type: resource-definitionsresource: SearchParameter

SearchParameter Definitions

SearchParameter

Search parameter for a resource

Definition: A search parameter that defines a named search item that can be used to search/filter on a resource.

Comments: In FHIR, search is not performed directly on a resource (by XML or JSON path), but on a named parameter that maps into the resource content.

Cardinality: 0..*

Constraints: cnl-0 | warning | Name should be usable as an identifier for the module by machine processing applications such as code generation | name.exists() implies name.matches('^A-Z{1,254}$'); spd-1 | error | If an expression is present, there SHALL be a processingMode | expression.empty() or processingMode.exists(); spd-2 | error | Search parameters can only have chain names when the search parameter type is 'reference' | chain.empty() or type = 'reference'; spd-3 | error | Search parameters comparator can only be used on type 'number', 'date', 'quantity' or 'special'. | comparator.empty() or (type in ('number' | 'date' | 'quantity' | 'special')); spd-4 | error | Search parameter codes SHALL NOT contain '.', '$', '|', or whitespace characters | code.matches('^[^.\$\|\s]+$'); spd-5 | error | Search parameter aliases SHALL NOT contain '.', '$', '|', or whitespace characters | aliasCode.empty() or aliasCode.all(matches('^[^.\$\|\s]+$')).allTrue()

Mappings: v2=n/a; rim=n/a; w5=conformance.behavior

SearchParameter.url

Canonical identifier for this search parameter, represented as a URI (globally unique)

Definition: An absolute URI that is used to identify this search parameter 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 an authoritative instance of this search parameter is (or will be) published. This URL can be the target of a canonical reference. It SHALL remain the same when the search parameter is stored on different servers.

Comments: 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.

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 element to indicate where the current master source of the resource can be found.

Requirements: Allows the search parameter to be referenced by a single globally unique identifier. To allow referencing and reusing search parameter definitions under other names on operational systems (in case of name clash).

Cardinality: 1..1

Type: uri

Summary: true

Mappings: w5=FiveWs.identifier

SearchParameter.identifier

Additional identifier for the search parameter (business identifier)

Definition: A formal identifier that is used to identify this search parameter when it is represented in other formats, or referenced in a specification, model, design or an instance.

Requirements: Allows externally provided and/or usable business identifiers to be easily associated with the module.

Cardinality: 0..*

Type: Identifier

Summary: true

Mappings: w5=FiveWs.identifier

SearchParameter.version

Business version of the search parameter

Definition: The identifier that is used to identify this version of the search parameter when it is referenced in a specification, model, design or instance. This is an arbitrary value managed by the search parameter 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.

Comments: There may be different search parameter 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 search parameter with the format [url]|[version]. The version SHOULD NOT contain a '#' - see Business Version.

Cardinality: 0..1

Type: string

Summary: true

Mappings: w5=FiveWs.version

SearchParameter.versionAlgorithm[x]

How to compare versions

Definition: Indicates the mechanism used to compare versions to determine which is more current.

Comments: If set as a string, this is a FHIRPath expression that has two additional context variables passed in - %version1 and %version2 and will return a negative number if version1 is newer, a positive number if version2 and a 0 if the version ordering can't be successfully be determined.

Cardinality: 0..1

Type: string, Coding

Binding: extensible:version-algorithm

Summary: true

SearchParameter.name

Name for this search parameter (computer friendly)

Definition: A natural language name identifying the search parameter. This name should be usable as an identifier for the module by machine processing applications such as code generation.

Comments: 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.

Requirements: Support human navigation and code generation.

Conditions: cnl-0

Cardinality: 1..1

Type: string

Summary: true

SearchParameter.title

Name for this search parameter (human friendly)

Definition: A short, descriptive, user-friendly title for the search parameter.

Comments: This name does not need to be machine-processing friendly and may contain punctuation, white-space, etc.

Cardinality: 0..1

Type: string

Summary: true

SearchParameter.derivedFrom

Original definition for the search parameter

Definition: Where this search parameter is originally defined. If a derivedFrom is provided, then the details in the search parameter must be consistent with the definition from which it is defined. i.e. the parameter should have the same meaning, and (usually) the functionality should be a proper subset of the underlying search parameter.

Comments: The intent of this is that a server can designate that it provides support for a search parameter defined in the specification itself (e.g. value-quantity, but detail how it is supported by the server. This canonical reference SHOULD always be version-specific, as different versions of the base resource may have changes that would cause the derived search parameter to not be a valid derivation.

Cardinality: 0..1

Type: canonical

SearchParameter.status

draft | active | retired | unknown

Definition: The status of this search parameter. Enables tracking the life-cycle of the content.

Comments: Allows filtering of search parameters that are appropriate for use versus not.

See guidance around (not) making local changes to elements here.

Cardinality: 1..1

Type: code

Binding: required:publication-status

Summary: true

Is Modifier: true (Reason: This is labeled as "Is Modifier" because applications should not use a retired {{title}} without due consideration)

Mappings: w5=FiveWs.status

SearchParameter.experimental

For testing only - never for real usage

Definition: A Boolean value to indicate that this search parameter is authored for testing purposes (or education/evaluation/marketing) and no version of this resource will ever be intended for genuine usage.

Comments: Allows filtering of search parameters that are appropriate for use versus not.. Experimental resources might include example instances in implementation guides, instances created solely for testing purposes, etc

Requirements: Enables experimental content to be developed following the same lifecycle that would be used for a production-level search parameter.

Meaning if Missing: If absent, this resource is treated as though it is not experimental.

Cardinality: 0..1

Type: boolean

Summary: true

Mappings: w5=FiveWs.class

SearchParameter.date

Date last changed

Definition: The date (and optionally time) when the search parameter was last significantly changed. The date must change when the business version changes and it must change if the status code changes. In addition, it should change when the substantive content of the search parameter changes.

Comments: The date is often not tracked until the resource is published, but may be present on draft content. Note that this is not the same as the resource last-modified-date, since the resource may be a secondary representation of the search parameter. Additional specific dates may be added as extensions or be found by consulting Provenances associated with past versions of the resource.

See guidance around (not) making local changes to elements here.

Aliases: Revision Date

Cardinality: 0..1

Type: dateTime

Summary: true

Mappings: w5=FiveWs.recorded

SearchParameter.publisher

Name of the publisher/steward (organization or individual)

Definition: The name of the organization or individual responsible for the release and ongoing maintenance of the search parameter.

Comments: Usually an organization but may be an individual. The publisher (or steward) of the search parameter is the organization or individual primarily responsible for the maintenance and upkeep of the search parameter. 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 search parameter. This item SHOULD be populated unless the information is available from context.

Requirements: Helps establish the "authority/credibility" of the search parameter. May also allow for contact.

Cardinality: 0..1

Type: string

Summary: true

Mappings: w5=FiveWs.witness

SearchParameter.contact

Contact details for the publisher

Definition: Contact details to assist a user in finding and communicating with the publisher.

Comments: May be a web site, an email address, a telephone number, etc.

See guidance around (not) making local changes to elements here.

Cardinality: 0..*

Type: ContactDetail

Summary: true

SearchParameter.description

Natural language description of the search parameter

Definition: And how it used.

Comments: This description can be used to capture details such as comments about misuse, instructions for clinical use and interpretation, literature references, examples from the paper world, etc. It is not a rendering of the search parameter 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 search parameter is presumed to be the predominant language in the place the search parameter was created).

Cardinality: 1..1

Type: markdown

Summary: true

SearchParameter.useContext

The context that the content is intended to support

Definition: The 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 search parameter instances.

Comments: When multiple useContexts are specified, there is no expectation that all or any of the contexts apply.

Requirements: Assist in searching for appropriate content.

Cardinality: 0..*

Type: UsageContext

Summary: true

SearchParameter.jurisdiction

Jurisdiction of the authority that maintains the search parameter (if applicable)

Definition: A legal or geographic region in which the authority that maintains the resource is operating. In general, the jurisdiction is also found in the useContext. The useContext may reference additional jurisdictions because the defining jurisdiction does not necessarily limit the jurisdictions of use.

Comments: It may be possible for the search parameter to be used in jurisdictions other than those for which it was originally designed or intended.

DEPRECATION NOTE: For consistency, implementations are encouraged to migrate to using the new 'jurisdiction' code in the useContext element. (I.e. useContext.code indicating http://terminology.hl7.org/CodeSystem/usage-context-type#jurisdiction and useContext.valueCodeableConcept indicating the jurisdiction.)

Cardinality: 0..*

Type: CodeableConcept

Binding: extensible:jurisdiction

Summary: true

SearchParameter.purpose

Why this search parameter is defined

Definition: Explanation of why this search parameter is needed and why it has been designed as it has.

Comments: This element does not describe the usage of the search parameter. 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 search parameter.

Cardinality: 0..1

Type: markdown

Mappings: w5=FiveWs.why[x]; objimpl=no-gen-base

SearchParameter.copyright

Notice about intellectual property ownership, can include restrictions on use

Definition: A copyright statement relating to the search parameter and/or its contents. Copyright statements are notices of intellectual property ownership and can include restrictions on the use and publishing of the search parameter.

Comments: ...

Requirements: Consumers must be able to determine any legal restrictions on the use of the search parameter and/or its content.

Aliases: License, Restrictions

Cardinality: 0..1

Type: markdown

Mappings: objimpl=no-gen-base

SearchParameter.copyrightLabel

Definition: A short string (<50 characters), suitable for inclusion in a page footer that identifies the copyright holder, effective period, and optionally whether rights are restricted. (e.g. 'All rights reserved', 'Some rights reserved').

Comments: The copyright symbol and the '(c)' textual representation SHOULD NOT be included in this string. It will be added by software when rendering the notation. Full details about licensing, restrictions, warrantees, etc. goes in the more general 'copyright' element.

Requirements: Defines the content expected to be rendered in all representations of the artifact.

Cardinality: 0..1

Type: string

SearchParameter.code

Recommended name for parameter in search url

Definition: The label that is recommended to be used in the URL or the parameter name in a parameters resource for this search parameter. In some cases, servers may need to use a different CapabilityStatement searchParam.name to differentiate between multiple SearchParameters that happen to have the same code.

Comments: For maximum compatibility, use only lowercase ASCII characters and hyphens. The characters '.', '$', '|' and whitespace are prohibited as they are used as separators in search parameter processing. Note that HL7 will never define multiple search parameters with the same code.

Conditions: spd-4

Cardinality: 1..1

Type: code

Summary: true

SearchParameter.aliasCode

Additional recommended names for parameter in search url

Definition: Additional label that are recommended to be used in the URL or the parameter name in a parameters resource for this search parameter. Typically used to provide backwards-compatibility for renamed search parameters and translations into localized languages.

Comments: For maximum compatibility, use only lowercase ASCII characters and hyphens.

Conditions: spd-5

Cardinality: 0..*

Type: code

Summary: true

SearchParameter.base

The resource type(s) this search parameter applies to

Definition: The base resource type(s) that this search parameter can be used against.

Comments: A search parameter must always apply to at least one resource type. When search parameters apply to more than one resource type, they can be used against any of the listed resource types, or in a cross-type search (see Cross Resource Search).

Cardinality: 1..*

Type: code

Binding: required:version-independent-all-resource-types

Summary: true

SearchParameter.type

Definition: The type of value that a search parameter may contain, and how the content is interpreted.

Conditions: spd-2, spd-3

Cardinality: 1..1

Type: code

Binding: required:search-param-type

Summary: true

SearchParameter.expression

FHIRPath expression that extracts the values

Definition: A FHIRPath expression that returns a set of elements for the search parameter.

Comments: Note that the elements returned by the expression are sometimes complex elements where logic is required to determine quite how to handle them; e.g. CodeableConcepts may contain text and/or multiple codings, where the codings themselves contain a code and a system. For composite search parameters, the outcome of the expression must a collection of base elements from which the composites are derived.

Conditions: spd-1

Cardinality: 0..1

Type: string

SearchParameter.processingMode

normal | phonetic | other

Definition: How the search parameter relates to the set of elements returned by evaluating the expression query.

Conditions: spd-1

Cardinality: 0..1

Type: code

Binding: required:search-processingmode

SearchParameter.constraint

FHIRPath expression that constraints the usage of this SearchParameter

Definition: FHIRPath expression that defines/sets a complex constraint for when this SearchParameter is applicable.

Cardinality: 0..1

Type: string

SearchParameter.target

Types of resource (if a resource reference)

Definition: Types of resource (if a resource is referenced).

Comments: In some cases, targets may exist for a search parameter that do not exist for the specified FHIRPath for all of the resources identified in SearchParameter.base. For example, the core clinical-encounter search parameter allows both Encounter and EpisodeOfCare as targets, even though not all of the base resources have EpisodeOfCare as a valid target.

However, the list of targets SHOULD cover all targets that might appear that are permitted by the specified FHIRPath.

Cardinality: 0..*

Type: code

Binding: required:version-independent-all-resource-types

SearchParameter.multipleOr

Allow multiple values per parameter (or)

Definition: Whether multiple values are allowed for each time the parameter exists. Values are separated by commas, and the parameter matches if any of the values match.

Meaning if Missing: If not declared, then it is up to server discretion whether multiple 'or' repetitions are allowed

Cardinality: 0..1

Type: boolean

SearchParameter.multipleAnd

Allow multiple parameters (and)

Definition: Whether multiple parameters are allowed - e.g. more than one parameter with the same name. The search matches if all the parameters match.

Meaning if Missing: If not declared, then it is up to server discretion whether multiple 'and' repetitions are allowed

Cardinality: 0..1

Type: boolean

SearchParameter.comparator

eq | ne | gt | lt | ge | le | sa | eb | ap

Definition: Comparators supported for the search parameter.

Comments: If no comparators are listed, clients should not expect servers to support any comparators.

Conditions: spd-3

Cardinality: 0..*

Type: code

Binding: required:search-comparator

SearchParameter.modifier

Definition: A modifier supported for the search parameter.

Cardinality: 0..*

Type: code

Binding: required:search-modifier-all-codes

SearchParameter.chain

Chained names supported

Definition: Contains the names of any search parameters which may be chained to the containing search parameter. Chained parameters may be added to search parameters of type reference and specify that resources will only be returned if they contain a reference to a resource which matches the chained parameter value. Values for this field should be drawn from SearchParameter.code for a parameter on the target resource type.

Comments: Notes:

Not all systems will declare chain values. If no chain values are specified at all, then no presumptions can be made about the degree of chaining support available
A server may use a single chain value of '*' to mean that all reference search types supported can be chained rather than enumerating all chain values
If a particular reference search parameter is supported, but not subsequent chaining, then just list that search parameter name - e.g. for Patient.practitioner, the chain value would be practitioner
If a particular reference search parameter is supported with unlimited chaining beneath it, then follow the search parameter name with '.'. E.g. practitioner.
If there are specific (not unlimited) chaining paths allowed they can be explicitly enumerated. E.g. practitioner.organization

Conditions: spd-2

Cardinality: 0..*

Type: string

SearchParameter.component

For Composite resources to define the parts

Definition: Used to define the parts of a composite search parameter.

Cardinality: 0..*

Type: BackboneElement

SearchParameter.component.definition

Defines how the part works

Definition: The definition of the search parameter that describes this part.

Cardinality: 1..1

Type: canonical

SearchParameter.component.expression

Sub-expression relative to main expression

Definition: A sub-expression that defines how to extract values for this component from the output of the main SearchParameter.expression.

Comments: This expression overrides the expression in the definition and extracts the index values from the outcome of the composite expression.

Cardinality: 1..1

Type: string