{
"description": "The absolute of the maximum deviation of the actual value from the reported value.\\n\\nAccuracy 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.\\n\\nWhen applied to a DeviceMetric, it expresses the maximum deviation of values reported by the metric over the entire range of measurement.\\n\\nAccuracy 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).",
"_filename": "StructureDefinition-quantity-accuracy.json",
"package_name": "hl7.fhir.uv.extensions.r4b",
"date": "2025-07-17",
"derivation": "constraint",
"publisher": "HL7 International / Orders and Observations",
"fhirVersion": "4.3.0",
"jurisdiction": [ {
"coding": [ {
"code": "001",
"system": "http://unstats.un.org/unsd/methods/m49/m49.htm"
} ]
} ],
"name": "QuantityAccuracy",
"mapping": [ {
"uri": "http://hl7.org/v3",
"name": "RIM Mapping",
"identity": "rim"
} ],
"abstract": false,
"type": "Extension",
"experimental": "false",
"resourceType": "StructureDefinition",
"title": "Quantity Accuracy",
"package_version": "5.3.0",
"extension": [ {
"url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-wg",
"valueCode": "oo"
}, {
"url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status",
"valueCode": "draft"
}, {
"url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm",
"valueInteger": 0
}, {
"url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-type-characteristics",
"valueCode": "can-bind"
} ],
"snapshot": {
"element": [ {
"constraint": [ {
"key": "ele-1",
"human": "All FHIR elements must have a @value or children unless an empty Parameters resource",
"xpath": "@value|f:*|h:div|self::f:Parameters",
"source": "http://hl7.org/fhir/StructureDefinition/Element",
"severity": "error",
"expression": "hasValue() or (children().count() > id.count()) or $this is Parameters"
}, {
"key": "ext-1",
"human": "Must have either extensions or value[x], not both",
"xpath": "exists(f:extension)!=exists(f:*[starts-with(local-name(.), 'value')])",
"source": "http://hl7.org/fhir/StructureDefinition/Extension",
"severity": "error",
"expression": "extension.exists() != value.exists()"
} ],
"path": "Extension",
"min": 0,
"definition": "Absolute maximum deviation of the actual value from the reported value, in the same unit as the reported value.",
"isModifier": false,
"short": "Absolute maximum deviation from actual value",
"max": "1",
"id": "Extension",
"condition": [ "ele-1" ],
"base": {
"max": "*",
"min": 0,
"path": "Extension"
}
}, {
"path": "Extension.id",
"min": 0,
"definition": "Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.",
"isModifier": false,
"short": "Unique id for inter-element referencing",
"mapping": [ {
"map": "n/a",
"identity": "rim"
} ],
"type": [ {
"code": "http://hl7.org/fhirpath/System.String",
"extension": [ {
"url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
"valueUrl": "id"
} ]
} ],
"representation": [ "xmlAttr" ],
"max": "1",
"id": "Extension.id",
"base": {
"max": "1",
"min": 0,
"path": "Element.id"
},
"isSummary": false
}, {
"constraint": [ {
"key": "ele-1",
"human": "All FHIR elements must have a @value or children",
"xpath": "@value|f:*|h:div",
"source": "http://hl7.org/fhir/StructureDefinition/Element",
"severity": "error",
"expression": "hasValue() or (children().count() > id.count())"
}, {
"key": "ext-1",
"human": "Must have either extensions or value[x], not both",
"xpath": "exists(f:extension)!=exists(f:*[starts-with(local-name(.), \"value\")])",
"source": "http://hl7.org/fhir/StructureDefinition/Extension",
"severity": "error",
"expression": "extension.exists() != value.exists()"
} ],
"path": "Extension.extension",
"min": 0,
"definition": "An Extension",
"isModifier": false,
"short": "Extension",
"slicing": {
"rules": "open",
"description": "Extensions are always sliced by (at least) url",
"discriminator": [ {
"path": "url",
"type": "value"
} ]
},
"type": [ {
"code": "Extension"
} ],
"max": "0",
"id": "Extension.extension",
"base": {
"max": "*",
"min": 0,
"path": "Element.extension"
},
"isSummary": false
}, {
"path": "Extension.url",
"min": 1,
"definition": "Source of the definition for the extension code - a logical name or a URL.",
"isModifier": false,
"short": "identifies the meaning of the extension",
"fixedUri": "http://hl7.org/fhir/StructureDefinition/quantity-accuracy",
"mapping": [ {
"map": "N/A",
"identity": "rim"
} ],
"type": [ {
"code": "http://hl7.org/fhirpath/System.String",
"extension": [ {
"url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
"valueUrl": "uri"
} ]
} ],
"representation": [ "xmlAttr" ],
"max": "1",
"id": "Extension.url",
"comment": "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.",
"base": {
"max": "1",
"min": 1,
"path": "Extension.url"
},
"isSummary": false
}, {
"constraint": [ {
"key": "ele-1",
"human": "All FHIR elements must have a @value or children",
"xpath": "@value|f:*|h:div",
"source": "http://hl7.org/fhir/StructureDefinition/Element",
"severity": "error",
"expression": "hasValue() or (children().count() > id.count())"
} ],
"path": "Extension.value[x]",
"min": 0,
"definition": "Value of extension - must be one of a constrained set of the data types (see [Extensibility](http://hl7.org/fhir/R4B/extensibility.html) for a list).",
"isModifier": false,
"short": "Absolute maximum deviation of the reported value from the actual value",
"mapping": [ {
"map": "N/A",
"identity": "rim"
} ],
"type": [ {
"code": "Quantity"
} ],
"max": "1",
"id": "Extension.value[x]",
"base": {
"max": "1",
"min": 0,
"path": "Extension.value[x]"
},
"isSummary": false
}, {
"path": "Extension.value[x].id",
"min": 0,
"definition": "Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.",
"isModifier": false,
"short": "Unique id for inter-element referencing",
"mapping": [ {
"map": "n/a",
"identity": "rim"
} ],
"type": [ {
"code": "http://hl7.org/fhirpath/System.String",
"extension": [ {
"url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
"valueUrl": "id"
} ]
} ],
"representation": [ "xmlAttr" ],
"max": "1",
"id": "Extension.value[x].id",
"base": {
"max": "1",
"min": 0,
"path": "Element.id"
},
"isSummary": false
}, {
"constraint": [ {
"key": "ele-1",
"human": "All FHIR elements must have a @value or children",
"xpath": "@value|f:*|h:div",
"source": "http://hl7.org/fhir/StructureDefinition/Element",
"severity": "error",
"expression": "hasValue() or (children().count() > id.count())"
}, {
"key": "ext-1",
"human": "Must have either extensions or value[x], not both",
"xpath": "exists(f:extension)!=exists(f:*[starts-with(local-name(.), \"value\")])",
"source": "http://hl7.org/fhir/StructureDefinition/Extension",
"severity": "error",
"expression": "extension.exists() != value.exists()"
} ],
"path": "Extension.value[x].extension",
"min": 0,
"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.",
"isModifier": false,
"short": "Additional content defined by implementations",
"mapping": [ {
"map": "n/a",
"identity": "rim"
} ],
"slicing": {
"rules": "open",
"description": "Extensions are always sliced by (at least) url",
"discriminator": [ {
"path": "url",
"type": "value"
} ]
},
"type": [ {
"code": "Extension"
} ],
"alias": [ "extensions", "user content" ],
"max": "*",
"id": "Extension.value[x].extension",
"comment": "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.",
"base": {
"max": "*",
"min": 0,
"path": "Element.extension"
},
"isSummary": false
}, {
"constraint": [ {
"key": "ele-1",
"human": "All FHIR elements must have a @value or children",
"xpath": "@value|f:*|h:div",
"source": "http://hl7.org/fhir/StructureDefinition/Element",
"severity": "error",
"expression": "hasValue() or (children().count() > id.count())"
} ],
"path": "Extension.value[x].value",
"requirements": "Precision is handled implicitly in almost all cases of measurement.",
"min": 1,
"definition": "The value of the measured amount. The value includes an implicit precision in the presentation of the value.",
"isModifier": false,
"short": "Numerical value (with implicit precision)",
"mapping": [ {
"map": "SN.2 / CQ - N/A",
"identity": "v2"
}, {
"map": "PQ.value, CO.value, MO.value, IVL.high or IVL.low depending on the value",
"identity": "rim"
} ],
"type": [ {
"code": "decimal"
} ],
"max": "1",
"id": "Extension.value[x].value",
"comment": "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).",
"base": {
"max": "1",
"min": 0,
"path": "Quantity.value"
},
"isSummary": true
}, {
"constraint": [ {
"key": "ele-1",
"human": "All FHIR elements must have a @value or children",
"xpath": "@value|f:*|h:div",
"source": "http://hl7.org/fhir/StructureDefinition/Element",
"severity": "error",
"expression": "hasValue() or (children().count() > id.count())"
} ],
"path": "Extension.value[x].comparator",
"requirements": "Need a framework for handling measures where the value is <5ug/L or >400mg/L due to the limitations of measuring methodology.",
"min": 0,
"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.",
"isModifier": true,
"short": "< | <= | >= | > - how to understand the value",
"mapping": [ {
"map": "SN.1 / CQ.1",
"identity": "v2"
}, {
"map": "IVL properties",
"identity": "rim"
} ],
"type": [ {
"code": "code"
} ],
"meaningWhenMissing": "If there is no comparator, then there is no modification of the value",
"binding": {
"strength": "required",
"valueSet": "http://hl7.org/fhir/ValueSet/quantity-comparator|4.3.0",
"extension": [ {
"url": "http://hl7.org/fhir/build/StructureDefinition/binding-definition",
"valueString": "How the Quantity should be understood and represented."
}, {
"url": "http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName",
"valueString": "QuantityComparator"
} ]
},
"max": "1",
"id": "Extension.value[x].comparator",
"base": {
"max": "1",
"min": 0,
"path": "Quantity.comparator"
},
"isModifierReason": "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",
"isSummary": true
}, {
"constraint": [ {
"key": "ele-1",
"human": "All FHIR elements must have a @value or children",
"xpath": "@value|f:*|h:div",
"source": "http://hl7.org/fhir/StructureDefinition/Element",
"severity": "error",
"expression": "hasValue() or (children().count() > id.count())"
} ],
"path": "Extension.value[x].unit",
"requirements": "There are many representations for units of measure and in many contexts, particular representations are fixed and required. I.e. mcg for micrograms.",
"min": 0,
"definition": "A human-readable form of the unit.",
"isModifier": false,
"short": "Unit representation",
"mapping": [ {
"map": "(see OBX.6 etc.) / CQ.2",
"identity": "v2"
}, {
"map": "PQ.unit",
"identity": "rim"
} ],
"type": [ {
"code": "string"
} ],
"extension": [ {
"url": "http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable",
"valueBoolean": true
}, {
"url": "http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable",
"valueBoolean": true
} ],
"max": "1",
"id": "Extension.value[x].unit",
"base": {
"max": "1",
"min": 0,
"path": "Quantity.unit"
},
"isSummary": true
}, {
"constraint": [ {
"key": "ele-1",
"human": "All FHIR elements must have a @value or children",
"xpath": "@value|f:*|h:div",
"source": "http://hl7.org/fhir/StructureDefinition/Element",
"severity": "error",
"expression": "hasValue() or (children().count() > id.count())"
} ],
"path": "Extension.value[x].system",
"requirements": "Need to know the system that defines the coded form of the unit.",
"min": 0,
"definition": "The identification of the system that provides the coded form of the unit.",
"isModifier": false,
"short": "System that defines coded unit form",
"mapping": [ {
"map": "(see OBX.6 etc.) / CQ.2",
"identity": "v2"
}, {
"map": "CO.codeSystem, PQ.translation.codeSystem",
"identity": "rim"
} ],
"type": [ {
"code": "uri"
} ],
"max": "1",
"id": "Extension.value[x].system",
"condition": [ "qty-3" ],
"base": {
"max": "1",
"min": 0,
"path": "Quantity.system"
},
"isSummary": true
}, {
"constraint": [ {
"key": "ele-1",
"human": "All FHIR elements must have a @value or children",
"xpath": "@value|f:*|h:div",
"source": "http://hl7.org/fhir/StructureDefinition/Element",
"severity": "error",
"expression": "hasValue() or (children().count() > id.count())"
} ],
"path": "Extension.value[x].code",
"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.",
"min": 0,
"definition": "A computer processable form of the unit in some unit representation system.",
"isModifier": false,
"short": "Coded form of the unit",
"mapping": [ {
"map": "(see OBX.6 etc.) / CQ.2",
"identity": "v2"
}, {
"map": "PQ.code, MO.currency, PQ.translation.code",
"identity": "rim"
} ],
"type": [ {
"code": "code"
} ],
"extension": [ {
"url": "http://hl7.org/fhir/build/StructureDefinition/no-binding",
"valueBoolean": true
} ],
"max": "1",
"id": "Extension.value[x].code",
"comment": "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.",
"base": {
"max": "1",
"min": 0,
"path": "Quantity.code"
},
"isSummary": true
} ],
"extension": [ {
"url": "http://hl7.org/fhir/tools/StructureDefinition/snapshot-base-version",
"valueString": "4.3.0"
} ]
},
"status": "draft",
"id": "69e9b1e8-15c1-4549-ab28-29832dffa124",
"kind": "complex-type",
"url": "http://hl7.org/fhir/StructureDefinition/quantity-accuracy",
"context": [ {
"type": "element",
"expression": "Quantity"
}, {
"type": "element",
"extension": [ {
"url": "http://hl7.org/fhir/StructureDefinition/version-specific-use",
"extension": [ {
"url": "startFhirVersion",
"valueCode": "5.0"
} ]
} ],
"expression": "DeviceMetric"
} ],
"version": "5.3.0",
"differential": {
"element": [ {
"id": "Extension",
"max": "1",
"path": "Extension",
"short": "Absolute maximum deviation from actual value",
"definition": "Absolute maximum deviation of the actual value from the reported value, in the same unit as the reported value."
}, {
"id": "Extension.extension",
"max": "0",
"path": "Extension.extension"
}, {
"id": "Extension.url",
"path": "Extension.url",
"fixedUri": "http://hl7.org/fhir/StructureDefinition/quantity-accuracy"
}, {
"id": "Extension.value[x]",
"path": "Extension.value[x]",
"type": [ {
"code": "Quantity"
} ],
"short": "Absolute maximum deviation of the reported value from the actual value"
}, {
"id": "Extension.valueQuantity.value",
"min": 1,
"path": "Extension.valueQuantity.value"
} ]
},
"contact": [ {
"telecom": [ {
"value": "http://www.hl7.org/Special/committees/orders",
"system": "url"
} ]
} ],
"baseDefinition": "http://hl7.org/fhir/StructureDefinition/Extension"
}