---
type: "resource-definitions"
title: "EvidenceVariable Definitions"
resource: "EvidenceVariable"
---

# EvidenceVariable Definitions

<a id="EvidenceVariable"></a>

## EvidenceVariable
A definition of an exposure, outcome, or other variable

**Definition:** The EvidenceVariable resource describes an element that knowledge (Evidence) is about.

**Comments:** The EvidenceVariable may be an exposure variable (intervention, condition, or state), a measured variable (outcome or observed parameter), or other variable (such as confounding factor).

**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]([A-Za-z0-9_]){1,254}$')

**Mappings:** w5=clinical.general


<a id="EvidenceVariable.url"></a>

## EvidenceVariable.url
Canonical identifier for this evidence variable, represented as a URI (globally unique)

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

**Comments:** 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 evidence variable to be referenced by a single globally unique identifier.

**Cardinality:** 0..1

**Type:** [uri](/uri)

**Summary:** true

**Constraints:** cnl-1 | warning | URL should not contain | or # - these characters make processing canonical references problematic | exists() implies matches('^[^|# ]+$')

**Mappings:** w5=FiveWs.identifier


<a id="EvidenceVariable.identifier"></a>

## EvidenceVariable.identifier
Additional identifier for the evidence variable

**Definition:** A formal identifier that is used to identify this evidence variable 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](/Identifier)

**Summary:** true

**Mappings:** w5=FiveWs.identifier; objimpl=no-gen-base


<a id="EvidenceVariable.version"></a>

## EvidenceVariable.version
Business version of the evidence variable

**Definition:** The identifier that is used to identify this version of the evidence variable when it is referenced in a specification, model, design or instance. This is an arbitrary value managed by the evidence variable 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. To provide a version consistent with the Decision Support Service specification, use the format Major.Minor.Revision (e.g. 1.0.0). For more information on versioning knowledge assets, refer to the Decision Support Service specification. Note that a version is required for non-experimental active artifacts.

**Comments:** There may be different evidence variable 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 evidence variable with the format [url]|[version]. The version SHOULD NOT contain a '#' - see [Business Version](resource.html#bv-format).

**Cardinality:** 0..1

**Type:** [string](/string)

**Summary:** true

**Mappings:** w5=FiveWs.version


<a id="EvidenceVariable.versionAlgorithm[x]"></a>

## EvidenceVariable.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 is newer, and a 0 if the version ordering can't successfully be determined.

**Cardinality:** 0..1

**Type:** [string](/string), [Coding](/Coding)

**Binding:** extensible:[version-algorithm](/valueset-version-algorithm)

**Summary:** true


<a id="EvidenceVariable.name"></a>

## EvidenceVariable.name
Name for this evidence variable (computer friendly)

**Definition:** A natural language name identifying the evidence variable. 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:** 0..1

**Type:** [string](/string)

**Summary:** true


<a id="EvidenceVariable.title"></a>

## EvidenceVariable.title
Name for this evidence variable (human friendly)

**Definition:** A short, descriptive, user-friendly title for the evidence variable.

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

**Cardinality:** 0..1

**Type:** [string](/string)

**Summary:** true


<a id="EvidenceVariable.shortTitle"></a>

## EvidenceVariable.shortTitle
Title for use in informal contexts

**Definition:** The short title provides an alternate title for use in informal descriptive contexts where the full, formal title is not necessary.

**Requirements:** Need to be able to reference the content by a short description, but still provide a longer, more formal title for the content.

**Cardinality:** 0..1

**Type:** [string](/string)

**Summary:** true


<a id="EvidenceVariable.citeAs"></a>

## EvidenceVariable.citeAs
Display of how to cite this EvidenceVariable

**Definition:** Display of the suggested method of how to cite this EvidenceVariable.

**Cardinality:** 0..1

**Type:** [markdown](/markdown)


<a id="EvidenceVariable.status"></a>

## EvidenceVariable.status
draft | active | retired | unknown

**Definition:** The status of this EvidenceVariable. Enables tracking the life-cycle of the content.

**Comments:** Allows filtering of evidence variables that are appropriate for use versus not.

See guidance around (not) making local changes to elements [here](canonicalresource.html#localization).

**Cardinality:** 1..1

**Type:** [code](/code)

**Binding:** required:[publication-status](/valueset-publication-status)

**Summary:** true

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

**Mappings:** w5=FiveWs.status


<a id="EvidenceVariable.experimental"></a>

## EvidenceVariable.experimental
For testing only - never for real usage

**Definition:** A Boolean value to indicate that this resource 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 artifacts that are appropriate for use versus not. Experimental resources might include example instances in implementation guides, instances created solely for testing purposes, etc. If experimental is 'true' for any version of a resource, it should be true for all versions of the resource.  (If experimental changes, then it is being misused or a resource that was never intended for real-world use has unexpectedly changed its purpose.).

Experimental resources are not expected to be stable and may well have breaking changes without a corresponding change to the 'version' element.

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

**Cardinality:** 0..1

**Type:** [boolean](/boolean)


<a id="EvidenceVariable.date"></a>

## EvidenceVariable.date
Date last changed

**Definition:** The date  (and optionally time) when the evidence variable 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 evidence variable 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 evidence variable. 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](canonicalresource.html#localization).

**Aliases:** Revision Date

**Cardinality:** 0..1

**Type:** [dateTime](/dateTime)

**Summary:** true

**Mappings:** w5=FiveWs.recorded


<a id="EvidenceVariable.author"></a>

## EvidenceVariable.author
Who authored the content

**Definition:** An individiual or organization primarily involved in the creation and maintenance of the content.

**Comments:** Extensions to ContactDetail include: contactReference, contactAddress, and contributionTime (see [Clinical Reasoning Module](clinicalreasoning-module.html)).

**Cardinality:** 0..*

**Type:** [ContactDetail](/ContactDetail)

**Mappings:** w5=FiveWs.author; rim=.participation[typeCode=AUT]


<a id="EvidenceVariable.publisher"></a>

## EvidenceVariable.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 evidence variable.

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

**Requirements:** Helps establish the "authority/credibility" of the evidence variable.  May also allow for contact.

**Cardinality:** 0..1

**Type:** [string](/string)

**Summary:** true

**Mappings:** w5=FiveWs.witness


<a id="EvidenceVariable.contact"></a>

## EvidenceVariable.contact
Contact details for the publisher

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

**Comments:** Extensions to ContactDetail include: contactReference, contactAddress, and contributionTime (see [Clinical Reasoning Module](clinicalreasoning-module.html)).

See guidance around (not) making local changes to elements [here](canonicalresource.html#localization).

**Cardinality:** 0..*

**Type:** [ContactDetail](/ContactDetail)

**Summary:** true


<a id="EvidenceVariable.recorder"></a>

## EvidenceVariable.recorder
Who entered the data for the evidence variable

**Definition:** The person or entity that entered the data into the EvidenceVariable Resource instance, if different than the author or creator of the intellectual property contained within the EvidenceVariable Resource instance.

**Comments:** The EvidenceVariable.recorder element is structured to support a name (with a string datatype) and contact point information for the recorder, and is not structured to support unique identifiers for the recorder. If detailed contributorship data is needed, then one can create a Citation Resource for the EvidenceVariable Resource.

**Cardinality:** 0..*

**Type:** [ContactDetail](/ContactDetail)


<a id="EvidenceVariable.editor"></a>

## EvidenceVariable.editor
Who edited the content

**Definition:** An individual or organization primarily responsible for internal coherence of the content.

**Comments:** Extensions to ContactDetail include: contactReference, contactAddress, and contributionTime (see [Clinical Reasoning Module](clinicalreasoning-module.html)).

**Cardinality:** 0..*

**Type:** [ContactDetail](/ContactDetail)


<a id="EvidenceVariable.reviewer"></a>

## EvidenceVariable.reviewer
Who reviewed the content

**Definition:** An individual or organization asserted by the publisher to be primarily responsible for review of some aspect of the content.

**Comments:** Extensions to ContactDetail include: contactReference, contactAddress, and contributionTime (see [Clinical Reasoning Module](clinicalreasoning-module.html)).

See guidance around (not) making local changes to elements [here](canonicalresource.html#localization).

**Cardinality:** 0..*

**Type:** [ContactDetail](/ContactDetail)

**Mappings:** rim=.participation[typeCode=VRF] {not clear whether VRF best corresponds to reviewer or endorser}


<a id="EvidenceVariable.endorser"></a>

## EvidenceVariable.endorser
Who endorsed the content

**Definition:** An individual or organization asserted by the publisher to be responsible for officially endorsing the content for use in some setting.

**Comments:** Extensions to ContactDetail include: contactReference, contactAddress, and contributionTime (see [Clinical Reasoning Module](clinicalreasoning-module.html)).

See guidance around (not) making local changes to elements [here](canonicalresource.html#localization).

**Cardinality:** 0..*

**Type:** [ContactDetail](/ContactDetail)

**Mappings:** rim=.participation[typeCode=VRF] {not clear whether VRF best corresponds to reviewer or endorser}


<a id="EvidenceVariable.description"></a>

## EvidenceVariable.description
Natural language description of the evidence variable

**Definition:** A natural language summary of the evidence variable.

**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 evidence variable 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 evidence variable is presumed to be the predominant language in the place the evidence variable was created).

**Cardinality:** 0..1

**Type:** [markdown](/markdown)

**Summary:** true


<a id="EvidenceVariable.note"></a>

## EvidenceVariable.note
Used for footnotes or explanatory notes

**Definition:** A human-readable string to clarify or explain concepts about the resource.

**Cardinality:** 0..*

**Type:** [Annotation](/Annotation)


<a id="EvidenceVariable.useContext"></a>

## EvidenceVariable.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 evidence variable 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](/UsageContext)

**Summary:** true


<a id="EvidenceVariable.purpose"></a>

## EvidenceVariable.purpose
Why this EvidenceVariable is defined

**Definition:** Explanation of why this EvidenceVariable is needed and why it has been designed as it has.

**Comments:** This element does not describe the usage of the EvidenceVariable. 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 EvidenceVariable.

**Cardinality:** 0..1

**Type:** [markdown](/markdown)

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


<a id="EvidenceVariable.copyright"></a>

## EvidenceVariable.copyright
Intellectual property ownership, may include restrictions on use

**Definition:** A copyright statement relating to the EvidenceVariable and/or its contents. Copyright statements are legal notices of intellectual property ownership and may include restrictions on the use and publishing of the EvidenceVariable.

**Cardinality:** 0..1

**Type:** [markdown](/markdown)


<a id="EvidenceVariable.copyrightLabel"></a>

## EvidenceVariable.copyrightLabel
Copyright holder and year(s)

**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](/string)


<a id="EvidenceVariable.approvalDate"></a>

## EvidenceVariable.approvalDate
When the resource was approved by publisher

**Definition:** The date on which the resource content was approved by the publisher. Approval happens once when the content is officially approved for usage.

See guidance around (not) making local changes to elements [here](canonicalresource.html#localization).

**Cardinality:** 0..1

**Type:** [date](/date)


<a id="EvidenceVariable.lastReviewDate"></a>

## EvidenceVariable.lastReviewDate
When the resource was last reviewed by the publisher

**Definition:** The date on which the resource content was last reviewed. Review happens periodically after approval but does not change the original approval date.

**Comments:** If specified, this date follows the original approval date.

See guidance around (not) making local changes to elements [here](canonicalresource.html#localization).

**Cardinality:** 0..1

**Type:** [date](/date)


<a id="EvidenceVariable.effectivePeriod"></a>

## EvidenceVariable.effectivePeriod
When the resource is expected to be used

**Definition:** The period during which the resource content was or is planned to be in active use.

**Comments:** The effective period for an EvidenceVariable determines when the content is applicable for usage and is independent of publication and review dates. For example, a variable intended to be used for the year 2016 might be published in 2015.

See guidance around (not) making local changes to elements [here](canonicalresource.html#localization).

**Cardinality:** 0..1

**Type:** [Period](/Period)


<a id="EvidenceVariable.relatesTo"></a>

## EvidenceVariable.relatesTo
Relationships to other Resources

**Definition:** Relationships that this EvidenceVariable has with other FHIR or non-FHIR resources that already exist.

**Cardinality:** 0..*

**Type:** [BackboneElement](/BackboneElement)


<a id="EvidenceVariable.relatesTo.type"></a>

## EvidenceVariable.relatesTo.type
documentation | justification | citation | predecessor | successor | derived-from | depends-on | composed-of | part-of | amends | amended-with | appends | appended-with | cites | cited-by | comments-on | comment-in | contains | contained-in | corrects | correction-in | replaces | replaced-with | retracts | retracted-by | signs | similar-to | supports | supported-with | transforms | transformed-into | transformed-with | documents | specification-of | created-with | cite-as | reprint | reprint-of | summarizes

**Definition:** The type of relationship to the related artifact.

**Cardinality:** 1..1

**Type:** [CodeableConcept](/CodeableConcept)

**Binding:** extensible:[artifact-relationship-type](/valueset-artifact-relationship-type)


<a id="EvidenceVariable.relatesTo.target[x]"></a>

## EvidenceVariable.relatesTo.target[x]
The artifact that is related to this EvidenceVariable

**Definition:** The artifact that is related to this EvidenceVariable Resource.

**Cardinality:** 1..1

**Type:** [uri](/uri), [Attachment](/Attachment), [canonical](/canonical), Reference([Resource](/Resource)), [markdown](/markdown)


<a id="EvidenceVariable.actual"></a>

## EvidenceVariable.actual
Actual or conceptual

**Definition:** True if the actual variable measured, false if a conceptual representation of the intended variable.

**Meaning if Missing:** Value is unknown.

**Cardinality:** 0..1

**Type:** [boolean](/boolean)


<a id="EvidenceVariable.definition"></a>

## EvidenceVariable.definition
The meaning of the evidence variable

**Cardinality:** 0..1

**Type:** [CodeableReference](/CodeableReference)

**Binding:** example:[evidence-variable-definition](/valueset-evidence-variable-definition)

**Summary:** true


<a id="EvidenceVariable.definitionModifier"></a>

## EvidenceVariable.definitionModifier
Further specification of the definition

**Cardinality:** 0..*

**Type:** [BackboneElement](/BackboneElement)


<a id="EvidenceVariable.definitionModifier.code"></a>

## EvidenceVariable.definitionModifier.code
Attribute of the definition

**Cardinality:** 1..1

**Type:** [CodeableConcept](/CodeableConcept)

**Binding:** example:[evidence-variable-definition-modifier-code](/valueset-evidence-variable-definition-modifier-code)


<a id="EvidenceVariable.definitionModifier.value[x]"></a>

## EvidenceVariable.definitionModifier.value[x]
Specification of the definition attribute

**Cardinality:** 1..1

**Type:** [CodeableConcept](/CodeableConcept), [boolean](/boolean), [Quantity](/Quantity), [Range](/Range), [Period](/Period), [RelativeTime](/RelativeTime), Reference([Resource](/Resource)), [Expression](/Expression), [uri](/uri)


<a id="EvidenceVariable.handling"></a>

## EvidenceVariable.handling
boolean | continuous | dichotomous | ordinal | polychotomous | time-to-event | not-specified

**Definition:** The method of handling in statistical analysis.

**Comments:** See the Evidence Based Medicine on FHIR Implementation Guide (https://hl7.org/fhir/uv/ebm) for Extensible and Preferred value sets for evidence-related terminologies.

**Cardinality:** 0..1

**Type:** [CodeableConcept](/CodeableConcept)

**Binding:** example:[variable-handling-example](/valueset-variable-handling-example)


<a id="EvidenceVariable.category"></a>

## EvidenceVariable.category
A grouping for dichotomous, ordinal, or polychotomouos variables

**Cardinality:** 0..*

**Type:** [BackboneElement](/BackboneElement)


<a id="EvidenceVariable.category.name"></a>

## EvidenceVariable.category.name
Description of the grouping

**Definition:** Description of the grouping.

**Cardinality:** 0..1

**Type:** [string](/string)


<a id="EvidenceVariable.category.value[x]"></a>

## EvidenceVariable.category.value[x]
Definition of the grouping

**Definition:** Definition of the grouping.

**Cardinality:** 0..1

**Type:** [CodeableConcept](/CodeableConcept), [Quantity](/Quantity), [Range](/Range), Reference([Group](/Group))


<a id="EvidenceVariable.conditional"></a>

## EvidenceVariable.conditional
Condition determining whether the data will be collected

**Definition:** The context, situation, or parameters that determine whether the data is obtained to determine the value of the variable.

**Cardinality:** 0..1

**Type:** [Expression](/Expression)


<a id="EvidenceVariable.classifier"></a>

## EvidenceVariable.classifier
Classification

**Definition:** Classification of the variable.

**Cardinality:** 0..*

**Type:** [CodeableConcept](/CodeableConcept)

**Binding:** example:[evidence-variable-classifier](/valueset-evidence-variable-classifier)


<a id="EvidenceVariable.dataStorage"></a>

## EvidenceVariable.dataStorage
How the data element (value of the variable) is found

**Definition:** How the data element is organized and where the data element (expressing the value of the variable) is found in the dataset.

**Cardinality:** 0..*

**Type:** [BackboneElement](/BackboneElement)


<a id="EvidenceVariable.dataStorage.datatype"></a>

## EvidenceVariable.dataStorage.datatype
Type of data used to express value of the variable

**Definition:** The type of data used to express values of the variable.

**Cardinality:** 0..1

**Type:** [CodeableConcept](/CodeableConcept)

**Binding:** preferred:[fhir-types](/valueset-fhir-types)


<a id="EvidenceVariable.dataStorage.path"></a>

## EvidenceVariable.dataStorage.path
Where to find the data element in the dataset

**Definition:** The mapping (order of elements) to reach the element containing the  data element in the dataset.

**Cardinality:** 0..1

**Type:** [string](/string)


<a id="EvidenceVariable.dataStorage.delimiter"></a>

## EvidenceVariable.dataStorage.delimiter
Character(s) separating values in a string-based list

**Definition:** A character or series of characters that is used within a string to signal the separation of discrete values.

**Comments:** The delimiter element SHOULD only be used when the datatype element is a string- or text-based datatype. The delimiter element is used when the data is stored in a string which contains a list or array of values.

**Cardinality:** 0..1

**Type:** [string](/string)


<a id="EvidenceVariable.dataStorage.component"></a>

## EvidenceVariable.dataStorage.component
**Definition:** A part of the value for a variable that is stored in 2 or more parts.

**Cardinality:** 0..*


<a id="EvidenceVariable.timing"></a>

## EvidenceVariable.timing
When the variable is observed

**Definition:** When the variable is observed in relation to a reference point in time defined by context or event.

**Cardinality:** 0..1

**Type:** [RelativeTime](/RelativeTime)


<a id="EvidenceVariable.period"></a>

## EvidenceVariable.period
Calendar-based timing when the variable is observed

**Definition:** When the variable is observed in relation to calendar dates and times.

**Cardinality:** 0..1

**Type:** [Period](/Period)


<a id="EvidenceVariable.constraint"></a>

## EvidenceVariable.constraint
Limit on acceptability of data value

**Definition:** Limit on acceptability of data used to express values of the variable.

**Cardinality:** 0..*

**Type:** [BackboneElement](/BackboneElement)


<a id="EvidenceVariable.constraint.conditional"></a>

## EvidenceVariable.constraint.conditional
Condition determining whether this constraint applies

**Definition:** The context, situation, or parameters that determine whether this constraint applies.

**Cardinality:** 0..1

**Type:** [CodeableConcept](/CodeableConcept)

**Binding:** example:[administrative-gender](/valueset-administrative-gender)


<a id="EvidenceVariable.constraint.minimumQuantity"></a>

## EvidenceVariable.constraint.minimumQuantity
The lowest permissible value of the variable

**Definition:** The lowest permissible value of the variable, used with variables that have a number-based datatype (with or without units).

**Cardinality:** 0..1

**Type:** [Quantity](/Quantity)


<a id="EvidenceVariable.constraint.maximumQuantity"></a>

## EvidenceVariable.constraint.maximumQuantity
The highest permissible value of the variable

**Definition:** The highest permissible value of the variable, used with variables that have a number-based datatype (with or without units).

**Cardinality:** 0..1

**Type:** [Quantity](/Quantity)


<a id="EvidenceVariable.constraint.earliestDateTime"></a>

## EvidenceVariable.constraint.earliestDateTime
The earliest permissible value of the variable

**Definition:** The earliest permissible value of the variable, used with variables that have a date-based or dateTime-based datatype.

**Cardinality:** 0..1

**Type:** [dateTime](/dateTime)


<a id="EvidenceVariable.constraint.latestDateTime"></a>

## EvidenceVariable.constraint.latestDateTime
The latest permissible value of the variable

**Definition:** The latest permissible value of the variable, used with variables that have a date-based or dateTime-based datatype.

**Cardinality:** 0..1

**Type:** [dateTime](/dateTime)


<a id="EvidenceVariable.constraint.minimumStringLength"></a>

## EvidenceVariable.constraint.minimumStringLength
The lowest number of characters allowed for a value of the variable

**Definition:** The lowest number of characters allowed for a value of the variable, used with variables that have a string-based datatype.

**Cardinality:** 0..1

**Type:** [unsignedInt](/unsignedInt)


<a id="EvidenceVariable.constraint.maximumStringLength"></a>

## EvidenceVariable.constraint.maximumStringLength
The highest number of characters allowed for a value of the variable

**Definition:** The highest number of characters allowed for a value of the variable, used with variables that have a string-based datatype.

**Cardinality:** 0..1

**Type:** [positiveInt](/positiveInt)


<a id="EvidenceVariable.constraint.code"></a>

## EvidenceVariable.constraint.code
Rule for acceptable data values

**Definition:** A rule, such as a format or other expectation, for the data values.

**Cardinality:** 0..1

**Type:** [CodeableConcept](/CodeableConcept)

**Binding:** example:[evidence-variable-constraint](/valueset-evidence-variable-constraint)


<a id="EvidenceVariable.constraint.expression"></a>

## EvidenceVariable.constraint.expression
Rule for acceptable data values, as an Expression

**Definition:** A rule, such as a format or other expectation, for the data values, expressed as an Expression.

**Cardinality:** 0..1

**Type:** [Expression](/Expression)


<a id="EvidenceVariable.constraint.expectedValueSet"></a>

## EvidenceVariable.constraint.expectedValueSet
List of anticipated values used to express value of the variable

**Definition:** List of anticipated values used to express value of the variable, used with variables that have a codeable concept-based datatype.

**Cardinality:** 0..1

**Type:** Reference([ValueSet](/ValueSet))


<a id="EvidenceVariable.constraint.expectedUnitsValueSet"></a>

## EvidenceVariable.constraint.expectedUnitsValueSet
List of anticipated values used to express units for the value of the variable

**Definition:** List of anticipated values used to express units for the value of the variable, used with variables that have a Quantity-based datatype.

**Cardinality:** 0..1

**Type:** Reference([ValueSet](/ValueSet))


<a id="EvidenceVariable.constraint.anyValueAllowed"></a>

## EvidenceVariable.constraint.anyValueAllowed
Permissibility of unanticipated value used to express value of the variable

**Definition:** Whether the value expressed for a variable is allowed to not be restricted to the expected value set.

**Meaning if Missing:** Presumed false.

**Cardinality:** 0..1

**Type:** [boolean](/boolean)


<a id="EvidenceVariable.missingDataMeaning"></a>

## EvidenceVariable.missingDataMeaning
How missing data can be interpreted

**Definition:** A method or transformation applied for missing data.

**Cardinality:** 0..*

**Type:** [CodeableConcept](/CodeableConcept)

**Binding:** example:[data-absent-reason](/valueset-data-absent-reason)


<a id="EvidenceVariable.unacceptableDataHandling"></a>

## EvidenceVariable.unacceptableDataHandling
How erroneous data is processed

**Definition:** A method or transformation applied for data that does not match required patterns.

**Cardinality:** 0..*

**Type:** [CodeableConcept](/CodeableConcept)

**Binding:** example:[evidence-variable-unacceptable-data-handling](/valueset-evidence-variable-unacceptable-data-handling)