type: datatypedatatype: ElementDefinition

ElementDefinition

Elements

ElementDefinition.path [1..1]: string The path identifies the element and is expressed as a "."-separated list of ancestor elements, beginning with the name of the resource or extension
ElementDefinition.representation [0..*]: code Codes that define how this element is represented in instances, when the deviation varies from the normal case. No extensions are allowed on elements with a representation of 'xmlAttr', no matter what FHIR serialization format is used.
ElementDefinition.sliceName [0..1]: string The name of this element definition slice, when slicing is working. The name must be a token with no dots or spaces. This is a unique name referring to a specific set of constraints applied to this element, used to provide a name to different slices of the same element
ElementDefinition.sliceIsConstraining [0..1]: boolean If true, indicates that this slice definition is constraining a slice definition with the same name in an inherited profile. If false, the slice is not overriding any slice in an inherited profile. If missing, the slice might or might not be overriding a slice in an inherited profile, depending on the sliceName
ElementDefinition.label [0..1]: string A single preferred label which is the text to display beside the element indicating its meaning or to use to prompt for the element in a user display or form.
ElementDefinition.code [0..*]: Coding A code that has the same meaning as the element in a particular terminology.
ElementDefinition.slicing [0..1]: - Indicates that the element is sliced into a set of alternative definitions (i.e. in a structure definition, there are multiple different constraints on a single element in the base resource). Slicing can be used in any resource that has cardinality ..* on the base resource, or any resource with a choice of types. The set of slices is any elements that come after this in the element sequence that have the same path, until a shorter path occurs (the shorter path terminates the set)
ElementDefinition.short [0..1]: string A concise description of what this element means (e.g. for use in autogenerated summaries)
ElementDefinition.definition [0..1]: markdown Provides a complete explanation of the meaning of the data element for human readability. For the case of elements derived from existing elements (e.g. constraints), the definition SHALL be consistent with the base definition, but convey the meaning of the element in the particular context of use of the resource. (Note: The text you are reading is specified in ElementDefinition.definition)
ElementDefinition.comment [0..1]: markdown Explanatory notes and implementation guidance about the data element, including notes about how to use the data properly, exceptions to proper use, etc. (Note: The text you are reading is specified in ElementDefinition.comment)
ElementDefinition.requirements [0..1]: markdown This element is for traceability of why the element was created and why the constraints exist as they do. This may be used to point to source materials or specifications that drove the structure of this element.
ElementDefinition.alias [0..*]: string Identifies additional names by which this element might also be known
ElementDefinition.min [0..1]: unsignedInt The minimum number of times this element SHALL appear in the instance
ElementDefinition.max [0..1]: string The maximum number of times this element is permitted to appear in the instance
ElementDefinition.base [0..1]: - Information about the base definition of the element, provided to make it unnecessary for tools to trace the deviation of the element through the derived and related profiles. When the element definition is not the original definition of an element - e.g. either in a constraint on another type, or for elements from a super type in a snap shot - then the information in provided in the element definition may be different to the base definition. On the original definition of the element, it will be same
ElementDefinition.contentReference [0..1]: uri Identifies an element defined elsewhere in the definition whose content rules should be applied to the current element. ContentReferences bring across all the rules that are in the ElementDefinition for the element, including definitions, cardinality constraints, bindings, invariants etc.
ElementDefinition.type [0..*]: =TypeRef The data type or resource that the value of this element is permitted to be
ElementDefinition.defaultValue[x] [0..1]: * The value that should be used if there is no value stated in the instance (e.g. 'if not otherwise specified, the abstract is false')
ElementDefinition.meaningWhenMissing [0..1]: markdown The Implicit meaning that is to be understood when this element is missing (e.g. 'when this element is missing, the period is ongoing')
ElementDefinition.orderMeaning [0..1]: string If present, indicates that the order of the repeating element has meaning and describes what that meaning is. If absent, it means that the order of the element has no meaning
ElementDefinition.fixed[x] [0..1]: * Specifies a value that SHALL be exactly the value for this element in the instance, if present. For purposes of comparison, non-significant whitespace is ignored, and all values must be an exact match (case and accent sensitive). Missing elements/attributes must also be missing.
ElementDefinition.pattern[x] [0..1]: * Specifies a value that each occurrence of the element in the instance SHALL follow - that is, any value in the pattern must be found in the instance, if the element has a value. Other additional values may be found too. This is effectively constraint by example. When pattern[x] is used to constrain a primitive, it means that the value provided in the pattern[x] must match the instance value exactly. When an element within a pattern[x] is used to constrain an array, it means that each element provided in the pattern[x] must (recursively) match at least one element from the instance array. When pattern[x] is used to constrain a complex object, it means that each property in the pattern must be present in the complex object, and its value must recursively match -- i.e., 1. If primitive: it must match exactly the pattern value 2. If a complex object: it must match (recursively) the pattern value 3. If an array: it must match (recursively) the pattern value If a pattern[x] is declared on a repeating element, the pattern applies to all repetitions. If the desire is for a pattern to apply to only one element or a subset of elements, slicing must be used. See Examples of Patterns for examples of pattern usage and the effect it will have
ElementDefinition.example [0..*]: - A sample value for this element demonstrating the type of information that would typically be found in the element
ElementDefinition.minValue[x] [0..1]: date | dateTime | instant | time | decimal | integer | integer64| positiveInt | unsignedInt | Quantity The minimum allowed value for the element. The value is inclusive. This is allowed for the types date, dateTime, instant, time, decimal, integer, and Quantity
ElementDefinition.maxValue[x] [0..1]: date | dateTime | instant | time | decimal | integer | integer64 | positiveInt | unsignedInt | Quantity The maximum allowed value for the element. The value is inclusive. This is allowed for the types date, dateTime, instant, time, decimal, integer, and Quantity
ElementDefinition.maxLength [0..1]: integer Indicates the maximum length in characters that is permitted to be present in conformant instances and which is expected to be supported by conformant consumers that support the element. maxLength SHOULD only be used on primitive data types that have a have a length (see Tupe Characteristics and [[[http://hl7.org/fhir/StructureDefinition/structuredefinition-type-characteristics]]])
ElementDefinition.condition [0..*]: id A reference to an invariant that may make additional statements about the cardinality or value in the instance
ElementDefinition.constraint [0..*]: - Formal constraints such as co-occurrence and other constraints that can be computationally evaluated within the context of the instance
ElementDefinition.mustHaveValue [0..1]: boolean Specifies for a primitive data type that the value of the data type cannot be replaced by an extension
ElementDefinition.valueAlternatives [0..*]: canonical(StructureDefinition) Specifies a list of extensions that can appear in place of a primitive value
ElementDefinition.mustSupport [0..1]: boolean If true, implementations that produce or consume resources SHALL provide "support" for the element in some meaningful way. Note that this is being phased out and replaced by obligations (see below). If false, the element may be ignored and not supported. If false, whether to populate or use the data element in any way is at the discretion of the implementation
ElementDefinition.isModifier [0..1]: boolean If true, the value of this element affects the interpretation of the element or resource that contains it, and the value of the element cannot be ignored. Typically, this is used for status, negation and qualification codes. The effect of this is that the element cannot be ignored by systems: they SHALL either recognize the element and process it, and/or a pre-determination has been made that it is not relevant to their particular system. When used on the root element in an extension definition, this indicates whether or not the extension is a modifier extension
ElementDefinition.isModifierReason [0..1]: string Explains how that element affects the interpretation of the resource or element that contains it
ElementDefinition.isSummary [0..1]: boolean Whether the element should be included if a client requests a search with the parameter _summary=true
ElementDefinition.binding [0..1]: =ElementDefinitionBinding Binds to a value set if this element is coded (code, Coding, CodeableConcept, Quantity), or the data types (string, uri)
ElementDefinition.mapping [0..*]: - Identifies a concept from an external specification that roughly corresponds to this element

Aliases

ElementDefinition.definition: Description
ElementDefinition.alias: synonym, other name

Bindings

ElementDefinition.representation: PropertyRepresentation | strength: code list | reference: #property-representation
ElementDefinition.code: ElementDefinitionCode | strength: value set | reference: http://loinc.org/vs

Invariants

ElementDefinition.path: 19
ElementDefinition.path: 20
ElementDefinition.sliceName: 22
ElementDefinition.sliceName: 16
ElementDefinition.type: 13
ElementDefinition.type: 7
ElementDefinition.type: 6
ElementDefinition.type: 11
ElementDefinition.type: 5
ElementDefinition.defaultValue[x]: 15
ElementDefinition.defaultValue[x]: 5
ElementDefinition.fixed[x]: 5
ElementDefinition.fixed[x]: 6
ElementDefinition.fixed[x]: 8
ElementDefinition.fixed[x]: 24
ElementDefinition.pattern[x]: 5
ElementDefinition.pattern[x]: 7
ElementDefinition.pattern[x]: 8
ElementDefinition.binding: 11
ElementDefinition.binding: 5

Requirements

ElementDefinition.sliceName: May also be used for code generation purposes
ElementDefinition.sliceIsConstraining: Allows detection of a situation where an ancestor profile adds or removes slicing with the same name where that might impact the child profile
ElementDefinition.code: Links the meaning of an element to an external terminology, and is very useful for searching and indexing
ElementDefinition.definition: To allow a user to state the usage of an element in a particular context
ElementDefinition.alias: Allows for better easier recognition of the element by multiple communities, including international communities
ElementDefinition.mustSupport: Allows a profile to set expectations for system capabilities beyond merely respecting cardinality constraints
ElementDefinition.isModifier: Allows elements to be introduced into a specification that can't safely be ignored by applications that don't recognize them
ElementDefinition.isSummary: Allow clients to search through large resources quickly
ElementDefinition.mapping: Provides guidance to implementers familiar with or converting content from other specifications

Comments

ElementDefinition.representation: In resources, this is rarely used except for special cases where the representation deviates from the normal, and can only be done in the base standard (and profiles must reproduce what the base standard does). This element is used quite commonly in Logical models when the logical models represent a specific serialization format (e.g. CDA, v2 etc.)
ElementDefinition.sliceName: The name SHALL be unique within the structure within the context of the constrained resource element. (Though to avoid confusion, uniqueness across all elements is recommended.)
ElementDefinition.sliceIsConstraining: If set to true, an ancestor profile SHALL have a slicing definition with this name. If set to false, no ancestor profile is permitted to have a slicing definition with this name.
ElementDefinition.label: See also the extension [[[http://hl7.org/fhir/StructureDefinition/elementdefinition-question]]]
ElementDefinition.code: The concept SHALL be properly aligned with the data element definition and other constraints, as defined in the code system, including relationships, of any code listed here. Where multiple codes exist in a terminology that could correspond to the data element, the most granular code(s) should be selected, so long as they are not more restrictive than the data element itself. The mappings may be used to provide more or less granular or structured equivalences in the code system. This is used for both mapping to formal terminologies as well as to informal collections of data elements provided they can be treated as a 'system' (i.e. a single namespace with a canonical URI). For mappings to more complex structures not identifiable with a single id, use the ElementDefinition.mapping structure.
ElementDefinition.slicing: The first element in the sequence, the one that carries the slicing, is the definition that applies to all the slices. This is based on the unconstrained element, but can apply any constraints as appropriate. This may include the common constraints on the children of the element
ElementDefinition.short: It is easy for a different short definition to change the meaning of an element and this can have nasty downstream consequences. Please be careful when providing short definitions in a profile
ElementDefinition.definition: It is easy for a different definition to change the meaning of an element and this can have nasty downstream consequences. Please be careful when providing definitions in a profile
ElementDefinition.comment: If it is possible to capture usage rules using constraints, that mechanism should be used in preference to this element
ElementDefinition.requirements: This element does not describe the usage of the element (that's done in comments), rather it's for traceability of why the element is either needed or why the constraints exist as they do. This may be used to point to source materials or specifications that drove the structure of this data element
ElementDefinition.base: The base information does not carry any information that could not be determined from the path and related profiles, but making this determination requires both that the related profiles are available, and that the algorithm to determine them be available. For tooling simplicity, the base information must always be populated in element definitions in snap shots, even if it is the same
ElementDefinition.contentReference: ContentReferences can only be defined in specializations, not constrained types, and they cannot be changed and always reference the non-constrained definition
ElementDefinition.type: The Type of the element can be left blank in a differential constraint, in which case the type is inherited from the resource. Abstract types are not permitted to appear as a type when multiple types are listed. (I.e. Abstract types cannot be part of a choice)
ElementDefinition.defaultValue[x]: Specifying a default value means that the property can never been unknown - it must always have a value. Further, the default value can never be changed, or changed in constraints on content models. Defining default values creates many difficulties in implementation (e.g. when is a value missing?). For these reasons, default values are (and should be) used extremely sparingly. No default values are ever defined in the FHIR specification, nor can they be defined in constraints ("profiles") on data types or resources. This element only exists so that default values may be defined in logical models
ElementDefinition.meaningWhenMissing: Implicit meanings for missing values can only be specified on a resource, data type, or extension definition, and never in a profile that applies to one of these. An implicit meaning for a missing value can never be changed, and specifying one has the consequence that constraining its use in profiles eliminates use cases as possibilities, not merely moving them out of scope
ElementDefinition.orderMeaning: This element can only be asserted on repeating elements and can only be introduced when defining resources or data types. It can be further refined profiled elements but if absent in the base type, a profile cannot assert meaning
ElementDefinition.fixed[x]: This is not recommended for Coding and CodeableConcept since these often have highly contextual properties such as version or display
ElementDefinition.pattern[x]: Mostly used for fixing values of CodeableConcept. In general, pattern[x] is not intended for use with primitive types, where is has the same meaning as fixed[x]
ElementDefinition.example: Examples will most commonly be present for data where it's not implicitly obvious from either the data type or value set what the values might be. (I.e. Example values for dates or quantities would generally be unnecessary.) If the example value is fully populated, the publication tool can generate an instance automatically.
ElementDefinition.minValue[x]: Except for date/date/instant, the type of the minValue[x] SHALL be the same as the specified type of the element. For the date/dateTime/instant values, the type of minValue[x] SHALL be either the same, or a Duration which specifies a relative time limit to the current time. The duration value is positive, and is subtracted from the current clock to determine the minimum allowable value. A minimum value for a Quantity is interpreted as a canonical minimum - e.g. you cannot provide 100mg if the minimum value is 10g.
ElementDefinition.maxValue[x]: Except for date/date/instant, the type of the maxValue[x] SHALL be the same as the specified type of the element. For the date/dateTime/instant values, the type of maxValue[x] SHALL be either the same, or a Duration which specifies a relative time limit to the current time. The duration value is positive, and is added to the current clock to determine the maximum allowable value. A maximum value for a Quantity is interpreted as a canonical maximum - e.g. you cannot provide 10g if the maximum value is 50mg.
ElementDefinition.maxLength: Receivers are not required to reject instances that exceed the maximum length. The full length could be stored. In some cases, data might be truncated, though truncation should be undertaken with care and an understanding of the consequences of doing so. If not specified, there is no conformance expectation for length support
ElementDefinition.constraint: Constraints should be declared on the "context" element - the lowest element in the hierarchy that is common to all nodes referenced by the constraint
ElementDefinition.mustHaveValue: Typical extensions that can be provided in place of a the value are [[[http://hl7.org/fhir/StructureDefinition/data-absent-reason]]], [[[http://hl7.org/fhir/StructureDefinition/iso21090-nullFlavor]]], [[[http://hl7.org/fhir/StructureDefinition/originalText]]], and [[[http://hl7.org/fhir/StructureDefinition/cqf-expression]]]. Note that this element has no meaning when a value is provided, and extensions can be provided in addition to a value
ElementDefinition.valueAlternatives: If mustHaveValue is true, then this element should not be present, since no extensions are allowed in place of the value. Note that this element has no impact if the value is present. When valueAlternatives is present, it means that if the element is present, it SHALL have either a value or at least one of the listed extensions. This element is only permitted on elements with primitive types.
ElementDefinition.mustSupport: "Something meaningful" is context dependent and impossible to describe in the base FHIR specification. For this reason, the mustSupport flag is never set to true by the FHIR specification itself - it is only set to true in profiles. A profile on a type can always make mustSupport = true if it is false in the base type but cannot make mustSupport = false if it is true in the base type. This is done in Resource Profiles, where the profile labels an element as mustSupport=true. When a profile does this, it SHALL also make clear exactly what kind of "support" is required, as this can mean many things. Note that an element that has the property IsModifier is not necessarily a "key" element (e.g. one of the important elements to make use of the resource), nor is it automatically mustSupport - however both of these things are more likely to be true for IsModifier elements than for other elements.
ElementDefinition.isModifier: Only the definition of an element can set IsModifier true - either the specification itself or where an extension is originally defined. Once set, it cannot be changed in derived profiles (except in the special case of the defining a new extension). An element/extension that has isModifier=true SHOULD also have a minimum cardinality of 1, so that there is no lack of clarity about what to do if it is missing. If it can be missing, the definition SHALL make the meaning of a missing element clear. See further discussion in the conformance rules section
ElementDefinition.isSummary: Some resources include a set of simple metadata, and some very large data. This element is used to reduce the quantity of data returned in searches. Note that servers may pre-cache summarized resources for optimal performance. When a request is made with _summary=true, serializers only include elements marked as 'isSummary = true'. With a few exceptions (listed below), all datatype properties are included in the summary form. In resource and datatype definitions, if an element has a descendant within the same StructureDefinition marked as isSummary=true or if it satisfies both of the following conditions, it must be marked as isSummary=true: * is at the root or has a parent that is 'mustSupport' * has a minimum cardinality of 1 or is a modifier element The following datatype properties are exceptions, and are not marked as isSummary: * Attachment.data * Signature.data, Signature.targetFormat, Signature.sigFormat * Narrative.status, Narrative.div * SampledData.data
ElementDefinition.binding: For a CodeableConcept, when no codes are allowed - only text, use a binding of strength "required" with a description explaining that no coded values are allowed and what sort of information to put in the "text" element.
ElementDefinition.mapping: Mappings are not necessarily specific enough for safe translation. Note that ElementDefinition.code can provide a mapping to terminologies or other simple data element collections.

Order and Missing Meaning

ElementDefinition.valueAlternatives: Missing: If this element is missing, then any extension can be used if its context is appropriate
ElementDefinition.mustSupport: Missing: In a base type, where the element is being defined for the first time, the element is assumed to be mustSupport = false. In a profile (a constraint on an existing type), if mustSupport is not specific in either the differential or the snapshot, the mustSupport value is not changed from the base definition. Note, though, that the snapshot SHOULD always populate the mustSupport value
ElementDefinition.isModifier: Missing: An element is not a modifier element unless it is explicitly specified to be one
ElementDefinition.isSummary: Missing: An element is not included in the summary unless it is explicitly specified to be so

Mappings

ElementDefinition.path: RIM Mapping: N/A
ElementDefinition.path: v2 Mapping: N/A
ElementDefinition.path: 11179 Mapping: Name, Identifier & Context
ElementDefinition.representation: RIM Mapping: N/A
ElementDefinition.representation: v2 Mapping: N/A
ElementDefinition.representation: 11179 Mapping: n/a
ElementDefinition.sliceName: RIM Mapping: N/A
ElementDefinition.sliceName: v2 Mapping: N/A
ElementDefinition.sliceName: 11179 Mapping: n/a
ElementDefinition.sliceIsConstraining: RIM Mapping: N/A
ElementDefinition.sliceIsConstraining: v2 Mapping: N/A
ElementDefinition.sliceIsConstraining: 11179 Mapping: n/a
ElementDefinition.label: RIM Mapping: ./code/display
ElementDefinition.label: 11179 Mapping: n/a
ElementDefinition.code: RIM Mapping: ./code (root or translation)
ElementDefinition.code: v2 Mapping: OM1.7
ElementDefinition.code: 11179 Mapping: (Data_Element).data_element_concept.identifier
ElementDefinition.slicing: RIM Mapping: N/A
ElementDefinition.slicing: 11179 Mapping: n/a
ElementDefinition.short: RIM Mapping: N/A
ElementDefinition.short: 11179 Mapping: N/A
ElementDefinition.definition: RIM Mapping: ./text
ElementDefinition.definition: v2 Mapping: OM1.6, OM1.41
ElementDefinition.definition: 11179 Mapping: (Designatable_Item).definition.text acceptability=preferred in default context
ElementDefinition.comment: RIM Mapping: ./inboundRelationship[typeCode=SUBJ]/source[classCode=LIST, moodCode=EVN]/code
ElementDefinition.comment: v2 Mapping: NTE, OM1.32, OM1.33, OM1.39
ElementDefinition.comment: 11179 Mapping: (Administered_Item).explanatory_comment
ElementDefinition.requirements: RIM Mapping: ./inboundRelationship[typeCode=META]/source[classCode=ACT, moodCode=EVN, isCriterionInd=true]/reasonCode/originalText
ElementDefinition.requirements: 11179 Mapping: (Registered_item).document_reference[document_type=requirements].notation
ElementDefinition.alias: RIM Mapping: Not currently expressible
ElementDefinition.alias: v2 Mapping: OM1.8, OM1.52
ElementDefinition.alias: 11179 Mapping: (Designatable_Item).designation.sign acceptability!=preferred or context is other than default
ElementDefinition.min: RIM Mapping: N/A (MIF territory)
ElementDefinition.min: 11179 Mapping: Minimum size of data element values?
ElementDefinition.max: RIM Mapping: N/A (MIF territory)
ElementDefinition.max: v2 Mapping: OMC.10
ElementDefinition.max: 11179 Mapping: Maximum size of data element values?
ElementDefinition.base: RIM Mapping: N/A (MIF territory)
ElementDefinition.base: 11179 Mapping: n/a
ElementDefinition.contentReference: RIM Mapping: N/A
ElementDefinition.type: RIM Mapping: N/A (MIF territory)
ElementDefinition.type: v2 Mapping: OM1.3, OMC.9
ElementDefinition.type: 11179 Mapping: .domain.data+Q14type
ElementDefinition.type: IHE DEX Mapping: valueDomain.dataType
ElementDefinition.defaultValue[x]: RIM Mapping: N/A (MIF territory)
ElementDefinition.meaningWhenMissing: RIM Mapping: N/A (MIF territory)
ElementDefinition.orderMeaning: RIM Mapping: N/A (MIF territory)
ElementDefinition.fixed[x]: RIM Mapping: N/A (MIF territory)
ElementDefinition.fixed[x]: 11179 Mapping: N/A (only relevant when constraining, which 11179 doesn't do)
ElementDefinition.pattern[x]: RIM Mapping: N/A (MIF territory)
ElementDefinition.example: RIM Mapping: N/A (MIF territory)
ElementDefinition.minValue[x]: RIM Mapping: N/A (MIF territory)
ElementDefinition.maxValue[x]: RIM Mapping: N/A (MIF territory)
ElementDefinition.maxLength: RIM Mapping: N/A (MIF territory)
ElementDefinition.maxLength: v2 Mapping: OMC.12
ElementDefinition.maxLength: 11179 Mapping: .domain.maximum_character_quantity
ElementDefinition.condition: RIM Mapping: N/A (MIF territory)
ElementDefinition.constraint: RIM Mapping: N/A (MIF territory)
ElementDefinition.constraint: 11179 Mapping: ??
ElementDefinition.mustSupport: RIM Mapping: N/A (MIF territory)
ElementDefinition.mustSupport: 11179 Mapping: ??
ElementDefinition.isModifier: RIM Mapping: N/A (MIF territory)
ElementDefinition.isModifier: 11179 Mapping: ??
ElementDefinition.isModifierReason: RIM Mapping: N/A (MIF territory)
ElementDefinition.isSummary: RIM Mapping: N/A (MIF territory)
ElementDefinition.isSummary: 11179 Mapping: ??
ElementDefinition.binding: RIM Mapping: N/A (MIF territory)
ElementDefinition.binding: v2 Mapping: OM3, OMC.11
ElementDefinition.binding: 11179 Mapping: .domain
ElementDefinition.mapping: RIM Mapping: N/A (MIF territory)
ElementDefinition.mapping: 11179 Mapping: Registered_item).document_reference[document_type=mapping] Also, .meaning linkage to Data_Element_Concept is done as a mapping to a reference model. (Data_Element_Concepts are all defined in some sort of reference model, be that Object_Class and Property or some other mechanism)
ElementDefinition.mapping: IHE DEX Mapping: mappingSpecification