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

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).

A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content. Often, this is a reference to an implementation guide that defines the special rules along with other profiles etc.

Asserting this rule set restricts the content to be only understood by a limited set of trading partners. This inherently limits the usefulness of the data in the long term. However, the existing health eco-system is highly fractured, and not yet ready to define, collect, and exchange data in a generally computable sense. Wherever possible, implementers and/or specification writers should avoid using this element. Often, when used, the URL is a reference to an implementation guide that defines these special rules as part of its narrative along with other profiles, value sets, etc.

These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, nor can they have their own independent transaction scope. This is allowed to be a Parameters resource if and only if it is referenced by a resource that provides context/meaning.

This should never be done when the content can be identified properly, as once identification is lost, it is extremely difficult (and context dependent) to restore it again. Contained resources may have profiles and tags in their meta elements, but SHALL NOT have security labels.

An Extension

• value @ url

Defines the variable with a concept and/or Reference.

An Extension

• value @ url

Source of the definition for the extension code - a logical name or a URL.

The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.

May be used to represent additional information that is not part of the basic definition of the resource and that modifies the understanding of the element that contains it and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

The status of this evidence variable. Enables tracking the life-cycle of the content.

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

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

The lifecycle status of an artifact.

A defining factor of the EvidenceVariable. Multiple characteristics are applied with "and" semantics.

Characteristics can be defined flexibly to accommodate different use cases for membership criteria, ranging from simple codes, all the way to using an expression language to express the criteria.

The method of handling in statistical analysis.

A grouping for ordinal or polychotomous variables.

Defines the categorical value with a Reference.

May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

Description of the grouping.

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

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).

The logical id of the resource, as used in the URL for the resource. Once assigned, this value never changes.

Within the context of the FHIR RESTful interactions, the resource has an id except for cases like the create and conditional update. Otherwise, the use of the resouce id depends on the given use case.

The metadata about the resource. This is content that is maintained by the infrastructure. Changes to the content might not always be associated with version changes to the resource.

A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content. Often, this is a reference to an implementation guide that defines the special rules along with other profiles etc.

Asserting this rule set restricts the content to be only understood by a limited set of trading partners. This inherently limits the usefulness of the data in the long term. However, the existing health eco-system is highly fractured, and not yet ready to define, collect, and exchange data in a generally computable sense. Wherever possible, implementers and/or specification writers should avoid using this element. Often, when used, the URL is a reference to an implementation guide that defines these special rules as part of its narrative along with other profiles, value sets, etc.

The base language in which the resource is written.

Language is provided to support indexing and accessibility (typically, services such as text to speech use the language tag). The html language tag in the narrative applies to the narrative. The language tag on the resource may be used to specify the language of other presentations generated from the data in the resource. Not all the content has to be in the base language. The Resource.language should not be assumed to apply to the narrative automatically. If a language is specified, it should it also be specified on the div element in the html (see rules in HTML5 for information about the relationship between xml:lang and the html lang attribute).

IETF language tag for a human language

A human-readable narrative that contains a summary of the resource and can be used to represent the content of the resource to a human. The narrative need not encode all the structured data, but is required to contain sufficient detail to make it "clinically safe" for a human to just read the narrative. Resource definitions may define what content should be represented in the narrative to ensure clinical safety.

Contained resources do not have a narrative. Resources that are not contained SHOULD have a narrative. In some cases, a resource may only have text with little or no additional discrete data (as long as all minOccurs=1 elements are satisfied). This may be necessary for data from legacy systems where information is captured as a "text blob" or where text is additionally entered raw or narrated and encoded information is added later.

These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, nor can they have their own independent transaction scope. This is allowed to be a Parameters resource if and only if it is referenced by a resource that provides context/meaning.

This should never be done when the content can be identified properly, as once identification is lost, it is extremely difficult (and context dependent) to restore it again. Contained resources may have profiles and tags in their meta elements, but SHALL NOT have security labels.

An Extension

• value @ url

Defines the variable with a concept and/or Reference.

Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

An Extension

• value @ url

Source of the definition for the extension code - a logical name or a URL.

The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.

Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

• value @ url

A reference to a concept - e.g. the information is identified by its general class to the degree of precision found in the terminology.

Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

• value @ url

A reference to a code defined by a terminology system.

Codes may be defined very casually in enumerations, or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information. Ordering of codings is undefined and SHALL NOT be used to infer meaning. Generally, at most only one of the coding values will be labeled as UserSelected = true.

Allows for alternative encodings within a code system, and translations to other code systems.

A human language representation of the concept as seen/selected/uttered by the user who entered the data and/or which represents the intended meaning of the user.

Very often the text is the same as a displayName of one of the codings.

The codes from the terminologies do not always capture the correct meaning with all the nuances of the human using them, or sometimes there is no appropriate code at all. In these cases, the text is used to capture the full meaning of the source.

A reference to a resource the provides exact details about the information being referenced.

May be used to represent additional information that is not part of the basic definition of the resource and that modifies the understanding of the element that contains it and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

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.

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.

Allows the evidence variable to be referenced by a single globally unique identifier.

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.

Typically, this is used for identifiers that can go in an HL7 V3 II (instance identifier) data type, and can then identify this evidence variable outside of FHIR, where it is not possible to use the logical URI.

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

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.

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.

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

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.

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.

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.

Support human navigation and code generation.

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

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

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

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

The status of this evidence variable. Enables tracking the life-cycle of the content.

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

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

The lifecycle status of an artifact.

A Boolean value to indicate that this resource is authored for testing purposes (or education/evaluation/marketing) and is not intended to be used for genuine usage.

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.

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.

The name of the organization or individual responsible for the release and ongoing maintenance of the evidence variable.

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.

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

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

Extensions to ContactDetail include: contactReference, contactAddress, and contributionTime (see Clinical Reasoning Module).

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

A free text natural language description of the evidence variable from a consumer's perspective.

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).

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

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.

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

Assist in searching for appropriate content.

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

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.

A copyright statement relating to the resource and/or its contents. Copyright statements are generally legal restrictions on the use and publishing of the resource.

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

The (c) symbol 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.

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

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.

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

If specified, this date follows the original approval date.

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

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

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.

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

Extensions to ContactDetail include: contactReference, contactAddress, and contributionTime (see Clinical Reasoning Module).

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

Extensions to ContactDetail include: contactReference, contactAddress, and contributionTime (see Clinical Reasoning Module).

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

Extensions to ContactDetail include: contactReference, contactAddress, and contributionTime (see Clinical Reasoning Module).

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

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

Extensions to ContactDetail include: contactReference, contactAddress, and contributionTime (see Clinical Reasoning Module).

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

Related artifacts such as additional documentation, justification, or bibliographic references.

Each related artifact is either an attachment, or a reference to another resource, but not both.

EvidenceVariables must be able to provide enough information for consumers of the content (and/or interventions or results produced by the content) to be able to determine and understand the justification for and evidence in support of the content.

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

A defining factor of the EvidenceVariable. Multiple characteristics are applied with "and" semantics.

Characteristics can be defined flexibly to accommodate different use cases for membership criteria, ranging from simple codes, all the way to using an expression language to express the criteria.

The method of handling in statistical analysis.

A grouping for ordinal or polychotomous variables.

Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

An Extension

• value @ url

Defines the categorical value with a Reference.

May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

Description of the grouping.

Definition of the grouping.