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

# Evidence Definitions

<a id="Evidence"></a>

## Evidence
Single evidence bit

**Definition:** The Evidence Resource provides a machine-interpretable expression of an evidence concept including the evidence variables (e.g., population, exposures/interventions, comparators, outcomes, measured variables, confounding variables), the statistics, and the certainty of this evidence.

**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="Evidence.url"></a>

## Evidence.url
Canonical identifier for this evidence, represented as a globally unique URI

**Definition:** An absolute URI that is used to identify this evidence 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 summary is (or will be) published. This URL can be the target of a canonical reference. It SHALL remain the same when the summary 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 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="Evidence.identifier"></a>

## Evidence.identifier
Additional identifier for the summary

**Definition:** A formal identifier that is used to identify this summary 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="Evidence.version"></a>

## Evidence.version
Business version of this summary

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

**Cardinality:** 0..1

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

**Summary:** true

**Mappings:** w5=FiveWs.version


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

## Evidence.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="Evidence.name"></a>

## Evidence.name
Name for this summary (machine friendly)

**Definition:** A natural language name identifying the evidence. 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.

**Conditions:** cnl-0

**Cardinality:** 0..1

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


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

## Evidence.title
Name for this summary (human friendly)

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

**Cardinality:** 0..1

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

**Summary:** true


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

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

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

**Cardinality:** 0..1

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


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

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

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

**Comments:** Allows filtering of summaries 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 Evidence without due consideration)

**Mappings:** w5=FiveWs.status


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

## Evidence.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="Evidence.date"></a>

## Evidence.date
Date last changed

**Definition:** The date  (and optionally time) when the summary 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 summary 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 summary. 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="Evidence.approvalDate"></a>

## Evidence.approvalDate
When the summary 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.

**Comments:** The 'date' element may be more recent than the approval date because of minor changes or editorial corrections.

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

**Cardinality:** 0..1

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

**Mappings:** objimpl=no-gen-base


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

## Evidence.lastReviewDate
When the summary 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).

**Requirements:** Gives a sense of how "current" the content is.  Resources that have not been reviewed in a long time may have a risk of being less appropriate/relevant.

**Cardinality:** 0..1

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

**Mappings:** objimpl=no-gen-base


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

## Evidence.author
Who authored the content

**Definition:** An individiual, organization, or device 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)

**Summary:** true

**Mappings:** w5=FiveWs.author


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

## Evidence.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.

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

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

**Cardinality:** 0..1

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

**Summary:** true

**Mappings:** w5=FiveWs.witness


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

## Evidence.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="Evidence.recorder"></a>

## Evidence.recorder
Who entered the data for the evidence

**Definition:** Who entered the data for the evidence.

**Comments:** The Evidence.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 Evidence Resource.

**Cardinality:** 0..*

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


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

## Evidence.editor
Who edited the content

**Definition:** An individiual, organization, or device 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="Evidence.reviewer"></a>

## Evidence.reviewer
Who reviewed the content

**Definition:** An individiual, organization, or device 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)


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

## Evidence.endorser
Who endorsed the content

**Definition:** An individiual, organization, or device 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)


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

## Evidence.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 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="Evidence.purpose"></a>

## Evidence.purpose
Why this Evidence is defined

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

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

**Cardinality:** 0..1

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

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


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

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

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

**Comments:** The short copyright declaration (e.g. (c) '2015+ xyz organization') should be sent in the copyrightLabel element without the copyright prefix (i.e., do not include '(c)' or the symbol).

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

**Aliases:** License, Restrictions

**Cardinality:** 0..1

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

**Mappings:** objimpl=no-gen-base


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

## Evidence.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="Evidence.relatesTo"></a>

## Evidence.relatesTo
Relationships to other Resources

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

**Cardinality:** 0..*

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


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

## Evidence.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="Evidence.relatesTo.target[x]"></a>

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

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

**Cardinality:** 1..1

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


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

## Evidence.description
Description of the particular summary

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

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

**Cardinality:** 0..1

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

**Summary:** true


<a id="Evidence.assertion"></a>

## Evidence.assertion
Declarative description of the Evidence

**Definition:** Declarative description of the Evidence, such as conclusion or bottom line statement.

**Cardinality:** 0..1

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


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

## Evidence.note
Footnotes and/or explanatory notes

**Definition:** Footnotes and/or explanatory notes.

**Cardinality:** 0..*

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


<a id="Evidence.variableDefinition"></a>

## Evidence.variableDefinition
Description, classification, and definition of a single variable

**Definition:** Description, classification, and definition of a single variable. The collection of variables defines what the evidence is about.

**Comments:** Comparative evidence is often defined with a population variable, an exposure variable and an outcome variable, while non comparative evidence is often defined with a population variable and an outcome variable.

**Cardinality:** 0..*

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


<a id="Evidence.variableDefinition.description"></a>

## Evidence.variableDefinition.description
A text description or summary of the variable

**Definition:** A text description or summary of the variable.

**Cardinality:** 0..1

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


<a id="Evidence.variableDefinition.note"></a>

## Evidence.variableDefinition.note
Footnotes and/or explanatory notes

**Definition:** Footnotes and/or explanatory notes.

**Cardinality:** 0..*

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


<a id="Evidence.variableDefinition.variableRole"></a>

## Evidence.variableDefinition.variableRole
population | exposure | outcome | covariate

**Definition:** Classification of the role of the variable.

**Cardinality:** 1..1

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

**Binding:** required:[variable-role](/valueset-variable-role)

**Summary:** true


<a id="Evidence.variableDefinition.roleSubtype"></a>

## Evidence.variableDefinition.roleSubtype
Sub-classification of the role of the variable

**Definition:** Sub-classification of the role of the variable.

**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-role-subtype](/valueset-variable-role-subtype)


<a id="Evidence.variableDefinition.comparatorCategory"></a>

## Evidence.variableDefinition.comparatorCategory
The reference value used for comparison

**Definition:** The reference value used for comparison.

**Comments:** Value should match EvidenceVariable.category.name in the EvidenceVariable referenced in the observed or intended element.

**Cardinality:** 0..1

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


<a id="Evidence.variableDefinition.observed"></a>

## Evidence.variableDefinition.observed
Definition of the actual variable related to the statistic(s)

**Definition:** Definition of the actual variable related to the statistic(s), i.e., the population being the actual study sample or the measured variable (exposure, outcome, or covariate) being the actual observation that occurred or will occur in the study.

**Cardinality:** 0..1

**Type:** Reference([Group](/Group), [EvidenceVariable](/EvidenceVariable))

**Summary:** true


<a id="Evidence.variableDefinition.intended"></a>

## Evidence.variableDefinition.intended
Definition of the intended variable related to the Evidence

**Definition:** Definition of the intended variable related to the Evidence, i.e., the population, exposure, or outcome for which the statistical finding is being interpreted.

**Cardinality:** 0..1

**Type:** Reference([Group](/Group), [EvidenceVariable](/EvidenceVariable))


<a id="Evidence.variableDefinition.directnessMatch"></a>

## Evidence.variableDefinition.directnessMatch
low | moderate | high | exact

**Definition:** Indication of quality of match between intended variable to actual variable.

**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:[directness](/valueset-directness)


<a id="Evidence.synthesisType"></a>

## Evidence.synthesisType
The design of the synthesis (combination of studies) that produced this evidence

**Definition:** The design of the synthesis (combination of studies) that produced this evidence. The design is described with any number of synthesis characteristics, such as type of meta-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..*

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

**Binding:** example:[synthesis-type](/valueset-synthesis-type)


<a id="Evidence.studyDesign"></a>

## Evidence.studyDesign
The design of the study that produced this evidence

**Definition:** The design of the study that produced this evidence. The design is described with any number of study design characteristics.

**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..*

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

**Binding:** extensible:[study-design](/valueset-study-design)


<a id="Evidence.statistic"></a>

## Evidence.statistic
Values and parameters for a single statistic

**Definition:** Values and parameters for a single statistic.

**Cardinality:** 0..*

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


<a id="Evidence.statistic.description"></a>

## Evidence.statistic.description
A natural language summary of the statistic

**Cardinality:** 0..1

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


<a id="Evidence.statistic.note"></a>

## Evidence.statistic.note
Footnotes and/or explanatory notes

**Cardinality:** 0..*

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


<a id="Evidence.statistic.statisticType"></a>

## Evidence.statistic.statisticType
Type of statistic, e.g., relative risk

**Definition:** Type of statistic, e.g., relative risk. The statistic type is a classification that formally defines the relationship between the variables (noted in Evidence.variableDefinition) and the value specification (noted in Evidence.statistic.quantity).

**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:[statistic-type](/valueset-statistic-type)

**Summary:** true


<a id="Evidence.statistic.category"></a>

## Evidence.statistic.category
Associated category for categorical variable

**Definition:** When the measured variable (outcome) is handled categorically, the category element is used to define which category the statistic is reporting.

**Comments:** Simple strings can be used for descriptive purposes. Exact matching to EvidenceVariable.category.name for the Evidence.variableDefinition[variableRole=outcome].observed=Reference(EvidenceVariable) could facilitate validation within datasets.

**Cardinality:** 0..1

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


<a id="Evidence.statistic.quantity"></a>

## Evidence.statistic.quantity
Statistic value

**Cardinality:** 0..1

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

**Summary:** true


<a id="Evidence.statistic.numberOfEvents"></a>

## Evidence.statistic.numberOfEvents
The number of events associated with the statistic

**Definition:** The number of events associated with the statistic, where the unit of analysis is different from numberAffected, sampleSize.knownDataCount and sampleSize.numberOfParticipants.

**Comments:** When the number of events is the statistic, use Evidence.statistic.quantity and set Evidence.statistic.type.coding.code=C25463 and Evidence.statistic.type.coding.display=Count. When the statistic is an Event Rate (where individual participants may have 2 or more events), use Evidence.statistic.numberOfEvents to record the total number of events rather than the number of participants with events.

**Cardinality:** 0..1

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


<a id="Evidence.statistic.numberAffected"></a>

## Evidence.statistic.numberAffected
The number of participants affected

**Definition:** The number of participants affected where the unit of analysis is the same as sampleSize.knownDataCount and sampleSize.numberOfParticipants.

**Comments:** When the number affected is the statistic, use Evidence.statistic.quantity and set Evidence.statistic.type.coding.code=C25463 and Evidence.statistic.type.coding.display=Count. When the statistic is a Proportion, use Evidence.statistic.numberAffected and enter an integer as the value. When the statistic is an Event Rate (where individual participants may have 2 or more events), use Evidence.statistic.numberAffected to record the number of participants with events rather than the total number of events.

**Cardinality:** 0..1

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


<a id="Evidence.statistic.sampleSize"></a>

## Evidence.statistic.sampleSize
Count of participants in the study sample

**Cardinality:** 0..1

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


<a id="Evidence.statistic.sampleSize.description"></a>

## Evidence.statistic.sampleSize.description
Textual description of sample size for statistic

**Definition:** Human-readable summary of study sample size. A human-readable string to clarify or explain concepts about the sample size.

**Cardinality:** 0..1

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


<a id="Evidence.statistic.sampleSize.note"></a>

## Evidence.statistic.sampleSize.note
Footnote or explanatory note about the sample size

**Cardinality:** 0..*

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


<a id="Evidence.statistic.sampleSize.numberOfStudies"></a>

## Evidence.statistic.sampleSize.numberOfStudies
Number of contributing studies

**Definition:** Count of studies or samples combined to become the total sample for the statistic.

**Cardinality:** 0..1

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


<a id="Evidence.statistic.sampleSize.numberOfParticipants"></a>

## Evidence.statistic.sampleSize.numberOfParticipants
Total number of participants

**Definition:** Count of members in the total sample for the statistic.

**Cardinality:** 0..1

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


<a id="Evidence.statistic.sampleSize.knownDataCount"></a>

## Evidence.statistic.sampleSize.knownDataCount
Number of participants with known results for measured variables

**Cardinality:** 0..1

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


<a id="Evidence.statistic.sampleSize.numberAnalyzed"></a>

## Evidence.statistic.sampleSize.numberAnalyzed
Total number of participants who were analayzed

**Cardinality:** 0..1

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


<a id="Evidence.statistic.attributeEstimate"></a>

## Evidence.statistic.attributeEstimate
An attribute of the Statistic

**Definition:** A statistical attribute of the statistic such as a measure of heterogeneity.

**Cardinality:** 0..*

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


<a id="Evidence.statistic.attributeEstimate.description"></a>

## Evidence.statistic.attributeEstimate.description
Textual description of the attribute estimate

**Definition:** Human-readable summary of the estimate.

**Cardinality:** 0..1

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


<a id="Evidence.statistic.attributeEstimate.note"></a>

## Evidence.statistic.attributeEstimate.note
Footnote or explanatory note about the estimate

**Cardinality:** 0..*

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


<a id="Evidence.statistic.attributeEstimate.type"></a>

## Evidence.statistic.attributeEstimate.type
The type of attribute estimate, e.g., confidence interval or p value

**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:[attribute-estimate-type](/valueset-attribute-estimate-type)


<a id="Evidence.statistic.attributeEstimate.quantity"></a>

## Evidence.statistic.attributeEstimate.quantity
The singular quantity of the attribute estimate, for attribute estimates represented as single values, which may include a unit of measure

**Comments:** Often the p value

**Cardinality:** 0..1

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


<a id="Evidence.statistic.attributeEstimate.level"></a>

## Evidence.statistic.attributeEstimate.level
Level of confidence interval, e.g., 0.95 for 95% confidence interval

**Definition:** Use 0.95 for a 95% confidence interval.

**Cardinality:** 0..1

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


<a id="Evidence.statistic.attributeEstimate.range"></a>

## Evidence.statistic.attributeEstimate.range
Lower and upper bound values of the attribute estimate

**Cardinality:** 0..1

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


<a id="Evidence.statistic.attributeEstimate.attributeEstimate"></a>

## Evidence.statistic.attributeEstimate.attributeEstimate
A nested attribute estimate; which is the attribute estimate of an attribute estimate

**Definition:** A nested attribute estimate; which is the attribute estimate of an attribute estimate.

**Comments:** A nested attribute estimate; which is the attribute estimate of an attribute estimate

**Cardinality:** 0..*


<a id="Evidence.statistic.modelCharacteristic"></a>

## Evidence.statistic.modelCharacteristic
An aspect of the statistical model

**Definition:** A component of the method to generate the statistic.

**Cardinality:** 0..*

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


<a id="Evidence.statistic.modelCharacteristic.code"></a>

## Evidence.statistic.modelCharacteristic.code
Model specification

**Definition:** Description of a component of the method to generate the statistic.

**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:** 1..1

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

**Binding:** example:[statistic-model-code](/valueset-statistic-model-code)


<a id="Evidence.statistic.modelCharacteristic.value[x]"></a>

## Evidence.statistic.modelCharacteristic.value[x]
The specific value (when paired with code)

**Definition:** Further specification of the value of the component of the method to generate the statistic.

**Cardinality:** 0..1

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


<a id="Evidence.statistic.modelCharacteristic.intended"></a>

## Evidence.statistic.modelCharacteristic.intended
The plan for analysis

**Cardinality:** 0..1

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


<a id="Evidence.statistic.modelCharacteristic.applied"></a>

## Evidence.statistic.modelCharacteristic.applied
This model characteristic is part of the analysis that was applied, whether or not the analysis followed the plan

**Meaning if Missing:** True, unless modelCharacteristic.intended = true; if modelCharacteristic.intended = true and .applied is missing, then meaning Unknown.

**Cardinality:** 0..1

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


<a id="Evidence.statistic.modelCharacteristic.variable"></a>

## Evidence.statistic.modelCharacteristic.variable
A variable adjusted for in the adjusted analysis

**Cardinality:** 0..*

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


<a id="Evidence.statistic.modelCharacteristic.variable.variableDefinition"></a>

## Evidence.statistic.modelCharacteristic.variable.variableDefinition
Description and definition of the variable

**Cardinality:** 1..1

**Type:** Reference([Group](/Group), [EvidenceVariable](/EvidenceVariable))


<a id="Evidence.statistic.modelCharacteristic.variable.handling"></a>

## Evidence.statistic.modelCharacteristic.variable.handling
boolean | continuous | dichotomous | ordinal | polychotomous | time-to-event | not-specified

**Definition:** How the variable is classified for use in adjusted 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="Evidence.statistic.modelCharacteristic.variable.valueCategory"></a>

## Evidence.statistic.modelCharacteristic.variable.valueCategory
Qualitative label used for grouping values of a dichotomous, ordinal, or polychotomous variable

**Cardinality:** 0..*

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


<a id="Evidence.statistic.modelCharacteristic.variable.valueQuantity"></a>

## Evidence.statistic.modelCharacteristic.variable.valueQuantity
Quantitative label used for grouping values of a dichotomous, ordinal, or polychotomous variable

**Cardinality:** 0..*

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


<a id="Evidence.statistic.modelCharacteristic.variable.valueRange"></a>

## Evidence.statistic.modelCharacteristic.variable.valueRange
Range of quantitative labels used for grouping values of a dichotomous, ordinal, or polychotomous variable

**Cardinality:** 0..*

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


<a id="Evidence.statistic.modelCharacteristic.attribute"></a>

## Evidence.statistic.modelCharacteristic.attribute
An attribute of the model characteristic

**Cardinality:** 0..*


<a id="Evidence.certainty"></a>

## Evidence.certainty
Certainty or quality of the evidence

**Definition:** Assessment of certainty, confidence in the estimates, or quality of the evidence.

**Cardinality:** 0..*

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


<a id="Evidence.certainty.description"></a>

## Evidence.certainty.description
Textual description of certainty

**Definition:** Textual description of certainty.

**Cardinality:** 0..1

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


<a id="Evidence.certainty.note"></a>

## Evidence.certainty.note
Footnotes and/or explanatory notes

**Definition:** Footnotes and/or explanatory notes.

**Cardinality:** 0..*

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


<a id="Evidence.certainty.type"></a>

## Evidence.certainty.type
Aspect of certainty being rated

**Definition:** Aspect of certainty being rated.

**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:[certainty-type](/valueset-certainty-type)


<a id="Evidence.certainty.rating"></a>

## Evidence.certainty.rating
Assessment or judgement of the aspect

**Definition:** Assessment or judgement of the aspect.

**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:[certainty-rating](/valueset-certainty-rating)


<a id="Evidence.certainty.rater"></a>

## Evidence.certainty.rater
Individual or group who did the rating

**Definition:** Individual or group who did the rating.

**Cardinality:** 0..*

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


<a id="Evidence.certainty.subcomponent"></a>

## Evidence.certainty.subcomponent
A domain or subdomain of certainty

**Definition:** A domain or subdomain of certainty.

**Cardinality:** 0..*