The EvidenceVariable resource describes a "PICO" an element that knowledge (evidence, assertion, recommendation) (Evidence) is about.

Need to be able to define and reuse the definition of individual elements of a research question.

PICO stands for Population (the population within which exposures are being compared), Intervention (the conditional state or The EvidenceVariable may be an exposure state being described for its effect on outcomes), Comparison (the alternative conditional state variable (intervention, condition, or alternative exposure state being compared against), and Outcome (the result state), a measured variable (outcome or effect of the intervention in the population). observed parameter), or other variable (such as confounding factor).

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 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.

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

Can be a urn:uuid: or a urn:oid: but real http: addresses are preferred. Multiple instances may share the same URL if they have a distinct version.

The determination of when to create a new version of a resource (same url, new version) vs. defining a new artifact is up to the author. Considerations for making this decision are found in Technical and Business Versions .

In some cases, the resource can no longer be found at the stated url, but the url itself cannot change. Implementations can use the meta.source element to indicate where the current master source of the resource can be found.

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.

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

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.

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].

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.

Support human navigation and 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.

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.

An explanatory or alternate title for the EvidenceVariable giving additional information about its 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.

The date (and optionally time) when the evidence variable was published. 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.

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.

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 why the evidence variable was built, 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.

Assist in searching for appropriate content.

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

A legal The name of the organization or geographic region in which individual that published the evidence variable is intended to be used. variable.

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

It Usually an organization but may be possible for an individual. The publisher (or steward) of the evidence variable to be used in jurisdictions other than those for which it was originally designed is the organization or intended. To Do Note: individual primarily responsible for the maintenance and upkeep of the evidence variable. This was added back in because this is a metadata resource not necessarily the same individual or organization that developed and it's a required element initially authored the content. The publisher is the primary point of contact for metadata resource searching. questions or issues with the evidence variable. This item SHOULD be populated unless the information is available from context.

A copyright statement relating Contact details to the evidence variable and/or its contents. Copyright statements are generally legal restrictions on the use assist a user in finding and publishing of communicating with the evidence variable. publisher.

Extensions to ContactDetail include: contactReference, contactAddress, and contributionTime (Details at: http://build.fhir.org/clinicalreasoning-module.html).

The date on which the resource content was approved by An individiual or organization primarily involved in the publisher. Approval happens once when creation and maintenance of the content is officially approved for usage. content.

Extensions to this resource. ContactDetail include: contactReference, contactAddress, and contributionTime (Details at: http://build.fhir.org/clinicalreasoning-module.html).

The date on which the resource content was last reviewed. Review happens periodically after approval but does not change An individual or organization primarily responsible for internal coherence of the original approval date. content.

If specified, this date follows the original approval date. To Do Consider how this applies Extensions to this resource. ContactDetail include: contactReference, contactAddress, and contributionTime (Details at: http://build.fhir.org/clinicalreasoning-module.html).

The period during which the evidence variable content was An individual or is planned to be in active use. organization primarily responsible for review of some aspect of the content.

The effective period for a evidence variable determines when the content is applicable for usage and is independent of publication and review dates. For example, a measure intended Extensions to be used for the year 2016 might be published in 2015. ContactDetail include: contactReference, contactAddress, and contributionTime (Details at: http://build.fhir.org/clinicalreasoning-module.html).

Descriptive topics related to An individual or organization responsible for officially endorsing the content of the EvidenceVariable. Topics provide a high-level categorization grouping types of EvidenceVariables that can be useful for filtering and searching. use in some setting.

Repositories must be able to determine how Extensions to categorize the EvidenceVariable so that it can be found by topical searches. ContactDetail include: contactReference, contactAddress, and contributionTime (Details at: http://build.fhir.org/clinicalreasoning-module.html).

An individiual Related artifacts such as additional documentation, justification, or organization primarily involved in the creation and maintenance of the content. bibliographic references.

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

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

An individual or organization primarily responsible for review of some aspect True if the actual variable measured, false if a conceptual representation of the content. intended variable.

An individual Used to specify how two or organization responsible for officially endorsing the content for use in some setting. more characteristics are combined.

Related artifacts such as additional documentation, justification, Used to specify if two or bibliographic references. more characteristics are combined with OR or AND.

Each related artifact If code is either an attachment, "at-least" or a reference to another resource, but not both. "at-most" then threshold SHALL be used. If code is neither "at-least" nor "at-most" then threshold SHALL NOT be used.

The type Provides the value of evidence element, a population, an exposure, "n" when "at-least" or an outcome. "at-most" codes are used.

A characteristic that defines the members of the evidence element. 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.

A short, natural language description of the characteristic that could be used to communicate the criteria to an end-user.

Need to be able to describe characteristics in natural language so that end users can understand the criteria.

Used to expressing the type of characteristic.

Define members of the evidence element using Codes (such as condition, medication, or observation), Expressions ( using an expression language such as FHIRPath or CQL) or DataRequirements (such as Diabetes diagnosis onset in the last year).

Need to be able to define members in simple codes when the membership aligns well with terminology, with common criteria such as observations in a value set or lab tests within a year, or with expression language to support criteria that do not fit in the above.

Use UsageContext to define the members of the population, such as Age Ranges, Genders, Settings. Method used for describing characteristic.

Need to be able to define members more structurally when more information can be communicated such as age range. Device used for determining characteristic.

When true, members with this characteristic are excluded from the element.

Indicates what effective period the Observation time from study covers. specified event.

Human readable description.

The event used as a base point (reference point) in time.

Used to use [x] express the observation at a defined amount of time after the study start.

Indicates duration from Used to express the observation within a period after the participant's study entry. start.

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

Indicates how elements are aggregated within Value or set of values that define the study effective period. grouping.

continuous | dichotomous | ordinal | polychotomous.

A grouping for ordinal or polychotomous variables.

Description of the grouping.

Definition of the grouping.