitly in almost all cases of measurement.
min:
  v: 0
max:
  v: 1
base:
  path:
    v: Quantity.value
  min:
    v: 0
  max:
    v: 1
type:
  code:
    v: decimal
    l: decimal
constraint:
  key:
    v: ele-1
  severity:
    v: error
  human:
    v: All FHIR elements must have a @value or children
  expression:
    v: hasValue() or (children().count() > id.count())
  source:
    v: http://hl7.org/fhir/StructureDefinition/Element
    l: Element
is modifier:
  v: false
is summary:
  v: true
mapping:
  identity:
    v: v2
  map:
    v: SN.2 / CQ - N/A
mapping:
  identity:
    v: rim
  map:
    v: PQ.value, CO.value, MO.value, IVL.high or IVL.low depending on the value

id:
  v: Extension.value[x].comparator
path:
  v: Extension.value[x].comparator
short:
  v: < | <= | >= | > | ~ | ad - how to understand the value
definition:
  v: How the value should be understood and represented - whether the actual value is greater than, less than, or approximately equal to the stated value due to measurement issues; e.g. if the comparator is "<" , then the real value is < stated value.
requirements:
  v: Need a framework for handling measures where the value is <5ug/L or >400mg/L due to the limitations of measuring methodology.
min:
  v: 0
max:
  v: 1
base:
  path:
    v: Quantity.comparator
  min:
    v: 0
  max:
    v: 1
type:
  code:
    v: code
    l: code
meaning when missing:
  v: If there is no comparator, then there is no modification of the value
constraint:
  key:
    v: ele-1
  severity:
    v: error
  human:
    v: All FHIR elements must have a @value or children
  expression:
    v: hasValue() or (children().count() > id.count())
  source:
    v: http://hl7.org/fhir/StructureDefinition/Element
    l: Element
is modifier:
  v: true
is modifier reason:
  v: 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
is summary:
  v: true
binding:
  extension:
    url:
      v: http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName
      l: elementdefinition-bindingName
    value: String
      v: QuantityComparator
  strength:
    v: required
  description:
    v: How the Quantity should be understood and represented.
  value set:
    v: http://hl7.org/fhir/ValueSet/quantity-comparator|6.0.0-ballot5
    l: http://hl7.org/fhir/ValueSet/quantity-comparator
mapping:
  identity:
    v: v2
  map:
    v: SN.1 / CQ.1
mapping:
  identity:
    v: rim
  map:
    v: IVL properties

id:
  v: Extension.value[x].unit
extension:
  url:
    v: http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable
    l: elementdefinition-translatable
  value: Boolean
    v: true
path:
  v: Extension.value[x].unit
short:
  v: Unit representation
definition:
  v: The unit should be the same as the unit of the quantity this applies to.
requirements:
  v: There are many representations for units of measure and in many contexts, particular representations are fixed and required. I.e. mcg for micrograms.
min:
  v: 0
max:
  v: 1
base:
  path:
    v: Quantity.unit
  min:
    v: 0
  max:
    v: 1
type:
  code:
    v: string
    l: string
constraint:
  key:
    v: ele-1
  severity:
    v: error
  human:
    v: All FHIR elements must have a @value or children
  expression:
    v: hasValue() or (children().count() > id.count())
  source:
    v: http://hl7.org/fhir/StructureDefinition/Element
    l: Element
is modifier:
  v: false
is summary:
  v: true
mapping:
  identity:
    v: v2
  map:
    v: (see OBX.6 etc.) / CQ.2
mapping:
  identity:
    v: rim
  map:
    v: PQ.unit

id:
  v: Extension.value[x].system
path:
  v: Extension.value[x].system
short:
  v: System that defines coded unit form
definition:
  v: The identification of the system that provides the coded form of the unit.
requirements:
  v: Need to know the system that defines the coded form of the unit.
min:
  v: 0
max:
  v: 1
base:
  path:
    v: Quantity.system
  min:
    v: 0
  max:
    v: 1
type:
  code:
    v: uri
    l: uri
condition:
  v: qty-3
constraint:
  key:
    v: ele-1
  severity:
    v: error
  human:
    v: All FHIR elements must have a @value or children
  expression:
    v: hasValue() or (children().count() > id.count())
  source:
    v: http://hl7.org/fhir/StructureDefinition/Element
    l: Element
is modifier:
  v: false
is summary:
  v: true
mapping:
  identity:
    v: v2
  map:
    v: (see OBX.6 etc.) / CQ.2
mapping:
  identity:
    v: rim
  map:
    v: CO.codeSystem, PQ.translation.codeSystem

id:
  v: Extension.value[x].code
path:
  v: Extension.value[x].code
short:
  v: Coded form of the unit
definition:
  v: A computer processable form of the unit in some unit representation system.
comment:
  v: 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.
requirements:
  v: 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.
min:
  v: 0
max:
  v: 1
base:
  path:
    v: Quantity.code
  min:
    v: 0
  max:
    v: 1
type:
  code:
    v: code
    l: code
condition:
  v: qty-3
constraint:
  key:
    v: ele-1
  severity:
    v: error
  human:
    v: All FHIR elements must have a @value or children
  expression:
    v: hasValue() or (children().count() > id.count())
  source:
    v: http://hl7.org/fhir/StructureDefinition/Element
    l: Element
is modifier:
  v: false
is summary:
  v: true
mapping:
  identity:
    v: v2
  map:
    v: (see OBX.6 etc.) / CQ.2
mapping:
  identity:
    v: rim
  map:
    v: PQ.code, MO.currency, PQ.translation.code

element:
  id:
    v: Extension
  path:
    v: Extension
  short:
    v: Numeric Accuracy
  definition:
    v: The accuracy of a measurable quantity.
  max:
    v: 1
element:
  id:
    v: Extension.extension
  path:
    v: Extension.extension
  max:
    v: 0
element:
  id:
    v: Extension.url
  path:
    v: Extension.url
  fixed: Uri
    v: http://hl7.org/fhir/uv/phd/StructureDefinition/Accuracy
    l: Accuracy
element:
  id:
    v: Extension.value[x]
  path:
    v: Extension.value[x]
  min:
    v: 1
  type:
    code:
      v: Quantity
      l: Quantity
element:
  id:
    v: Extension.value[x].value
  path:
    v: Extension.value[x].value
  definition:
    v: The actual accuracy value should positive.
element:
  id:
    v: Extension.value[x].unit
  path:
    v: Extension.value[x].unit
  definition:
    v: The unit should be the same as the unit of the quantity this applies to.