Resource type: valueset

Description

A ValueSet resource instance specifies a set of codes drawn from one or more code systems, intended for use in a particular context. Value sets link between [[[CodeSystem]]] definitions and their use in [coded elements](terminologies.html).

Elements

PathShortDefinitionComments
A set of codes drawn from one or more code systemsA ValueSet resource instance specifies a set of codes drawn from one or more code systems, intended for use in a particular context. Value sets link between [CodeSystem](codesystem.html) definitions and their use in [coded elements](terminologies.html).
urlCanonical identifier for this value set, represented as a URI (globally unique)An absolute URI that is used to identify this value set when it is referenced in a specification, model, design or an instance; also called its canonical identifier. This SHOULD be globally unique and SHOULD be a literal address at which at which an authoritative instance of this value set is (or will be) published. This URL can be the target of a canonical reference. It SHALL remain the same when the value set is stored on different servers.Can be a urn:uuid: or a urn:oid: but real http: addresses are preferred. Multiple instances may share the same URL if they have a distinct version. The determination of when to create a new version of a resource (same url, new version) vs. defining a new artifact is up to the author. Considerations for making this decision are found in [Technical and Business Versions](resource.html#versions). In some cases, the resource can no longer be found at the stated url, but the url itself cannot change. Implementations can use the [meta.source](resource.html#meta) element to indicate where the current master source of the resource can be found.
identifierAdditional identifier for the value set (business identifier)A formal identifier that is used to identify this value set when it is represented in other formats, or referenced in a specification, model, design or an instance.Typically, this is used for identifiers that can go in an HL7 V3 II (instance identifier) data type, and can then identify this value set outside of FHIR, where it is not possible to use the logical URI.
versionBusiness version of the value setThe identifier that is used to identify this version of the value set when it is referenced in a specification, model, design or instance. This is an arbitrary value managed by the value set author and is not expected to be globally unique. For example, it might be a timestamp (e.g. yyyymmdd) if a managed version is not available. There is also no expectation that versions can be placed in a lexicographical sequence.There may be different value set instances that have the same identifier but different versions. The version can be appended to the url in a reference to allow a reference to a particular business version of the value set with the format [url]|[version].
nameName for this value set (computer friendly)A natural language name identifying the value set. This name should be usable as an identifier for the module by machine processing applications such as code generation.The name is not expected to be globally unique. The name should be a simple alphanumeric type name to ensure that it is machine-processing friendly.A name should be provided unless the value set is a contained resource (e.g. an anonymous value set in a profile). Most registries will require a name.
titleName for this value set (human friendly)A short, descriptive, user-friendly title for the value set.This name does not need to be machine-processing friendly and may contain punctuation, white-space, etc.
statusdraft | active | retired | unknownThe status of this value set. Enables tracking the life-cycle of the content. The status of the value set applies to the value set definition (ValueSet.compose) and the associated ValueSet metadata. Expansions do not have a state.Allows filtering of value sets that are appropriate for use versus not.See also the [valueset-workflowStatus](extension-valueset-workflowstatus.html) extension for additional status information related to the editorial process.
experimentalFor testing purposes, not real usageA Boolean value to indicate that this value set is authored for testing purposes (or education/evaluation/marketing) and is not intended to be used for genuine usage.Allows filtering of value sets that are appropriate for use versus not.
dateDate last changedThe date (and optionally time) when the value set was created or revised (e.g. the 'content logical definition').Note that this is not the same as the resource last-modified-date, since the resource may be a secondary representation of the value set. Additional specific dates may be added as extensions or be found by consulting Provenances associated with past versions of the resource.
publisherName of the publisher (organization or individual)The name of the organization or individual that published the value set.Usually an organization but may be an individual. The publisher (or steward) of the value set is the organization or individual primarily responsible for the maintenance and upkeep of the value set. This is not necessarily the same individual or organization that developed and initially authored the content. The publisher is the primary point of contact for questions or issues with the value set. This item SHOULD be populated unless the information is available from context.
contactContact details for the publisherContact details to assist a user in finding and communicating with the publisher.May be a web site, an email address, a telephone number, etc.
descriptionNatural language description of the value setA free text natural language description of the value set from a consumer's perspective. The textual description specifies the span of meanings for concepts to be included within the Value Set Expansion, and also may specify the intended use and limitations of the Value Set.This description can be used to capture details such as why the value set was built, comments about misuse, instructions for clinical use and interpretation, literature references, examples from the paper world, etc. It is not a rendering of the value set as conveyed in the 'text' field of the resource itself. This item SHOULD be populated unless the information is available from context (e.g. the language of the value set is presumed to be the predominant language in the place the value set was created).The description is not intended to describe the semantics of the Value Set - there are no intrinsic semantics separate from the codes contained in its expansion. The description should capture its intended use, which is needed for ensuring integrity for its use in models across future changes. A description should be provided unless the value set is a contained resource (e.g. an anonymous value set in a profile). Most registries will require a description.
useContextThe context that the content is intended to supportThe content was developed with a focus and intent of supporting the contexts that are listed. These contexts may be general categories (gender, age, ...) or may be references to specific programs (insurance plans, studies, ...) and may be used to assist with indexing and searching for appropriate value set instances.When multiple useContexts are specified, there is no expectation that all or any of the contexts apply.
jurisdictionIntended jurisdiction for value set (if applicable)A legal or geographic region in which the value set is intended to be used.It may be possible for the value set to be used in jurisdictions other than those for which it was originally designed or intended.
immutableIndicates whether or not any change to the content logical definition may occurIf this is set to 'true', then no new versions of the content logical definition can be created. Note: Other metadata might still change.Normally immutability is set to 'false', which is the default assumption if it is not populated. Note that the implication is that if this is set to 'true', there may be only one ValueSet version for this definition. Immutability tends to be set to 'true' in one of two cases: - Where the value set, by the nature of its usage, cannot change. For example "All specializations of ACT in ActClassCode" - Where there's no safe way to express the "Purpose" such that someone else could safely make changes to the value set definition. Source workflow control must guarantee that the same URI always yields the same definition.
purposeWhy this value set is definedExplanation of why this value set is needed and why it has been designed as it has.This element does not describe the usage of the value set. Instead, it provides traceability of ''why'' the resource is either needed or ''why'' it is defined as it is. This may be used to point to source materials or specifications that drove the structure of this value set.
copyrightUse and/or publishing restrictionsA copyright statement relating to the value set and/or its contents. Copyright statements are generally legal restrictions on the use and publishing of the value set.nullFrequently, the copyright differs between the value set and the codes that are included. The copyright statement should clearly differentiate between these when required.
composeContent logical definition of the value set (CLD)A set of criteria that define the contents of the value set by including or excluding codes selected from the specified code system(s) that the value set draws from. This is also known as the Content Logical Definition (CLD).
compose.idUnique id for inter-element referencingUnique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
compose.extensionAdditional content defined by implementationsMay 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.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.
compose.modifierExtensionExtensions that cannot be ignored even if unrecognizedMay be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. 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. Applications processing a resource are required to check for modifier extensions. Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).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.
compose.lockedDateFixed date for references with no specified version (transitive)The Locked Date is the effective date that is used to determine the version of all referenced Code Systems and Value Set Definitions included in the compose that are not already tied to a specific version.With a defined lockedDate the value set is considered "Locked". Otherwise, the value set may have different expansions as underlying code systems and/or value sets evolve. The interpretation of lockedDate is often dependent on the context - e.g. a SNOMED CT derived value set with a lockedDate will have a different expansion in USA than in UK. If a value set specifies a version for include and exclude statements, and also specifies a locked date, the specified versions need to be available that date, or the value set will not be usable.
compose.inactiveWhether inactive codes are in the value setWhether inactive codes - codes that are not approved for current use - are in the value set. If inactive = true, inactive codes are to be included in the expansion, if inactive = false, the inactive codes will not be included in the expansion. If absent, the behavior is determined by the implementation, or by the applicable $expand parameters (but generally, inactive codes would be expected to be included).Note that in the FHIR terminology framework, "deprecated" does not mean inactive, but in some code systems (e.g. LOINC, deprecated means inactive). Code systems should define what codes are considered to be inactive. If this is not clearly defined (including in the FHIR code system resource), then all codes are assumed to be active. The Value Set Definition specification defines an ActiveOnly eleent, which is the reverse of this element e.g. (ValueSet.compose.inactive=FALSE) is the same as (VSD.ActiveOnly=TRUE).
compose.includeInclude one or more codes from a code system or other value set(s)Include one or more codes from a code system or other value set(s).All the conditions in an include must be true. If a system is listed, all the codes from the system are listed. If one or more filters are listed, all of the filters must apply. If one or more value sets are listed, the codes must be in all the value sets. E.g. each include is 'include all the codes that meet all these conditions'.
compose.include.idUnique id for inter-element referencingUnique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
compose.include.extensionAdditional content defined by implementationsMay 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.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.
compose.include.modifierExtensionExtensions that cannot be ignored even if unrecognizedMay be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. 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. Applications processing a resource are required to check for modifier extensions. Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).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.
compose.include.systemThe system the codes come fromAn absolute URI which is the code system from which the selected codes come from.If there are no codes or filters, the entire code system is included. Note that the set of codes that are included may contain abstract codes. See ''Coding.system'' for further documentation about the correct value for the system element.
compose.include.versionSpecific version of the code system referred toThe version of the code system that the codes are selected from, or the special version "*" for all versions.This is used when selecting the descendants of a concept - they may change between versions. If no version is specified, then the exact contents of the value set might not be known until a context of use binds it to a particular version. The special value "*" means all version; It is at server discrection regarding expansions and which versions must be supported.
compose.include.conceptA concept defined in the systemSpecifies a concept to be included or excluded.The list of concepts is considered ordered, though the order might not have any particular significance. Typically, the order of an expansion follows that defined in the compose element.
compose.include.concept.idUnique id for inter-element referencingUnique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
compose.include.concept.extensionAdditional content defined by implementationsMay 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.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.
compose.include.concept.modifierExtensionExtensions that cannot be ignored even if unrecognizedMay be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. 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. Applications processing a resource are required to check for modifier extensions. Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).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.
compose.include.concept.codeCode or expression from systemSpecifies a code for the concept to be included or excluded.Expressions are allowed if defined by the underlying code system.
compose.include.concept.displayText to display for this code for this value set in this valuesetThe text to display to the user for this concept in the context of this valueset. If no display is provided, then applications using the value set use the display specified for the code by the system.The value set resource allows for an alternative display to be specified for when this concept is used in this particular value set. See notes in the value set narrative about the correct use of this element.
compose.include.concept.designationAdditional representations for this conceptAdditional representations for this concept when used in this value set - other languages, aliases, specialized purposes, used for particular purposes, etc.Concepts have both a ```display``` and an array of ```designation```. The display is equivalent to a special designation with an implied ```designation.use``` of "primary code" and a language equal to the [Resource Language](resource.html#language).
compose.include.concept.designation.idUnique id for inter-element referencingUnique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
compose.include.concept.designation.extensionAdditional content defined by implementationsMay 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.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.
compose.include.concept.designation.modifierExtensionExtensions that cannot be ignored even if unrecognizedMay be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. 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. Applications processing a resource are required to check for modifier extensions. Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).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.
compose.include.concept.designation.languageHuman language of the designationThe language this designation is defined for.In the absence of a language, the resource language applies.
compose.include.concept.designation.useTypes of uses of designationsA code that represents types of uses of designations.If no use is provided, the designation can be assumed to be suitable for general display to a human user.
compose.include.concept.designation.valueThe text value for this designationThe text value for this designation.
compose.include.filterSelect codes/concepts by their properties (including relationships)Select concepts by specify a matching criterion based on the properties (including relationships) defined by the system, or on filters defined by the system. If multiple filters are specified, they SHALL all be true.Selecting codes by specifying filters based on properties is only possible where the underlying code system defines appropriate properties. Note that in some cases, the underlying code system defines the logical concepts but not the literal codes for the concepts. In such cases, the literal definitions may be provided by a third party.
compose.include.filter.idUnique id for inter-element referencingUnique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
compose.include.filter.extensionAdditional content defined by implementationsMay 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.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.
compose.include.filter.modifierExtensionExtensions that cannot be ignored even if unrecognizedMay be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. 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. Applications processing a resource are required to check for modifier extensions. Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).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.
compose.include.filter.propertyA property/filter defined by the code systemA code that identifies a property or a filter defined in the code system.
compose.include.filter.op= | is-a | descendent-of | is-not-a | regex | in | not-in | generalizes | existsThe kind of operation to perform as a part of the filter criteria.In case filter.property represents a property of the system, the operation applies to the selected property. In case filter.property represents a filter of the system, the operation SHALL match one of the CodeSystem.filter.operator values.
compose.include.filter.valueCode from the system, or regex criteria, or boolean value for existsThe match value may be either a code defined by the system, or a string value, which is a regex match on the literal string of the property value (if the filter represents a property defined in CodeSystem) or of the system filter value (if the filter represents a filter defined in CodeSystem) when the operation is 'regex', or one of the values (true and false), when the operation is 'exists'.Use regex matching with care - full regex matching on every SNOMED CT term is prohibitive, for example.
compose.include.valueSetSelect the contents included in this value setSelects the concepts found in this value set (based on its value set definition). This is an absolute URI that is a reference to ValueSet.url. If multiple value sets are specified this includes the union of the contents of all of the referenced value sets.The value set URI is either a logical reference to a defined value set such as a [SNOMED CT reference set](snomedct.html#implicit), or a direct reference to a value set definition using ValueSet.url. The reference might not refer to an actual FHIR ValueSet resource; in this case, whatever is referred to is an implicit definition of a value set that needs to be clear about how versions are resolved.
compose.excludeExplicitly exclude codes from a code system or other value setsExclude one or more codes from the value set based on code system filters and/or other value sets.Usually this is used to selectively exclude codes that were included by subsumption in the inclusions. Any display names specified for the codes are ignored.
expansionUsed when the value set is "expanded"A value set can also be "expanded", where the value set is turned into a simple collection of enumerated codes. This element holds the expansion, if it has been performed.Expansion is performed to produce a collection of codes that are ready to use for data entry or validation. Value set expansions are always considered to be stateless - they are a record of the set of codes in the value set at a point in time under a given set of conditions, and are no subject to ongoing maintenance. Expansion.parameter is a simplified list of parameters - a subset of the features of the [Parameters](parameters.html) resource.
expansion.idUnique id for inter-element referencingUnique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
expansion.extensionAdditional content defined by implementationsMay 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.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.
expansion.modifierExtensionExtensions that cannot be ignored even if unrecognizedMay be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. 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. Applications processing a resource are required to check for modifier extensions. Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).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.
expansion.identifierIdentifies the value set expansion (business identifier)An identifier that uniquely identifies this expansion of the valueset, based on a unique combination of the provided parameters, the system default parameters, and the underlying system code system versions etc. Systems may re-use the same identifier as long as those factors remain the same, and the expansion is the same, but are not required to do so. This is a business identifier.Typically, this uri is a UUID (e.g. urn:uuid:8230ff20-c97a-4167-a59d-dc2cb9df16dd).
expansion.timestampTime ValueSet expansion happenedThe time at which the expansion was produced by the expanding system.This SHOULD be a fully populated instant, but in some circumstances, value sets are expanded by hand, and the expansion is published without that precision.
expansion.totalTotal number of codes in the expansionThe total number of concepts in the expansion. If the number of concept nodes in this resource is less than the stated number, then the server can return more using the offset parameter.Paging only applies to flat expansions.
expansion.offsetOffset at which this resource startsIf paging is being used, the offset at which this resource starts. I.e. this resource is a partial view into the expansion. If paging is not being used, this element SHALL NOT be present.Paging only applies to flat expansions. If a filter is applied, the count is the number of concepts that matched the filter, not the number of concepts in an unfiltered view of the expansion.
expansion.parameterParameter that controlled the expansion processA parameter that controlled the expansion process. These parameters may be used by users of expanded value sets to check whether the expansion is suitable for a particular purpose, or to pick the correct expansion.The server decides which parameters to include here, but at a minimum, the list SHOULD include all of the parameters that affect the $expand operation. If the expansion will be persisted all of these parameters SHALL be included. If the codeSystem on the server has a specified version then this version SHALL be provided as a parameter in the expansion (note that not all code systems have a version).
expansion.parameter.idUnique id for inter-element referencingUnique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
expansion.parameter.extensionAdditional content defined by implementationsMay 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.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.
expansion.parameter.modifierExtensionExtensions that cannot be ignored even if unrecognizedMay be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. 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. Applications processing a resource are required to check for modifier extensions. Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).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.
expansion.parameter.nameName as assigned by the client or serverName of the input parameter to the $expand operation; may be a server-assigned name for additional default or other server-supplied parameters used to control the expansion process.The names are assigned at the discretion of the server.
expansion.parameter.value[x]Value of the named parameterThe value of the parameter.
expansion.containsCodes in the value setThe codes that are contained in the value set expansion.
expansion.contains.idUnique id for inter-element referencingUnique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
expansion.contains.extensionAdditional content defined by implementationsMay 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.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.
expansion.contains.modifierExtensionExtensions that cannot be ignored even if unrecognizedMay be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. 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. Applications processing a resource are required to check for modifier extensions. Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).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.
expansion.contains.systemSystem value for the codeAn absolute URI which is the code system in which the code for this item in the expansion is defined.
expansion.contains.abstractIf user cannot select this entryIf true, this entry is included in the expansion for navigational purposes, and the user cannot select the code directly as a proper value.This should not be understood to exclude its use for searching (e.g. by subsumption testing). The client should know whether it is appropriate for the user to select an abstract code or not.
expansion.contains.inactiveIf concept is inactive in the code systemIf the concept is inactive in the code system that defines it. Inactive codes are those that are no longer to be used, but are maintained by the code system for understanding legacy data. It might not be known or specified whether an concept is inactive (and it may depend on the context of use).This should only have a value if the concept is inactive.
expansion.contains.versionVersion in which this code/display is definedThe version of the code system from this code was taken. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured, and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.The exact value of the version string is specified by the system from which the code is derived.
expansion.contains.codeCode - if blank, this is not a selectable codeThe code for this item in the expansion hierarchy. If this code is missing the entry in the hierarchy is a place holder (abstract) and does not represent a valid code in the value set.
expansion.contains.displayUser display for the conceptThe recommended display for this item in the expansion.
expansion.contains.designationAdditional representations for this itemAdditional representations for this item - other languages, aliases, specialized purposes, used for particular purposes, etc. These are relevant when the conditions of the expansion do not fix to a single correct representation.The designations provided must be based on the value set and code system definitions.
expansion.contains.containsCodes contained under this entryOther codes and entries contained under this entry in the hierarchy.If the expansion uses this element, there is no implication about the logical relationship between them, and the structure cannot be used for logical inferencing. The structure exists to provide navigational assistance for helping human users to locate codes in the expansion.

Scope and Usage

The FHIR terminology specification is based on two key concepts, originally defined in HL7 v3 Core Principles:

Value sets have 2 aspects:

The ValueSet resource can carry either the .compose or the .expansion, both of them, or neither of them (if only the metadata is being represented). There is an "$expand" operation which can be used to ask a server to generate an expansion given the composition rules, in a particular context, and a "$validate-code" operation which can be used to ask a server to check whether a given code or concept is in the value set in a particular context.

Boundaries and Relationships

Value Sets are used by many resources:

For a full list of uses, see below.

The Characteristics of the ValueSet resource are derived from Formal Value Set Definitions:

Background and Context

When using value sets, proper differentiation between a code system and a value set is important. This is one very common area where significant clinical safety risks occur in practice. Implementers should be familiar with the content in Using Codes in Resources.

ValueSet Identification

A value set has 3 identifiers:

In addition, any expansion for the value set also has ValueSet.expansion.identifier which uniquely identifies each expansion. For further information regarding resource identification, see Resource Identity.

This means that each value set has 2 different URLs that can be used to reference it - its canonical URL (the url element), and its local location from which it may be retrieved (which includes the id element). Because it is common practice to copy (cache) value sets locally, most references to value sets use the canonical URL.

For example, the value sets published as part of FHIR all have a location ("literal") URI which is the URL where they may be accessed in the FHIR specification itself. Note, though, that while a new version of the FHIR Specification is being prepared, value sets that are published in the drafts will not be found in the current published FHIR specification at their canonical URL.

Alternatively, the identifier and version elements may be used to reference this value set in a design, a profile, a CDA template or HL7 v3 message (in the CD data type valueSet and valueSetVersion properties). These different contexts may make additional restrictions on the possible values of these elements. The identifier is generally not needed when using value sets in a FHIR context, where the canonical URL is always the focus.

Intensional vs Extensional

A value set may be described as intensional or extensional. The terms intensional and extensional come from the fields of mathematical logic and set theory.

An intensional value set is typically algorithmically defined. That is, the code group is defined as a rule e.g. all codes with the word diabetes in their description). The key benefit of intensional code groups is that they can be dynamically updated. Dynamic updating helps healthcare organizations keep current when new drugs (and their associated codes) become available or codes for diseases and other clinical concepts change. An intensional value set designed to contain all of the drugs in the beta blocker category can automatically receive a new beta blocker’s code as soon as it hits the market.

Extensional value sets, meanwhile, are enumerated lists of codes where each code is listed individually. This gives the author and user of the value set more control over the which codes are in the value set, but there is a greater maintenance burden to ensure that the value set is kept up to date.

Composition Rules

A value set can be a simple list of included codes, or it can be some kind of general selection criteria using the facilities provided by the code system. For these value sets:

Display and Designations

Concepts used in ValueSets can have a display, which is a short text that represents the meaning of the concept to human users in the context of the value set (which often has narrower meaning and therefore is amenable to shorter displays. If a display is not provided, the value set uses the display from the code system (which is the preferred approach, because overriding the display can lead to very unsafe outcomes).

When a value set enumerates codes, it is sometimes useful to define an alternative display for the code that is to be used wherever the value set is expanded and used in a UI. This facility is provided to cover the following circumstances:

Note that care must be taken in order to avoid "changing the meaning" of the concept by implying that it means something other than the explicit definition of the concept in the underlying code system (e.g., in the case above, using a display of "Glucose Concentration at 10pm"). For this reason, some contexts of use do not allow a display to be associated with a specific code in a value set.

Any display name for a concept provided in the value set is for display to a human user. The display in the Coding that results from a user selecting a concept from the expansion must be taken from the underlying code system definition, even if a value set is referenced explicitly in the Coding (e.g. by an extension). The correct display for a code can be determined by a $lookup operation. Any alternative display specified in the value set would go in CodeableConcept.text, perhaps appended to the UI label for the matching data element.

As an example, the LOINC code 55423-8 has a display value of "Number of steps in unspecified time Pedometer". A value set for a pick list in a patient generated data form might choose a simpler name:

{
  "resourceType" : "ValueSet",
  "compose" : {
    "include" : [{
      "system" : "http://loinc.org",
      "concept" : [{
        "code" : "55423-8",
        "display" : "Step Count"
      }]
    }]
  }
}

The expansion generated by a terminology server will have this:

{
  "resourceType" : "ValueSet",
  "expansion" : {
    "contains" : [{
      "system" : "http://loinc.org",
      "code" : "55423-8",
      "display" : "Step Count"
    }]
  }
}

The expansion display is taken from the value set, and this is what is displayed in the pick list. Once the user picks the code, it will appear in the Observation.code like this:

{
  "resourceType" : "Observation",
  "code" : {
    "coding" : [{
      "system" : "http://loinc.org",
      "code" : "55423-8",
      "display" : "Number of steps in unspecified time Pedometer"
    }],
    "text" : "Step Count"
  }
}

Note that the correct value for the display is not in the expansion above. The client can either omit the display, look it up using $lookup, or the server might pre-populate it in the expansion:

{
  "resourceType" : "ValueSet",
  "expansion" : {
    "contains" : [{
      "system" : "http://loinc.org",
      "code" : "55423-8",
      "display" : "Step Count",
      "designation" : [{
        "use" : {
          "system" : "http://snomed.info/sct",
          "code" : "900000000000003001"
        },
        "value" : "Number of steps in unspecified time Pedometer"
      }]
    }]
  }
}

Irrespective of this, the display in the expansion always goes in CodeableConcept.text.

In addition to the display, a concept can have one or more designation elements. The display is equivalent to a special designation with an implied designation.use of "primary code" and a language equal to the Resource Language. The designations can provide additional displays for other language, as well as designations for other purposes. When using concepts, applications use the display unless the language or usage in context provide a reason to use one of the designations.

Value Sets with multiple code systems

Value sets may select codes from multiple code systems - either by including codes from different systems, or importing other value sets that include them. A typical use for crossing code systems is when including a set of codes, and adding a few additional codes to cover cases not catered to by the included codes (e.g. Data missing or workflow error codes).

Best Practice Note: Mixing definitional systems offers the potential for confusing, overlapping, and inconsistent definitions. Creating value sets that cross code systems should be done with care to avoid creating definitional confusion.

Value sets should only include well differentiated concepts, but many value sets and code systems do not have well differentiated concepts because of various real world constraints.

Code systems Note

Each Code System defines which filters can be used in ValueSet.compose.include.filter. All code systems have base filters and any additional filters defined in (CodeSystem.filter).

This specification also defines filters for various published code systems:

Value Set Expansion

A value set can be "expanded", where the definition of the value set is used to create a simple collection of codes suitable for use for data entry or validation. There is a defined operation $expand to ask a server to perform this expansion. Expansions are most useful when a value set includes all the codes in a code system, or a set of codes by filter.

A resource that represents a value set expansion includes the same identification details as the definition of the value set, and MAY include the definition of the value set (.compose). In addition, it has an .expansion element which contains the list of codes that constitute the value set expansion. Each contained code can include nested contained codes - see below for further discussion.

When a request for an expansion is received (e.g., for the $expand operation), the following process should be followed:

The final "result set" is then represented in expansion. Note that the expansion structure is inherently ordered; this specification does not fix the meaning of use of the order. The conceptual approach described should not be understood to prohibit any implementation approach in these regards. In addition, note that the method described above is a conceptual approach; individual servers may choose to follow alternative approaches that are more efficient, as long as the outcome is the same.

[%dragons-start%]

The impact of Code System supplements on value set expansion - and therefore value set validation - is subject to ongoing experimentation and implementation testing, and further clarification and additional rules might be proposed in future versions of this specification.

[%dragons-end%]

Hierarchical Expansions

The expansion MAY be hierarchical - that is, it may have contains element that contain their own sub-elements, to any level of depth. This specification does not fix the meaning of the hierarchy: there is no implication about the logical relationship between the nested contain elements, and the structure cannot be used for logical inferencing. The structure exists to provide navigational assistance for helping human users to locate codes in the expansion. There is an example of use of a hierarchical expansion.

Note that the CodeSystem resource and ValueSet.compose offer no direct support for defining hierarchies and groups; applications may want to take advantage of the expand-rules and expand-group extensions as an implementation feature. An expansion may include entries in the expansion that only serve an arbitrary grouping purpose, to make it easier for a human to use the list. These entries have no system or code, and must be marked as abstract.

Uniqueness of Concepts in Expansions

Value set definitions may lead to more than one instruction to include a given concept in the value set across the includes and imports. No matter how many times the definitions include a concept, it is only present in the value set once, and will only appear once in a flat expansion of the value set. Note, however, that a concept may appear more than once in a nested hierarchy when the expansion is prepared for UI use (irrespective of how many times it is included in the definitions). Note that uniqueness is based on system/version/code; it is possible to include the same concept from different versions of a code system in the same expansion, though this is generally confusing for users and should be avoided.

The codes in the expansion should be treated as case sensitive - implementers should use the correct case. Implementers can consult the definition of the underlying code systems to determine whether the code system that defines the code is case sensitive or not.

Expansion Identifiers

It is important that expansions be identified properly. Any value set definition may produce an infinite number of expansions, depending on the operation parameters. Any expansions produced must be clearly identified so that there is no confusion. The following rules apply:

Expansion Parameters

The expansion contains a set of parameters in ValueSet.expansion.parameter that record what controlled the expansion process. These parameters may be used by users of expanded value sets to check whether the expansion is suitable for a particular purpose, or to pick the correct expansion. The server decides which parameters to include here, but at a minimum, the list SHOULD include all of the parameters that affect the $expand operation. If the expansion will be persisted all of these parameters SHALL be included. If the codeSystem on the server has a specified version then this version SHALL be provided as a parameter in the expansion (note that not all code systems have a version).

The following parameters are predefined by the $expand operation, and are suitable for use in the expansion parameters:

[%shortparameterlist ValueSet/$expand:filter,date,offset,count,includeDesignations,designation,includeDefinition,activeOnly,excludeNested,excludeNotForUI,excludePostCoordinated,displayLanguage,exclude-system,system-version,check-system-version,force-system-version%]

The count and offset parameters are important. If the expansion is a page out of the whole expansion, the offset and count parameters SHALL be populated. Clients can reliably use the count/offset parameters to determine whether the whole expansion is returned.

Other parameters that servers may be required to use:

[canonical]#CodeSystem.content[content] : The content value for the code system for the canonical URL. Applications generating expansions SHALL use this parameter if the CodeSystem.content value is "fragment" or "
[canonical1]#supplement[canonical2] : Indicates that the specified supplement (canonical2) contributed to the content of the expansion for the code system canonical1 (by influencing selection, or providing designations). Applications generating expansions SHALL use this parameter to record that a supplement was used durin the expansion process

Beyond this, servers MAY define their own parameters, though Terminology server authors are requested to bring additional parameters to HL7 (via 'Propose a change' link below) in the interests of interoperability.

Servers can also create and store Provenance statements about the expansion, or AuditEvent records of the expansion process if further transparency is required. These resources can contain considerable detail about the various inputs to the process, and any significant decisions by the expansion engine. Further details around this (and profiles on the relevant resources) may be provided in future versions of this specification or related implementation guides.

[%feedback-note%] The existing set of parameters are intended to cover the vast majority of use cases, but there are some cases where the parameters do not provide enough control to a client, particularly with regard to combinations of parameters, and the interplay between code system versions and other parameters. Implementers may need to define their own value sets to meet these requirements.

Ongoing feedback is welcome at [link to be provided] [%end-note%]

Storing Expansions

Whether to store expanded value sets, or simply to store their definitions and expand on the fly is a matter for system deployment. Some servers, including public value sets servers, only store expansions. However, any system that stores an expansion must be concerned with how to determine whether the expansion is still current, and this requires deep knowledge of how the expansion was created. A system with a dedicated terminology server that returns expansions on demand avoids this problem, but leaves open the question of how to audit the specific expansion that was used for a particular case. One solution to this is to use a dedicated terminology server, and have the clients ask for expansions on demand based on the value set definitions, and for the server to store (and reuse as appropriate) the returned expansion (when it reuses the expansion, ValueSet.expansion.identifier will be the same). If expansions are shared, users need to be aware of how expansion identifiers (which may be server specific) work.

Searching for codes in value sets

The search parameters defined on ValueSet include the code parameter. This is intended to allow a consumer to find all the value sets that include a particular code. However, fully evaluating this search parameter is extremely onerous for a server. Further, whether a code is in a value set depends on the context in which expansions are performed (see the $expand operation). For this reason, the degree to which the search parameter is supported can be declared in the Terminology Capability statement.

Combinations of .compose and .expansion

Use cases for the different combinations:

Search Parameters

codeThis special parameter searches for codes in the value set. See additional notes on the ValueSet resourceValueSet.expansion.contains.code | ValueSet.compose.include.concept.code
expansionIdentifies the value set expansion (business identifier)ValueSet.expansion.identifier
referenceA code system included or excluded in the value set or an imported value setValueSet.compose.include.system

Extension Definitions

These are extension definitions for this resource defined by the spec

Profiles based on this resource

Shareable ValueSet

Enforces the minimum information set for the value set metadata required by HL7 and other organizations that share and publish value sets

Elements

PathShortDefinitionComments
A set of codes drawn from one or more code systemsA ValueSet resource instance specifies a set of codes drawn from one or more code systems, intended for use in a particular context. Value sets link between [CodeSystem](codesystem.html) definitions and their use in [coded elements](terminologies.html).
urlCanonical identifier for this value set, represented as a URI (globally unique)An absolute URI that is used to identify this value set when it is referenced in a specification, model, design or an instance; also called its canonical identifier. This SHOULD be globally unique and SHOULD be a literal address at which at which an authoritative instance of this value set is (or will be) published. This URL can be the target of a canonical reference. It SHALL remain the same when the value set is stored on different servers.Can be a urn:uuid: or a urn:oid: but real http: addresses are preferred. Multiple instances may share the same URL if they have a distinct version. The determination of when to create a new version of a resource (same url, new version) vs. defining a new artifact is up to the author. Considerations for making this decision are found in [Technical and Business Versions](resource.html#versions). In some cases, the resource can no longer be found at the stated url, but the url itself cannot change. Implementations can use the [meta.source](resource.html#meta) element to indicate where the current master source of the resource can be found.
identifierAdditional identifier for the value set (business identifier)A formal identifier that is used to identify this value set when it is represented in other formats, or referenced in a specification, model, design or an instance.Typically, this is used for identifiers that can go in an HL7 V3 II (instance identifier) data type, and can then identify this value set outside of FHIR, where it is not possible to use the logical URI.
versionBusiness version of the value setThe identifier that is used to identify this version of the value set when it is referenced in a specification, model, design or instance. This is an arbitrary value managed by the value set author and is not expected to be globally unique. For example, it might be a timestamp (e.g. yyyymmdd) if a managed version is not available. There is also no expectation that versions can be placed in a lexicographical sequence.There may be different value set instances that have the same identifier but different versions. The version can be appended to the url in a reference to allow a reference to a particular business version of the value set with the format [url]|[version].
nameName for this value set (computer friendly)A natural language name identifying the value set. This name should be usable as an identifier for the module by machine processing applications such as code generation.The name is not expected to be globally unique. The name should be a simple alphanumeric type name to ensure that it is machine-processing friendly.A name should be provided unless the value set is a contained resource (e.g. an anonymous value set in a profile). Most registries will require a name.
titleName for this value set (human friendly)A short, descriptive, user-friendly title for the value set.This name does not need to be machine-processing friendly and may contain punctuation, white-space, etc.
statusdraft | active | retired | unknownThe status of this value set. Enables tracking the life-cycle of the content. The status of the value set applies to the value set definition (ValueSet.compose) and the associated ValueSet metadata. Expansions do not have a state.Allows filtering of value sets that are appropriate for use versus not.See also the [valueset-workflowStatus](extension-valueset-workflowstatus.html) extension for additional status information related to the editorial process.
experimentalFor testing purposes, not real usageA Boolean value to indicate that this value set is authored for testing purposes (or education/evaluation/marketing) and is not intended to be used for genuine usage.Allows filtering of value sets that are appropriate for use versus not.
dateDate last changedThe date (and optionally time) when the value set was created or revised (e.g. the 'content logical definition').Note that this is not the same as the resource last-modified-date, since the resource may be a secondary representation of the value set. Additional specific dates may be added as extensions or be found by consulting Provenances associated with past versions of the resource.
publisherName of the publisher (organization or individual)The name of the organization or individual that published the value set.Usually an organization but may be an individual. The publisher (or steward) of the value set is the organization or individual primarily responsible for the maintenance and upkeep of the value set. This is not necessarily the same individual or organization that developed and initially authored the content. The publisher is the primary point of contact for questions or issues with the value set. This item SHOULD be populated unless the information is available from context.
contactContact details for the publisherContact details to assist a user in finding and communicating with the publisher.May be a web site, an email address, a telephone number, etc.
descriptionNatural language description of the value setA free text natural language description of the value set from a consumer's perspective. The textual description specifies the span of meanings for concepts to be included within the Value Set Expansion, and also may specify the intended use and limitations of the Value Set.This description can be used to capture details such as why the value set was built, comments about misuse, instructions for clinical use and interpretation, literature references, examples from the paper world, etc. It is not a rendering of the value set as conveyed in the 'text' field of the resource itself. This item SHOULD be populated unless the information is available from context (e.g. the language of the value set is presumed to be the predominant language in the place the value set was created).The description is not intended to describe the semantics of the Value Set - there are no intrinsic semantics separate from the codes contained in its expansion. The description should capture its intended use, which is needed for ensuring integrity for its use in models across future changes. A description should be provided unless the value set is a contained resource (e.g. an anonymous value set in a profile). Most registries will require a description.
useContextThe context that the content is intended to supportThe content was developed with a focus and intent of supporting the contexts that are listed. These contexts may be general categories (gender, age, ...) or may be references to specific programs (insurance plans, studies, ...) and may be used to assist with indexing and searching for appropriate value set instances.When multiple useContexts are specified, there is no expectation that all or any of the contexts apply.
jurisdictionIntended jurisdiction for value set (if applicable)A legal or geographic region in which the value set is intended to be used.It may be possible for the value set to be used in jurisdictions other than those for which it was originally designed or intended.
immutableIndicates whether or not any change to the content logical definition may occurIf this is set to 'true', then no new versions of the content logical definition can be created. Note: Other metadata might still change.Normally immutability is set to 'false', which is the default assumption if it is not populated. Note that the implication is that if this is set to 'true', there may be only one ValueSet version for this definition. Immutability tends to be set to 'true' in one of two cases: - Where the value set, by the nature of its usage, cannot change. For example "All specializations of ACT in ActClassCode" - Where there's no safe way to express the "Purpose" such that someone else could safely make changes to the value set definition. Source workflow control must guarantee that the same URI always yields the same definition.
purposeWhy this value set is definedExplanation of why this value set is needed and why it has been designed as it has.This element does not describe the usage of the value set. Instead, it provides traceability of ''why'' the resource is either needed or ''why'' it is defined as it is. This may be used to point to source materials or specifications that drove the structure of this value set.
copyrightUse and/or publishing restrictionsA copyright statement relating to the value set and/or its contents. Copyright statements are generally legal restrictions on the use and publishing of the value set.nullFrequently, the copyright differs between the value set and the codes that are included. The copyright statement should clearly differentiate between these when required.
composeContent logical definition of the value set (CLD)A set of criteria that define the contents of the value set by including or excluding codes selected from the specified code system(s) that the value set draws from. This is also known as the Content Logical Definition (CLD).
compose.idUnique id for inter-element referencingUnique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
compose.extensionAdditional content defined by implementationsMay 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.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.
compose.modifierExtensionExtensions that cannot be ignored even if unrecognizedMay be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. 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. Applications processing a resource are required to check for modifier extensions. Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).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.
compose.lockedDateFixed date for references with no specified version (transitive)The Locked Date is the effective date that is used to determine the version of all referenced Code Systems and Value Set Definitions included in the compose that are not already tied to a specific version.With a defined lockedDate the value set is considered "Locked". Otherwise, the value set may have different expansions as underlying code systems and/or value sets evolve. The interpretation of lockedDate is often dependent on the context - e.g. a SNOMED CT derived value set with a lockedDate will have a different expansion in USA than in UK. If a value set specifies a version for include and exclude statements, and also specifies a locked date, the specified versions need to be available that date, or the value set will not be usable.
compose.inactiveWhether inactive codes are in the value setWhether inactive codes - codes that are not approved for current use - are in the value set. If inactive = true, inactive codes are to be included in the expansion, if inactive = false, the inactive codes will not be included in the expansion. If absent, the behavior is determined by the implementation, or by the applicable $expand parameters (but generally, inactive codes would be expected to be included).Note that in the FHIR terminology framework, "deprecated" does not mean inactive, but in some code systems (e.g. LOINC, deprecated means inactive). Code systems should define what codes are considered to be inactive. If this is not clearly defined (including in the FHIR code system resource), then all codes are assumed to be active. The Value Set Definition specification defines an ActiveOnly eleent, which is the reverse of this element e.g. (ValueSet.compose.inactive=FALSE) is the same as (VSD.ActiveOnly=TRUE).
compose.includeInclude one or more codes from a code system or other value set(s)Include one or more codes from a code system or other value set(s).All the conditions in an include must be true. If a system is listed, all the codes from the system are listed. If one or more filters are listed, all of the filters must apply. If one or more value sets are listed, the codes must be in all the value sets. E.g. each include is 'include all the codes that meet all these conditions'.
compose.include.idUnique id for inter-element referencingUnique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
compose.include.extensionAdditional content defined by implementationsMay 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.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.
compose.include.modifierExtensionExtensions that cannot be ignored even if unrecognizedMay be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. 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. Applications processing a resource are required to check for modifier extensions. Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).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.
compose.include.systemThe system the codes come fromAn absolute URI which is the code system from which the selected codes come from.If there are no codes or filters, the entire code system is included. Note that the set of codes that are included may contain abstract codes. See ''Coding.system'' for further documentation about the correct value for the system element.
compose.include.versionSpecific version of the code system referred toThe version of the code system that the codes are selected from, or the special version "*" for all versions.This is used when selecting the descendants of a concept - they may change between versions. If no version is specified, then the exact contents of the value set might not be known until a context of use binds it to a particular version. The special value "*" means all version; It is at server discrection regarding expansions and which versions must be supported.
compose.include.conceptA concept defined in the systemSpecifies a concept to be included or excluded.The list of concepts is considered ordered, though the order might not have any particular significance. Typically, the order of an expansion follows that defined in the compose element.
compose.include.concept.idUnique id for inter-element referencingUnique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
compose.include.concept.extensionAdditional content defined by implementationsMay 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.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.
compose.include.concept.modifierExtensionExtensions that cannot be ignored even if unrecognizedMay be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. 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. Applications processing a resource are required to check for modifier extensions. Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).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.
compose.include.concept.codeCode or expression from systemSpecifies a code for the concept to be included or excluded.Expressions are allowed if defined by the underlying code system.
compose.include.concept.displayText to display for this code for this value set in this valuesetThe text to display to the user for this concept in the context of this valueset. If no display is provided, then applications using the value set use the display specified for the code by the system.The value set resource allows for an alternative display to be specified for when this concept is used in this particular value set. See notes in the value set narrative about the correct use of this element.
compose.include.concept.designationAdditional representations for this conceptAdditional representations for this concept when used in this value set - other languages, aliases, specialized purposes, used for particular purposes, etc.Concepts have both a ```display``` and an array of ```designation```. The display is equivalent to a special designation with an implied ```designation.use``` of "primary code" and a language equal to the [Resource Language](resource.html#language).
compose.include.concept.designation.idUnique id for inter-element referencingUnique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
compose.include.concept.designation.extensionAdditional content defined by implementationsMay 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.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.
compose.include.concept.designation.modifierExtensionExtensions that cannot be ignored even if unrecognizedMay be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. 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. Applications processing a resource are required to check for modifier extensions. Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).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.
compose.include.concept.designation.languageHuman language of the designationThe language this designation is defined for.In the absence of a language, the resource language applies.
compose.include.concept.designation.useTypes of uses of designationsA code that represents types of uses of designations.If no use is provided, the designation can be assumed to be suitable for general display to a human user.
compose.include.concept.designation.valueThe text value for this designationThe text value for this designation.
compose.include.filterSelect codes/concepts by their properties (including relationships)Select concepts by specify a matching criterion based on the properties (including relationships) defined by the system, or on filters defined by the system. If multiple filters are specified, they SHALL all be true.Selecting codes by specifying filters based on properties is only possible where the underlying code system defines appropriate properties. Note that in some cases, the underlying code system defines the logical concepts but not the literal codes for the concepts. In such cases, the literal definitions may be provided by a third party.
compose.include.filter.idUnique id for inter-element referencingUnique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
compose.include.filter.extensionAdditional content defined by implementationsMay 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.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.
compose.include.filter.modifierExtensionExtensions that cannot be ignored even if unrecognizedMay be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. 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. Applications processing a resource are required to check for modifier extensions. Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).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.
compose.include.filter.propertyA property/filter defined by the code systemA code that identifies a property or a filter defined in the code system.
compose.include.filter.op= | is-a | descendent-of | is-not-a | regex | in | not-in | generalizes | existsThe kind of operation to perform as a part of the filter criteria.In case filter.property represents a property of the system, the operation applies to the selected property. In case filter.property represents a filter of the system, the operation SHALL match one of the CodeSystem.filter.operator values.
compose.include.filter.valueCode from the system, or regex criteria, or boolean value for existsThe match value may be either a code defined by the system, or a string value, which is a regex match on the literal string of the property value (if the filter represents a property defined in CodeSystem) or of the system filter value (if the filter represents a filter defined in CodeSystem) when the operation is 'regex', or one of the values (true and false), when the operation is 'exists'.Use regex matching with care - full regex matching on every SNOMED CT term is prohibitive, for example.
compose.include.valueSetSelect the contents included in this value setSelects the concepts found in this value set (based on its value set definition). This is an absolute URI that is a reference to ValueSet.url. If multiple value sets are specified this includes the union of the contents of all of the referenced value sets.The value set URI is either a logical reference to a defined value set such as a [SNOMED CT reference set](snomedct.html#implicit), or a direct reference to a value set definition using ValueSet.url. The reference might not refer to an actual FHIR ValueSet resource; in this case, whatever is referred to is an implicit definition of a value set that needs to be clear about how versions are resolved.
compose.excludeExplicitly exclude codes from a code system or other value setsExclude one or more codes from the value set based on code system filters and/or other value sets.Usually this is used to selectively exclude codes that were included by subsumption in the inclusions. Any display names specified for the codes are ignored.
expansionUsed when the value set is "expanded"A value set can also be "expanded", where the value set is turned into a simple collection of enumerated codes. This element holds the expansion, if it has been performed.Expansion is performed to produce a collection of codes that are ready to use for data entry or validation. Value set expansions are always considered to be stateless - they are a record of the set of codes in the value set at a point in time under a given set of conditions, and are no subject to ongoing maintenance. Expansion.parameter is a simplified list of parameters - a subset of the features of the [Parameters](parameters.html) resource.
expansion.idUnique id for inter-element referencingUnique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
expansion.extensionAdditional content defined by implementationsMay 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.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.
expansion.modifierExtensionExtensions that cannot be ignored even if unrecognizedMay be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. 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. Applications processing a resource are required to check for modifier extensions. Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).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.
expansion.identifierIdentifies the value set expansion (business identifier)An identifier that uniquely identifies this expansion of the valueset, based on a unique combination of the provided parameters, the system default parameters, and the underlying system code system versions etc. Systems may re-use the same identifier as long as those factors remain the same, and the expansion is the same, but are not required to do so. This is a business identifier.Typically, this uri is a UUID (e.g. urn:uuid:8230ff20-c97a-4167-a59d-dc2cb9df16dd).
expansion.timestampTime ValueSet expansion happenedThe time at which the expansion was produced by the expanding system.This SHOULD be a fully populated instant, but in some circumstances, value sets are expanded by hand, and the expansion is published without that precision.
expansion.totalTotal number of codes in the expansionThe total number of concepts in the expansion. If the number of concept nodes in this resource is less than the stated number, then the server can return more using the offset parameter.Paging only applies to flat expansions.
expansion.offsetOffset at which this resource startsIf paging is being used, the offset at which this resource starts. I.e. this resource is a partial view into the expansion. If paging is not being used, this element SHALL NOT be present.Paging only applies to flat expansions. If a filter is applied, the count is the number of concepts that matched the filter, not the number of concepts in an unfiltered view of the expansion.
expansion.parameterParameter that controlled the expansion processA parameter that controlled the expansion process. These parameters may be used by users of expanded value sets to check whether the expansion is suitable for a particular purpose, or to pick the correct expansion.The server decides which parameters to include here, but at a minimum, the list SHOULD include all of the parameters that affect the $expand operation. If the expansion will be persisted all of these parameters SHALL be included. If the codeSystem on the server has a specified version then this version SHALL be provided as a parameter in the expansion (note that not all code systems have a version).
expansion.parameter.idUnique id for inter-element referencingUnique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
expansion.parameter.extensionAdditional content defined by implementationsMay 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.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.
expansion.parameter.modifierExtensionExtensions that cannot be ignored even if unrecognizedMay be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. 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. Applications processing a resource are required to check for modifier extensions. Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).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.
expansion.parameter.nameName as assigned by the client or serverName of the input parameter to the $expand operation; may be a server-assigned name for additional default or other server-supplied parameters used to control the expansion process.The names are assigned at the discretion of the server.
expansion.parameter.value[x]Value of the named parameterThe value of the parameter.
expansion.containsCodes in the value setThe codes that are contained in the value set expansion.
expansion.contains.idUnique id for inter-element referencingUnique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
expansion.contains.extensionAdditional content defined by implementationsMay 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.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.
expansion.contains.modifierExtensionExtensions that cannot be ignored even if unrecognizedMay be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. 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. Applications processing a resource are required to check for modifier extensions. Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).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.
expansion.contains.systemSystem value for the codeAn absolute URI which is the code system in which the code for this item in the expansion is defined.
expansion.contains.abstractIf user cannot select this entryIf true, this entry is included in the expansion for navigational purposes, and the user cannot select the code directly as a proper value.This should not be understood to exclude its use for searching (e.g. by subsumption testing). The client should know whether it is appropriate for the user to select an abstract code or not.
expansion.contains.inactiveIf concept is inactive in the code systemIf the concept is inactive in the code system that defines it. Inactive codes are those that are no longer to be used, but are maintained by the code system for understanding legacy data. It might not be known or specified whether an concept is inactive (and it may depend on the context of use).This should only have a value if the concept is inactive.
expansion.contains.versionVersion in which this code/display is definedThe version of the code system from this code was taken. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured, and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.The exact value of the version string is specified by the system from which the code is derived.
expansion.contains.codeCode - if blank, this is not a selectable codeThe code for this item in the expansion hierarchy. If this code is missing the entry in the hierarchy is a place holder (abstract) and does not represent a valid code in the value set.
expansion.contains.displayUser display for the conceptThe recommended display for this item in the expansion.
expansion.contains.designationAdditional representations for this itemAdditional representations for this item - other languages, aliases, specialized purposes, used for particular purposes, etc. These are relevant when the conditions of the expansion do not fix to a single correct representation.The designations provided must be based on the value set and code system definitions.
expansion.contains.containsCodes contained under this entryOther codes and entries contained under this entry in the hierarchy.If the expansion uses this element, there is no implication about the logical relationship between them, and the structure cannot be used for logical inferencing. The structure exists to provide navigational assistance for helping human users to locate codes in the expansion.