--- type: "resource" title: "EvidenceVariable" resource: "EvidenceVariable" --- # EvidenceVariable ## Introduction ## Scope and Usage **This resource is a _definition_ resource from a FHIR workflow perspective** - see [Workflow](workflow), specifically [Definition](workflow#definition). The scope of the EvidenceVariable Resource is to describe an element that knowledge (evidence) is about. The EvidenceVariable Resources are expected to be used with [Evidence](evidence) Resources to facilitate searching and knowledge representation. Evidence may be reported for different types of knowledge. One commonly used format for expression of what evidence is about is the "PICO" format. PICO stands for: Population - the population within which exposures and outcomes are being considered Intervention - the conditional state or exposure state being described for which one is expressing the risk of or effect on an outcome Comparison - the alternative conditional state or alternative exposure state when one is comparing states for the effect on an outcome Outcome - the result or effect of an intervention or exposure in a population PICO (and its variants like PECO using E for Exposure or PICOT adding T for Timing) is a universal acronym used in evidence-based medicine communities to clearly express research questions and evidence findings. The EvidenceVariable Resource allows expression of the components of a PICO question in codeable and reusable formats. The EvidenceVariable.definition element has a CodeableReference datatype which can define the PICO component as a concept and/or reference to a Group Resource. The EvidenceVariable Resource is also used within [ResearchStudy](researchstudy) to describe the endpoint for an outcome measure. ## Boundaries and Relationships The Resource describing evidence findings ([Evidence](evidence)) will reference EvidenceVariable to describe what the evidence findings are about. The Resource describing a research study protocol ([ResearchStudy](researchstudy)) will reference EvidenceVariable to describe the endpoint for an outcome measure. ## Background and Context This resource may describe the intervention or exposure for which an evidence summary is applicable, or may describe the outcome or measured variable that an evidence summary is about. These descriptions could be used in coded specifications of recommendations from clinical practice guidelines to facilitate the translation from guidelines to clinical decision support artifacts. These descriptions could be used in Summary of Findings tables from systematic reviews to facilitate the representation of medical knowledge when creating recommendations. These descriptions could be used in classification of new evidence reports to facilitate recognition of signal for updating existing evidence summaries and recommendations. ## StructureDefinition ### Elements (Simplified) - **[EvidenceVariable](/evidencevariable-definitions#EvidenceVariable)** [0..*]: - A definition of an exposure, outcome, or other variable - **[EvidenceVariable.url](/evidencevariable-definitions#EvidenceVariable.url)** [0..1]: [uri](/uri) Canonical identifier for this evidence variable, represented as a URI (globally unique) - **[EvidenceVariable.identifier](/evidencevariable-definitions#EvidenceVariable.identifier)** [0..*]: [Identifier](/Identifier) Additional identifier for the evidence variable - **[EvidenceVariable.version](/evidencevariable-definitions#EvidenceVariable.version)** [0..1]: [string](/string) Business version of the evidence variable - **[EvidenceVariable.versionAlgorithm[x]](/evidencevariable-definitions#EvidenceVariable.versionAlgorithm%5Bx%5D)** [0..1]: [string](/string), [Coding](/Coding) extensible:[version-algorithm](/valueset-version-algorithm) How to compare versions - **[EvidenceVariable.name](/evidencevariable-definitions#EvidenceVariable.name)** [0..1]: [string](/string) Name for this evidence variable (computer friendly) - **[EvidenceVariable.title](/evidencevariable-definitions#EvidenceVariable.title)** [0..1]: [string](/string) Name for this evidence variable (human friendly) - **[EvidenceVariable.shortTitle](/evidencevariable-definitions#EvidenceVariable.shortTitle)** [0..1]: [string](/string) Title for use in informal contexts - **[EvidenceVariable.citeAs](/evidencevariable-definitions#EvidenceVariable.citeAs)** [0..1]: [markdown](/markdown) Display of how to cite this EvidenceVariable - **[EvidenceVariable.status](/evidencevariable-definitions#EvidenceVariable.status)** [1..1]: [code](/code) required:[publication-status](/valueset-publication-status) draft | active | retired | unknown - **[EvidenceVariable.experimental](/evidencevariable-definitions#EvidenceVariable.experimental)** [0..1]: [boolean](/boolean) For testing only - never for real usage - **[EvidenceVariable.date](/evidencevariable-definitions#EvidenceVariable.date)** [0..1]: [dateTime](/dateTime) Date last changed - **[EvidenceVariable.author](/evidencevariable-definitions#EvidenceVariable.author)** [0..*]: [ContactDetail](/ContactDetail) Who authored the content - **[EvidenceVariable.publisher](/evidencevariable-definitions#EvidenceVariable.publisher)** [0..1]: [string](/string) Name of the publisher/steward (organization or individual) - **[EvidenceVariable.contact](/evidencevariable-definitions#EvidenceVariable.contact)** [0..*]: [ContactDetail](/ContactDetail) Contact details for the publisher - **[EvidenceVariable.recorder](/evidencevariable-definitions#EvidenceVariable.recorder)** [0..*]: [ContactDetail](/ContactDetail) Who entered the data for the evidence variable - **[EvidenceVariable.editor](/evidencevariable-definitions#EvidenceVariable.editor)** [0..*]: [ContactDetail](/ContactDetail) Who edited the content - **[EvidenceVariable.reviewer](/evidencevariable-definitions#EvidenceVariable.reviewer)** [0..*]: [ContactDetail](/ContactDetail) Who reviewed the content - **[EvidenceVariable.endorser](/evidencevariable-definitions#EvidenceVariable.endorser)** [0..*]: [ContactDetail](/ContactDetail) Who endorsed the content - **[EvidenceVariable.description](/evidencevariable-definitions#EvidenceVariable.description)** [0..1]: [markdown](/markdown) Natural language description of the evidence variable - **[EvidenceVariable.note](/evidencevariable-definitions#EvidenceVariable.note)** [0..*]: [Annotation](/Annotation) Used for footnotes or explanatory notes - **[EvidenceVariable.useContext](/evidencevariable-definitions#EvidenceVariable.useContext)** [0..*]: [UsageContext](/UsageContext) The context that the content is intended to support - **[EvidenceVariable.purpose](/evidencevariable-definitions#EvidenceVariable.purpose)** [0..1]: [markdown](/markdown) Why this EvidenceVariable is defined - **[EvidenceVariable.copyright](/evidencevariable-definitions#EvidenceVariable.copyright)** [0..1]: [markdown](/markdown) Intellectual property ownership, may include restrictions on use - **[EvidenceVariable.copyrightLabel](/evidencevariable-definitions#EvidenceVariable.copyrightLabel)** [0..1]: [string](/string) Copyright holder and year(s) - **[EvidenceVariable.approvalDate](/evidencevariable-definitions#EvidenceVariable.approvalDate)** [0..1]: [date](/date) When the resource was approved by publisher - **[EvidenceVariable.lastReviewDate](/evidencevariable-definitions#EvidenceVariable.lastReviewDate)** [0..1]: [date](/date) When the resource was last reviewed by the publisher - **[EvidenceVariable.effectivePeriod](/evidencevariable-definitions#EvidenceVariable.effectivePeriod)** [0..1]: [Period](/Period) When the resource is expected to be used - **[EvidenceVariable.relatesTo](/evidencevariable-definitions#EvidenceVariable.relatesTo)** [0..*]: [BackboneElement](/BackboneElement) Relationships to other Resources - **[EvidenceVariable.relatesTo.type](/evidencevariable-definitions#EvidenceVariable.relatesTo.type)** [1..1]: [CodeableConcept](/CodeableConcept) extensible:[artifact-relationship-type](/valueset-artifact-relationship-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 - **[EvidenceVariable.relatesTo.target[x]](/evidencevariable-definitions#EvidenceVariable.relatesTo.target%5Bx%5D)** [1..1]: [uri](/uri), [Attachment](/Attachment), [canonical](/canonical), Reference([Resource](/Resource)), [markdown](/markdown) The artifact that is related to this EvidenceVariable - **[EvidenceVariable.actual](/evidencevariable-definitions#EvidenceVariable.actual)** [0..1]: [boolean](/boolean) Actual or conceptual - **[EvidenceVariable.definition](/evidencevariable-definitions#EvidenceVariable.definition)** [0..1]: [CodeableReference](/CodeableReference) example:[evidence-variable-definition](/valueset-evidence-variable-definition) The meaning of the evidence variable - **[EvidenceVariable.definitionModifier](/evidencevariable-definitions#EvidenceVariable.definitionModifier)** [0..*]: [BackboneElement](/BackboneElement) Further specification of the definition - **[EvidenceVariable.definitionModifier.code](/evidencevariable-definitions#EvidenceVariable.definitionModifier.code)** [1..1]: [CodeableConcept](/CodeableConcept) example:[evidence-variable-definition-modifier-code](/valueset-evidence-variable-definition-modifier-code) Attribute of the definition - **[EvidenceVariable.definitionModifier.value[x]](/evidencevariable-definitions#EvidenceVariable.definitionModifier.value%5Bx%5D)** [1..1]: [CodeableConcept](/CodeableConcept), [boolean](/boolean), [Quantity](/Quantity), [Range](/Range), [Period](/Period), [RelativeTime](/RelativeTime), Reference([Resource](/Resource)), [Expression](/Expression), [uri](/uri) Specification of the definition attribute - **[EvidenceVariable.handling](/evidencevariable-definitions#EvidenceVariable.handling)** [0..1]: [CodeableConcept](/CodeableConcept) example:[variable-handling-example](/valueset-variable-handling-example) boolean | continuous | dichotomous | ordinal | polychotomous | time-to-event | not-specified - **[EvidenceVariable.category](/evidencevariable-definitions#EvidenceVariable.category)** [0..*]: [BackboneElement](/BackboneElement) A grouping for dichotomous, ordinal, or polychotomouos variables - **[EvidenceVariable.category.name](/evidencevariable-definitions#EvidenceVariable.category.name)** [0..1]: [string](/string) Description of the grouping - **[EvidenceVariable.category.value[x]](/evidencevariable-definitions#EvidenceVariable.category.value%5Bx%5D)** [0..1]: [CodeableConcept](/CodeableConcept), [Quantity](/Quantity), [Range](/Range), Reference([Group](/Group)) Definition of the grouping - **[EvidenceVariable.conditional](/evidencevariable-definitions#EvidenceVariable.conditional)** [0..1]: [Expression](/Expression) Condition determining whether the data will be collected - **[EvidenceVariable.classifier](/evidencevariable-definitions#EvidenceVariable.classifier)** [0..*]: [CodeableConcept](/CodeableConcept) example:[evidence-variable-classifier](/valueset-evidence-variable-classifier) Classification - **[EvidenceVariable.dataStorage](/evidencevariable-definitions#EvidenceVariable.dataStorage)** [0..*]: [BackboneElement](/BackboneElement) How the data element (value of the variable) is found - **[EvidenceVariable.dataStorage.datatype](/evidencevariable-definitions#EvidenceVariable.dataStorage.datatype)** [0..1]: [CodeableConcept](/CodeableConcept) preferred:[fhir-types](/valueset-fhir-types) Type of data used to express value of the variable - **[EvidenceVariable.dataStorage.path](/evidencevariable-definitions#EvidenceVariable.dataStorage.path)** [0..1]: [string](/string) Where to find the data element in the dataset - **[EvidenceVariable.dataStorage.delimiter](/evidencevariable-definitions#EvidenceVariable.dataStorage.delimiter)** [0..1]: [string](/string) Character(s) separating values in a string-based list - **[EvidenceVariable.dataStorage.component](/evidencevariable-definitions#EvidenceVariable.dataStorage.component)** [0..*]: - - **[EvidenceVariable.timing](/evidencevariable-definitions#EvidenceVariable.timing)** [0..1]: [RelativeTime](/RelativeTime) When the variable is observed - **[EvidenceVariable.period](/evidencevariable-definitions#EvidenceVariable.period)** [0..1]: [Period](/Period) Calendar-based timing when the variable is observed - **[EvidenceVariable.constraint](/evidencevariable-definitions#EvidenceVariable.constraint)** [0..*]: [BackboneElement](/BackboneElement) Limit on acceptability of data value - **[EvidenceVariable.constraint.conditional](/evidencevariable-definitions#EvidenceVariable.constraint.conditional)** [0..1]: [CodeableConcept](/CodeableConcept) example:[administrative-gender](/valueset-administrative-gender) Condition determining whether this constraint applies - **[EvidenceVariable.constraint.minimumQuantity](/evidencevariable-definitions#EvidenceVariable.constraint.minimumQuantity)** [0..1]: [Quantity](/Quantity) The lowest permissible value of the variable - **[EvidenceVariable.constraint.maximumQuantity](/evidencevariable-definitions#EvidenceVariable.constraint.maximumQuantity)** [0..1]: [Quantity](/Quantity) The highest permissible value of the variable - **[EvidenceVariable.constraint.earliestDateTime](/evidencevariable-definitions#EvidenceVariable.constraint.earliestDateTime)** [0..1]: [dateTime](/dateTime) The earliest permissible value of the variable - **[EvidenceVariable.constraint.latestDateTime](/evidencevariable-definitions#EvidenceVariable.constraint.latestDateTime)** [0..1]: [dateTime](/dateTime) The latest permissible value of the variable - **[EvidenceVariable.constraint.minimumStringLength](/evidencevariable-definitions#EvidenceVariable.constraint.minimumStringLength)** [0..1]: [unsignedInt](/unsignedInt) The lowest number of characters allowed for a value of the variable - **[EvidenceVariable.constraint.maximumStringLength](/evidencevariable-definitions#EvidenceVariable.constraint.maximumStringLength)** [0..1]: [positiveInt](/positiveInt) The highest number of characters allowed for a value of the variable - **[EvidenceVariable.constraint.code](/evidencevariable-definitions#EvidenceVariable.constraint.code)** [0..1]: [CodeableConcept](/CodeableConcept) example:[evidence-variable-constraint](/valueset-evidence-variable-constraint) Rule for acceptable data values - **[EvidenceVariable.constraint.expression](/evidencevariable-definitions#EvidenceVariable.constraint.expression)** [0..1]: [Expression](/Expression) Rule for acceptable data values, as an Expression - **[EvidenceVariable.constraint.expectedValueSet](/evidencevariable-definitions#EvidenceVariable.constraint.expectedValueSet)** [0..1]: Reference([ValueSet](/ValueSet)) List of anticipated values used to express value of the variable - **[EvidenceVariable.constraint.expectedUnitsValueSet](/evidencevariable-definitions#EvidenceVariable.constraint.expectedUnitsValueSet)** [0..1]: Reference([ValueSet](/ValueSet)) List of anticipated values used to express units for the value of the variable - **[EvidenceVariable.constraint.anyValueAllowed](/evidencevariable-definitions#EvidenceVariable.constraint.anyValueAllowed)** [0..1]: [boolean](/boolean) Permissibility of unanticipated value used to express value of the variable - **[EvidenceVariable.missingDataMeaning](/evidencevariable-definitions#EvidenceVariable.missingDataMeaning)** [0..*]: [CodeableConcept](/CodeableConcept) example:[data-absent-reason](/valueset-data-absent-reason) How missing data can be interpreted - **[EvidenceVariable.unacceptableDataHandling](/evidencevariable-definitions#EvidenceVariable.unacceptableDataHandling)** [0..*]: [CodeableConcept](/CodeableConcept) example:[evidence-variable-unacceptable-data-handling](/valueset-evidence-variable-unacceptable-data-handling) How erroneous data is processed ## Mappings - [EvidenceVariable Mappings](/evidencevariable-mappings) — 14 mapping entries ## Resource Packs ### list-EvidenceVariable-packs.xml ```xml ``` ## Search Parameters - [context](/evidencevariable-search#context) — **token** — A use context assigned to the evidence variable — `(EvidenceVariable.useContext.value.ofType(CodeableConcept))` - [context-quantity](/evidencevariable-search#context-quantity) — **quantity** — A quantity- or range-valued use context assigned to the evidence variable — `(EvidenceVariable.useContext.value.ofType(Quantity)) | (EvidenceVariable.useContext.value.ofType(Range))` - [context-type](/evidencevariable-search#context-type) — **token** — A type of use context assigned to the evidence variable — `EvidenceVariable.useContext.code` - [context-type-quantity](/evidencevariable-search#context-type-quantity) — **composite** — A use context type and quantity- or range-based value assigned to the evidence variable — `EvidenceVariable.useContext` - [context-type-value](/evidencevariable-search#context-type-value) — **composite** — A use context type and value assigned to the evidence variable — `EvidenceVariable.useContext` - [date](/evidencevariable-search#date) — **date** — The evidence variable publication date — `EvidenceVariable.date` - [description](/evidencevariable-search#description) — **string** — The description of the evidence variable — `EvidenceVariable.description` - [identifier](/evidencevariable-search#identifier) — **token** — External identifier for the evidence variable — `EvidenceVariable.identifier` - [name](/evidencevariable-search#name) — **string** — Computationally friendly name of the evidence variable — `EvidenceVariable.name` - [publisher](/evidencevariable-search#publisher) — **string** — Name of the publisher of the evidence variable — `EvidenceVariable.publisher` - [status](/evidencevariable-search#status) — **token** — The current status of the evidence variable — `EvidenceVariable.status` - [title](/evidencevariable-search#title) — **string** — The human-friendly name of the evidence variable — `EvidenceVariable.title` - [topic](/evidencevariable-search#topic) — **token** — Topics associated with the EvidenceVariable — `-` - [url](/evidencevariable-search#url) — **uri** — The uri that identifies the evidence variable — `EvidenceVariable.url` - [version](/evidencevariable-search#version) — **token** — The business version of the evidence variable — `EvidenceVariable.version` - [experimental](/evidencevariable-search#experimental) — **token** — Whether the EvidenceVariable is experimental — `EvidenceVariable.experimental` [Full Search Parameters](/evidencevariable-search) ## Examples - [evidencevariable-example](/evidencevariable-example-evidencevariable-example) — evidencevariable-example - [evidencevariable-example-alive-independent-90day](/evidencevariable-example-evidencevariable-example-alive-independent-90day) — evidencevariable-example-alive-independent-90day - [evidencevariable-example-alteplase-for-stroke](/evidencevariable-example-evidencevariable-example-alteplase-for-stroke) — evidencevariable-example-alteplase-for-stroke - [evidencevariable-example-dead-or-dependent-90day](/evidencevariable-example-evidencevariable-example-dead-or-dependent-90day) — evidencevariable-example-dead-or-dependent-90day - [evidencevariable-example-fatal-ICH-in-7-days](/evidencevariable-example-evidencevariable-example-fatal-ICH-in-7-days) — evidencevariable-example-fatal-ICH-in-7-days - [evidencevariable-example-group-assignment](/evidencevariable-example-evidencevariable-example-group-assignment) — evidencevariable-example-group-assignment - [evidencevariable-example-mRS0-2-at-90days](/evidencevariable-example-evidencevariable-example-mRS0-2-at-90days) — evidencevariable-example-mRS0-2-at-90days - [evidencevariable-example-mRS3-6-at-90days](/evidencevariable-example-evidencevariable-example-mRS3-6-at-90days) — evidencevariable-example-mRS3-6-at-90days - [evidencevariable-example-no-alteplase](/evidencevariable-example-evidencevariable-example-no-alteplase) — evidencevariable-example-no-alteplase - [evidencevariable-example-outcome-death-or-major-injury](/evidencevariable-example-evidencevariable-example-outcome-death-or-major-injury) — evidencevariable-example-outcome-death-or-major-injury - [evidencevariable-example-participant-flow](/evidencevariable-example-evidencevariable-example-participant-flow) — evidencevariable-example-participant-flow - [evidencevariable-example-placebo](/evidencevariable-example-evidencevariable-example-placebo) — evidencevariable-example-placebo - [evidencevariable-examples-header](/evidencevariable-example-evidencevariable-examples-header) — evidencevariable-examples-header - [example-alive-independent-90day](/evidencevariable-example-example-alive-independent-90day) — evidencevariable-example-alive-independent-90day — Alive and not functionally dependent 90 days - [example-alteplase-for-stroke](/evidencevariable-example-example-alteplase-for-stroke) — evidencevariable-example-alteplase-for-stroke — Alteplase for Stroke - [example-dead-or-dependent-90day](/evidencevariable-example-example-dead-or-dependent-90day) — evidencevariable-example-dead-or-dependent-90day — Dead or functionally dependent at 90 days - [example-fatal-ICH-in-7-days](/evidencevariable-example-example-fatal-ICH-in-7-days) — evidencevariable-example-fatal-ICH-in-7-days — Fatal Intracranial Hemorrhage Within Seven Days - [example-group-assignment](/evidencevariable-example-example-group-assignment) — evidencevariable-example-group-assignment — GroupAssignment: PARACHUTE Trial jumping from aircraft with parachute vs. empty backpack - [example-mRS0-2-at-90days](/evidencevariable-example-example-mRS0-2-at-90days) — evidencevariable-example-mRS0-2-at-90days — Modified Rankin Scale score 0-2 at 90 days after treatment - [example-mRS3-6-at-90days](/evidencevariable-example-example-mRS3-6-at-90days) — evidencevariable-example-mRS3-6-at-90days — Modified Rankin Scale score 3-6 at 90 days after treatment - [example-no-alteplase](/evidencevariable-example-example-no-alteplase) — evidencevariable-example-no-alteplase — No Alteplase - [example-outcome-death-or-major-injury](/evidencevariable-example-example-outcome-death-or-major-injury) — evidencevariable-example-outcome-death-or-major-injury — Outcome: Death or Major Traumatic Injury on Impact - [example-participant-flow](/evidencevariable-example-example-participant-flow) — evidencevariable-example-participant-flow — ParticipantFlowEvidenceVariable: PARACHUTE Trial Participants that declined randomization - [example-placebo](/evidencevariable-example-example-placebo) — evidencevariable-example-placebo — Placebo [Full Examples](/evidencevariable-examples) ## Mapping Exceptions ### evidencevariable-fivews-mapping-exceptions.xml ### Unmapped Elements - **FiveWs.what** — Unknown - **FiveWs.actor** — Unknown - **FiveWs.cause** — Unknown - **FiveWs.class** — Unknown - **FiveWs.where** — Unknown - **FiveWs.context** — Unknown - **FiveWs.init** — Unknown - **FiveWs.source** — Unknown - **FiveWs.who** — Unknown - **FiveWs.grade** — Unknown - **FiveWs.planned** — Unknown - **FiveWs.done** — Unknown - **FiveWs.subject** — Unknown