StructureDefinition: PICOElement - XML

PICOElement

<?xml version="1.0" encoding="UTF-8"?>

<StructureDefinition xmlns="http://hl7.org/fhir">
  <id value="picoelement"/> 
  <text> 
    <status value="generated"/> 
    <div xmlns="http://www.w3.org/1999/xhtml">to do</div> 
  </text> 
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm">
    <valueInteger value="0"/> 
  </extension> 
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-wg">
    <valueCode value="cds"/> 
  </extension> 
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status">
    <valueCode value="trial-use"/> 
  </extension> 
  <url value="http://hl7.org/fhir/StructureDefinition/picoelement"/> 
  <version value="4.0.1"/> 
  <name value="PICO Element Profile"/> 
  <status value="draft"/> 
  <experimental value="false"/> 
  <date value="2018-10-31"/> 
  <publisher value="Health Level Seven, Inc. - Clinical Decision Support Workgroup"/> 
  <contact> 
    <telecom> 
      <system value="url"/> 
      <value value="http://www.hl7.org/Special/committees/dss/index.cfm"/> 
    </telecom> 
  </contact> 
  <description value="Explanation of what this profile contains/is for."/> 
  <purpose value="Need to be able to define and reuse the definition of individual elements of a research
   question."/> 
  <fhirVersion value="4.0.1"/> 
  <mapping> 
    <identity value="workflow"/> 
    <uri value="http://hl7.org/fhir/workflow"/> 
    <name value="Workflow Pattern"/> 
  </mapping> 
  <mapping> 
    <identity value="objimpl"/> 
    <uri value="http://hl7.org/fhir/object-implementation"/> 
    <name value="Object Implementation Information"/> 
  </mapping> 
  <mapping> 
    <identity value="w5"/> 
    <uri value="http://hl7.org/fhir/fivews"/> 
    <name value="FiveWs Pattern Mapping"/> 
  </mapping> 
  <mapping> 
    <identity value="rim"/> 
    <uri value="http://hl7.org/v3"/> 
    <name value="RIM Mapping"/> 
  </mapping> 
  <kind value="resource"/> 
  <abstract value="false"/> 
  <type value="EvidenceVariable"/> 
  <baseDefinition value="http://hl7.org/fhir/StructureDefinition/EvidenceVariable"/> 
  <derivation value="constraint"/> 
  <snapshot> 
    <element id="EvidenceVariable">
      <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-display-hint">
        <valueString value="0;0"/> 
      </extension> 
      <path value="EvidenceVariable"/> 
      <short value="A population, intervention, or exposure definition"/> 
      <definition value="The EvidenceVariable resource describes a &quot;PICO&quot; element that knowledge (evidence,
       assertion, recommendation) is about."/> 
      <comment value="PICO stands for Population (the population within which exposures are being compared),
       Intervention (the conditional state or exposure state being described for its effect on
       outcomes), Comparison (the alternative conditional state or alternative exposure state
       being compared against), and Outcome (the result or effect of the intervention in the
       population)."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="EvidenceVariable"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <constraint> 
        <key value="dom-2"/> 
        <severity value="error"/> 
        <human value="If the resource is contained in another resource, it SHALL NOT contain nested Resources"/> 
        <expression value="contained.contained.empty()"/> 
        <xpath value="not(parent::f:contained and f:contained)"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/DomainResource"/> 
      </constraint> 
      <constraint> 
        <key value="dom-3"/> 
        <severity value="error"/> 
        <human value="If the resource is contained in another resource, it SHALL be referred to from elsewhere
         in the resource or SHALL refer to the containing resource"/> 
        <expression value="contained.where((('#'+id in (%resource.descendants().reference | %resource.descendants().as(canonica
        l) | %resource.descendants().as(uri) | %resource.descendants().as(url))) or descendants().where(refer
        ence = '#').exists() or descendants().where(as(canonical) = '#').exists() or descendants().where(as(c
        anonical) = '#').exists()).not()).trace('unmatched', id).empty()"/> 
        <xpath value="not(exists(for $id in f:contained/*/f:id/@value return $contained[not(parent::*/descendant::f:refere
        nce/@value=concat('#', $contained/*/id/@value) or descendant::f:reference[@value='#'])]))"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/DomainResource"/> 
      </constraint> 
      <constraint> 
        <key value="dom-4"/> 
        <severity value="error"/> 
        <human value="If a resource is contained in another resource, it SHALL NOT have a meta.versionId or
         a meta.lastUpdated"/> 
        <expression value="contained.meta.versionId.empty() and contained.meta.lastUpdated.empty()"/> 
        <xpath value="not(exists(f:contained/*/f:meta/f:versionId)) and not(exists(f:contained/*/f:meta/f:lastUpdated))"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/DomainResource"/> 
      </constraint> 
      <constraint> 
        <key value="dom-5"/> 
        <severity value="error"/> 
        <human value="If a resource is contained in another resource, it SHALL NOT have a security label"/> 
        <expression value="contained.meta.security.empty()"/> 
        <xpath value="not(exists(f:contained/*/f:meta/f:security))"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/DomainResource"/> 
      </constraint> 
      <constraint> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bestpractice">
          <valueBoolean value="true"/> 
        </extension> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bestpractice-explanation">
          <valueMarkdown value="When a resource has no narrative, only systems that fully understand the data can display
           the resource to a human safely. Including a human readable representation in the resource
           makes for a much more robust eco-system and cheaper handling of resources by intermediary
           systems. Some ecosystems restrict distribution of resources to only those systems that
           do fully understand the resources, and as a consequence implementers may believe that
           the narrative is superfluous. However experience shows that such eco-systems often open
           up to new participants over time."/> 
        </extension> 
        <key value="dom-6"/> 
        <severity value="warning"/> 
        <human value="A resource should have narrative for robust management"/> 
        <expression value="text.`div`.exists()"/> 
        <xpath value="exists(f:text/h:div)"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/DomainResource"/> 
      </constraint> 
      <constraint> 
        <key value="evv-0"/> 
        <severity value="warning"/> 
        <human value="Name should be usable as an identifier for the module by machine processing applications
         such as code generation"/> 
        <expression value="name.matches('[A-Z]([A-Za-z0-9_]){0,254}')"/> 
        <xpath value="not(exists(f:name/@value)) or matches(f:name/@value, '[A-Z]([A-Za-z0-9_]){0,254}')"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/EvidenceVariable"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="Entity. Role, or Act"/> 
      </mapping> 
      <mapping> 
        <identity value="workflow"/> 
        <map value="Definition"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.id">
      <path value="EvidenceVariable.id"/> 
      <short value="Logical id of this artifact"/> 
      <definition value="The logical id of the resource, as used in the URL for the resource. Once assigned, this
       value never changes."/> 
      <comment value="The only time that a resource does not have an id is when it is being submitted to the
       server using a create operation."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Resource.id"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
          <valueUrl value="string"/> 
        </extension> 
        <code value="http://hl7.org/fhirpath/System.String"/> 
      </type> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="EvidenceVariable.meta">
      <path value="EvidenceVariable.meta"/> 
      <short value="Metadata about the resource"/> 
      <definition value="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."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Resource.meta"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="Meta"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="EvidenceVariable.implicitRules">
      <path value="EvidenceVariable.implicitRules"/> 
      <short value="A set of rules under which this content was created"/> 
      <definition value="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."/> 
      <comment value="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
       it's narrative along with other profiles, value sets, etc."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Resource.implicitRules"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="uri"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="true"/> 
      <isModifierReason value="This element is labeled as a modifier because the implicit rules may provide additional
       knowledge about the resource that modifies it's meaning or interpretation"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="EvidenceVariable.language">
      <path value="EvidenceVariable.language"/> 
      <short value="Language of the resource content"/> 
      <definition value="The base language in which the resource is written."/> 
      <comment value="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)."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Resource.language"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="code"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <binding> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-maxValueSet">
          <valueCanonical value="http://hl7.org/fhir/ValueSet/all-languages"/> 
        </extension> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="Language"/> 
        </extension> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-isCommonBinding">
          <valueBoolean value="true"/> 
        </extension> 
        <strength value="preferred"/> 
        <description value="A human language."/> 
        <valueSet value="http://hl7.org/fhir/ValueSet/languages"/> 
      </binding> 
    </element> 
    <element id="EvidenceVariable.text">
      <path value="EvidenceVariable.text"/> 
      <short value="Text summary of the resource, for human interpretation"/> 
      <definition value="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 &quot;clinically
       safe&quot; for a human to just read the narrative. Resource definitions may define what
       content should be represented in the narrative to ensure clinical safety."/> 
      <comment value="Contained resources do not have 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 &quot;text blob&quot;
       or where text is additionally entered raw or narrated and encoded information is added
       later."/> 
      <alias value="narrative"/> 
      <alias value="html"/> 
      <alias value="xhtml"/> 
      <alias value="display"/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="DomainResource.text"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="Narrative"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="Act.text?"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.contained">
      <path value="EvidenceVariable.contained"/> 
      <short value="Contained, inline Resources"/> 
      <definition value="These resources do not have an independent existence apart from the resource that contains
       them - they cannot be identified independently, and nor can they have their own independent
       transaction scope."/> 
      <comment value="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."/> 
      <alias value="inline resources"/> 
      <alias value="anonymous resources"/> 
      <alias value="contained resources"/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="DomainResource.contained"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="Resource"/> 
      </type> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.extension">
      <path value="EvidenceVariable.extension"/> 
      <short value="Additional content defined by implementations"/> 
      <definition value="May be used to represent additional information that is not part of the basic definition
       of the resource. To make the use of extensions safe and manageable, 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."/> 
      <comment value="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."/> 
      <alias value="extensions"/> 
      <alias value="user content"/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="DomainResource.extension"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="Extension"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <constraint> 
        <key value="ext-1"/> 
        <severity value="error"/> 
        <human value="Must have either extensions or value[x], not both"/> 
        <expression value="extension.exists() != value.exists()"/> 
        <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), &quot;value&quot;)])"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.modifierExtension">
      <path value="EvidenceVariable.modifierExtension"/> 
      <short value="Extensions that cannot be ignored"/> 
      <definition value="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 manageable, 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)."/> 
      <comment value="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."/> 
      <requirements value="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](http://hl7.org/f
      hir/extensibility.html#modifierExtension)."/> 
      <alias value="extensions"/> 
      <alias value="user content"/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="DomainResource.modifierExtension"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="Extension"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <constraint> 
        <key value="ext-1"/> 
        <severity value="error"/> 
        <human value="Must have either extensions or value[x], not both"/> 
        <expression value="extension.exists() != value.exists()"/> 
        <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), &quot;value&quot;)])"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/> 
      </constraint> 
      <isModifier value="true"/> 
      <isModifierReason value="Modifier extensions are expected to modify the meaning or interpretation of the resource
       that contains them"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.url">
      <path value="EvidenceVariable.url"/> 
      <short value="Canonical identifier for this evidence variable, represented as a URI (globally unique)"/> 
      <definition value="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."/> 
      <comment value="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](http://hl7.org/fhir/resource.html#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](http://hl7.org/fhir/resource.html#meta)
       element to indicate where the current master source of the resource can be found."/> 
      <requirements value="Allows the evidence variable to be referenced by a single globally unique identifier."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="EvidenceVariable.url"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="uri"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="workflow"/> 
        <map value="Definition.url"/> 
      </mapping> 
      <mapping> 
        <identity value="w5"/> 
        <map value="FiveWs.identifier"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.identifier">
      <path value="EvidenceVariable.identifier"/> 
      <short value="Additional identifier for the evidence variable"/> 
      <definition value="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."/> 
      <comment value="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."/> 
      <requirements value="Allows externally provided and/or usable business identifiers to be easily associated
       with the module."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="EvidenceVariable.identifier"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="Identifier"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="workflow"/> 
        <map value="Definition.identifier"/> 
      </mapping> 
      <mapping> 
        <identity value="w5"/> 
        <map value="FiveWs.identifier"/> 
      </mapping> 
      <mapping> 
        <identity value="objimpl"/> 
        <map value="no-gen-base"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.version">
      <path value="EvidenceVariable.version"/> 
      <short value="Business version of the evidence variable"/> 
      <definition value="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."/> 
      <comment value="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]."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="EvidenceVariable.version"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="string"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="workflow"/> 
        <map value="Definition.version"/> 
      </mapping> 
      <mapping> 
        <identity value="w5"/> 
        <map value="FiveWs.version"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.name">
      <path value="EvidenceVariable.name"/> 
      <short value="Name for this evidence variable (computer friendly)"/> 
      <definition value="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."/> 
      <comment value="The name is not expected to be globally unique. The name should be a simple alphanumeric
       type name to ensure that it is machine-processing friendly."/> 
      <requirements value="Support human navigation and code generation."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="EvidenceVariable.name"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="string"/> 
      </type> 
      <condition value="inv-0"/> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="EvidenceVariable.title">
      <path value="EvidenceVariable.title"/> 
      <short value="Name for this evidence variable (human friendly)"/> 
      <definition value="A short, descriptive, user-friendly title for the evidence variable."/> 
      <comment value="This name does not need to be machine-processing friendly and may contain punctuation,
       white-space, etc."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="EvidenceVariable.title"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="string"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="workflow"/> 
        <map value="Definition.title"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.shortTitle">
      <path value="EvidenceVariable.shortTitle"/> 
      <short value="Title for use in informal contexts"/> 
      <definition value="The short title provides an alternate title for use in informal descriptive contexts where
       the full, formal title is not necessary."/> 
      <requirements value="Need to be able to reference the content by a short description, but still provide a longer,
       more formal title for the content."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="EvidenceVariable.shortTitle"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="string"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="EvidenceVariable.subtitle">
      <path value="EvidenceVariable.subtitle"/> 
      <short value="Subordinate title of the EvidenceVariable"/> 
      <definition value="An explanatory or alternate title for the EvidenceVariable giving additional information
       about its content."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="EvidenceVariable.subtitle"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="string"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
    </element> 
    <element id="EvidenceVariable.status">
      <path value="EvidenceVariable.status"/> 
      <short value="draft | active | retired | unknown"/> 
      <definition value="The status of this evidence variable. Enables tracking the life-cycle of the content."/> 
      <comment value="Allows filtering of evidence variables that are appropriate for use versus not."/> 
      <min value="1"/> 
      <max value="1"/> 
      <base> 
        <path value="EvidenceVariable.status"/> 
        <min value="1"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="code"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="true"/> 
      <isModifierReason value="This is labeled as &quot;Is Modifier&quot; because applications should not use a retired
       {{title}} without due consideration"/> 
      <isSummary value="true"/> 
      <binding> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="PublicationStatus"/> 
        </extension> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-isCommonBinding">
          <valueBoolean value="true"/> 
        </extension> 
        <strength value="required"/> 
        <description value="The lifecycle status of an artifact."/> 
        <valueSet value="http://hl7.org/fhir/ValueSet/publication-status|4.0.1"/> 
      </binding> 
      <mapping> 
        <identity value="workflow"/> 
        <map value="Definition.status"/> 
      </mapping> 
      <mapping> 
        <identity value="w5"/> 
        <map value="FiveWs.status"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.date">
      <path value="EvidenceVariable.date"/> 
      <short value="Date last changed"/> 
      <definition value="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."/> 
      <comment value="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."/> 
      <alias value="Revision Date"/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="EvidenceVariable.date"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="dateTime"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="workflow"/> 
        <map value="Definition.date"/> 
      </mapping> 
      <mapping> 
        <identity value="w5"/> 
        <map value="FiveWs.recorded"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.publisher">
      <path value="EvidenceVariable.publisher"/> 
      <short value="Name of the publisher (organization or individual)"/> 
      <definition value="The name of the organization or individual that published the evidence variable."/> 
      <comment value="Usually an organization but may be an individual. The publisher (or steward) of the evidence
       variable is the organization or individual primarily responsible for the maintenance and
       upkeep of the evidence variable. This is not necessarily the same individual or organization
       that developed and initially authored the content. The publisher is the primary point
       of contact for questions or issues with the evidence variable. This item SHOULD be populated
       unless the information is available from context."/> 
      <requirements value="Helps establish the &quot;authority/credibility&quot; of the evidence variable.  May also
       allow for contact."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="EvidenceVariable.publisher"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="string"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="workflow"/> 
        <map value="Definition.publisher"/> 
      </mapping> 
      <mapping> 
        <identity value="w5"/> 
        <map value="FiveWs.witness"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.contact">
      <path value="EvidenceVariable.contact"/> 
      <short value="Contact details for the publisher"/> 
      <definition value="Contact details to assist a user in finding and communicating with the publisher."/> 
      <comment value="May be a web site, an email address, a telephone number, etc."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="EvidenceVariable.contact"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="ContactDetail"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="workflow"/> 
        <map value="Definition.contact"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.description">
      <path value="EvidenceVariable.description"/> 
      <short value="Natural language description of the evidence variable"/> 
      <definition value="A free text natural language description of the evidence variable from a consumer's perspective."/> 
      <comment value="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)."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="EvidenceVariable.description"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="markdown"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="workflow"/> 
        <map value="Definition.description"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.note">
      <path value="EvidenceVariable.note"/> 
      <short value="Used for footnotes or explanatory notes"/> 
      <definition value="A human-readable string to clarify or explain concepts about the resource."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="EvidenceVariable.note"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="Annotation"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
    </element> 
    <element id="EvidenceVariable.useContext">
      <path value="EvidenceVariable.useContext"/> 
      <short value="The context that the content is intended to support"/> 
      <definition value="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."/> 
      <comment value="When multiple useContexts are specified, there is no expectation that all or any of the
       contexts apply."/> 
      <requirements value="Assist in searching for appropriate content."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="EvidenceVariable.useContext"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="UsageContext"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="workflow"/> 
        <map value="Definition.useContext"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.jurisdiction">
      <path value="EvidenceVariable.jurisdiction"/> 
      <short value="Intended jurisdiction for evidence variable (if applicable)"/> 
      <definition value="A legal or geographic region in which the evidence variable is intended to be used."/> 
      <comment value="It may be possible for the evidence variable to be used in jurisdictions other than those
       for which it was originally designed or intended."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="EvidenceVariable.jurisdiction"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="CodeableConcept"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <binding> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="Jurisdiction"/> 
        </extension> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-isCommonBinding">
          <valueBoolean value="true"/> 
        </extension> 
        <strength value="extensible"/> 
        <description value="Countries and regions within which this artifact is targeted for use."/> 
        <valueSet value="http://hl7.org/fhir/ValueSet/jurisdiction"/> 
      </binding> 
      <mapping> 
        <identity value="workflow"/> 
        <map value="Definition.jurisdiction"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.copyright">
      <path value="EvidenceVariable.copyright"/> 
      <short value="Use and/or publishing restrictions"/> 
      <definition value="A copyright statement relating to the evidence variable and/or its contents. Copyright
       statements are generally legal restrictions on the use and publishing of the evidence
       variable."/> 
      <requirements value="Consumers must be able to determine any legal restrictions on the use of the evidence
       variable and/or its content."/> 
      <alias value="License"/> 
      <alias value="Restrictions"/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="EvidenceVariable.copyright"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="markdown"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="workflow"/> 
        <map value="Definition.copyright"/> 
      </mapping> 
      <mapping> 
        <identity value="objimpl"/> 
        <map value="no-gen-base"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.approvalDate">
      <path value="EvidenceVariable.approvalDate"/> 
      <short value="When the evidence variable was approved by publisher"/> 
      <definition value="The date on which the resource content was approved by the publisher. Approval happens
       once when the content is officially approved for usage."/> 
      <comment value="The 'date' element may be more recent than the approval date because of minor changes
       or editorial corrections."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="EvidenceVariable.approvalDate"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="date"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="workflow"/> 
        <map value="Definition.approvalDate"/> 
      </mapping> 
      <mapping> 
        <identity value="objimpl"/> 
        <map value="no-gen-base"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.lastReviewDate">
      <path value="EvidenceVariable.lastReviewDate"/> 
      <short value="When the evidence variable was last reviewed"/> 
      <definition value="The date on which the resource content was last reviewed. Review happens periodically
       after approval but does not change the original approval date."/> 
      <comment value="If specified, this date follows the original approval date."/> 
      <requirements value="Gives a sense of how &quot;current&quot; the content is.  Resources that have not been
       reviewed in a long time may have a risk of being less appropriate/relevant."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="EvidenceVariable.lastReviewDate"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="date"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="workflow"/> 
        <map value="Definition.lastReviewDate"/> 
      </mapping> 
      <mapping> 
        <identity value="objimpl"/> 
        <map value="no-gen-base"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.effectivePeriod">
      <path value="EvidenceVariable.effectivePeriod"/> 
      <short value="When the evidence variable is expected to be used"/> 
      <definition value="The period during which the evidence variable content was or is planned to be in active
       use."/> 
      <comment value="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
       to be used for the year 2016 might be published in 2015."/> 
      <requirements value="Allows establishing a transition before a resource comes into effect and also allows for
       a sunsetting  process when new versions of the evidence variable are or are expected to
       be used instead."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="EvidenceVariable.effectivePeriod"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="Period"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="workflow"/> 
        <map value="Definition.effectivePeriod"/> 
      </mapping> 
      <mapping> 
        <identity value="objimpl"/> 
        <map value="no-gen-base"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.topic">
      <path value="EvidenceVariable.topic"/> 
      <short value="The category of the EvidenceVariable, such as Education, Treatment, Assessment, etc."/> 
      <definition value="Descriptive topics related to the content of the EvidenceVariable. Topics provide a high-level
       categorization grouping types of EvidenceVariables that can be useful for filtering and
       searching."/> 
      <requirements value="Repositories must be able to determine how to categorize the EvidenceVariable so that
       it can be found by topical searches."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="EvidenceVariable.topic"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="CodeableConcept"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <binding> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="DefinitionTopic"/> 
        </extension> 
        <strength value="example"/> 
        <description value="High-level categorization of the definition, used for searching, sorting, and filtering."/> 
        <valueSet value="http://hl7.org/fhir/ValueSet/definition-topic"/> 
      </binding> 
    </element> 
    <element id="EvidenceVariable.author">
      <path value="EvidenceVariable.author"/> 
      <short value="Who authored the content"/> 
      <definition value="An individiual or organization primarily involved in the creation and maintenance of the
       content."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="EvidenceVariable.author"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="ContactDetail"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value=".participation[typeCode=AUT]"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.editor">
      <path value="EvidenceVariable.editor"/> 
      <short value="Who edited the content"/> 
      <definition value="An individual or organization primarily responsible for internal coherence of the content."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="EvidenceVariable.editor"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="ContactDetail"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
    </element> 
    <element id="EvidenceVariable.reviewer">
      <path value="EvidenceVariable.reviewer"/> 
      <short value="Who reviewed the content"/> 
      <definition value="An individual or organization primarily responsible for review of some aspect of the content."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="EvidenceVariable.reviewer"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="ContactDetail"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value=".participation[typeCode=VRF] {not clear whether VRF best corresponds to reviewer or endorser}"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.endorser">
      <path value="EvidenceVariable.endorser"/> 
      <short value="Who endorsed the content"/> 
      <definition value="An individual or organization responsible for officially endorsing the content for use
       in some setting."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="EvidenceVariable.endorser"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="ContactDetail"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value=".participation[typeCode=VRF] {not clear whether VRF best corresponds to reviewer or endorser}"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.relatedArtifact">
      <path value="EvidenceVariable.relatedArtifact"/> 
      <short value="Additional documentation, citations, etc."/> 
      <definition value="Related artifacts such as additional documentation, justification, or bibliographic references."/> 
      <comment value="Each related artifact is either an attachment, or a reference to another resource, but
       not both."/> 
      <requirements value="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."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="EvidenceVariable.relatedArtifact"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="RelatedArtifact"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
    </element> 
    <element id="EvidenceVariable.type">
      <path value="EvidenceVariable.type"/> 
      <short value="dichotomous | continuous | descriptive"/> 
      <definition value="The type of evidence element, a population, an exposure, or an outcome."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="EvidenceVariable.type"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="code"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <binding> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="EvidenceVariableType"/> 
        </extension> 
        <strength value="required"/> 
        <description value="The possible types of variables for exposures or outcomes (E.g. Dichotomous, Continuous,
         Descriptive)."/> 
        <valueSet value="http://hl7.org/fhir/ValueSet/variable-type|4.0.1"/> 
      </binding> 
    </element> 
    <element id="EvidenceVariable.characteristic">
      <path value="EvidenceVariable.characteristic"/> 
      <short value="What defines the members of the evidence element"/> 
      <definition value="A characteristic that defines the members of the evidence element. Multiple characteristics
       are applied with &quot;and&quot; semantics."/> 
      <comment value="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."/> 
      <min value="1"/> 
      <max value="*"/> 
      <base> 
        <path value="EvidenceVariable.characteristic"/> 
        <min value="1"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="BackboneElement"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="EvidenceVariable.characteristic.id">
      <path value="EvidenceVariable.characteristic.id"/> 
      <representation value="xmlAttr"/> 
      <short value="Unique id for inter-element referencing"/> 
      <definition value="Unique id for the element within a resource (for internal references). This may be any
       string value that does not contain spaces."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Element.id"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
          <valueUrl value="string"/> 
        </extension> 
        <code value="http://hl7.org/fhirpath/System.String"/> 
      </type> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="n/a"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.characteristic.extension">
      <path value="EvidenceVariable.characteristic.extension"/> 
      <short value="Additional content defined by implementations"/> 
      <definition value="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 manageable, 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."/> 
      <comment value="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."/> 
      <alias value="extensions"/> 
      <alias value="user content"/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="Element.extension"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="Extension"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <constraint> 
        <key value="ext-1"/> 
        <severity value="error"/> 
        <human value="Must have either extensions or value[x], not both"/> 
        <expression value="extension.exists() != value.exists()"/> 
        <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), &quot;value&quot;)])"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="n/a"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.characteristic.modifierExtension">
      <path value="EvidenceVariable.characteristic.modifierExtension"/> 
      <short value="Extensions that cannot be ignored even if unrecognized"/> 
      <definition value="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 manageable,
       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)."/> 
      <comment value="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."/> 
      <requirements value="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](http://hl7.org/f
      hir/extensibility.html#modifierExtension)."/> 
      <alias value="extensions"/> 
      <alias value="user content"/> 
      <alias value="modifiers"/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="BackboneElement.modifierExtension"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="Extension"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <constraint> 
        <key value="ext-1"/> 
        <severity value="error"/> 
        <human value="Must have either extensions or value[x], not both"/> 
        <expression value="extension.exists() != value.exists()"/> 
        <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), &quot;value&quot;)])"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/> 
      </constraint> 
      <isModifier value="true"/> 
      <isModifierReason value="Modifier extensions are expected to modify the meaning or interpretation of the element
       that contains them"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.characteristic.description">
      <path value="EvidenceVariable.characteristic.description"/> 
      <short value="Natural language description of the characteristic"/> 
      <definition value="A short, natural language description of the characteristic that could be used to communicate
       the criteria to an end-user."/> 
      <requirements value="Need to be able to describe characteristics in natural language so that end users can
       understand the criteria."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="EvidenceVariable.characteristic.description"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="string"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
    </element> 
    <element id="EvidenceVariable.characteristic.definition[x]">
      <path value="EvidenceVariable.characteristic.definition[x]"/> 
      <short value="What code or expression defines members?"/> 
      <definition value="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 DataRequirement
      s (such as Diabetes diagnosis onset in the last year)."/> 
      <requirements value="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."/> 
      <min value="1"/> 
      <max value="1"/> 
      <base> 
        <path value="EvidenceVariable.characteristic.definition[x]"/> 
        <min value="1"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="Reference"/> 
        <targetProfile value="http://hl7.org/fhir/StructureDefinition/Group"/> 
      </type> 
      <type> 
        <code value="canonical"/> 
        <targetProfile value="http://hl7.org/fhir/StructureDefinition/ActivityDefinition"/> 
      </type> 
      <type> 
        <code value="CodeableConcept"/> 
      </type> 
      <type> 
        <code value="Expression"/> 
      </type> 
      <type> 
        <code value="DataRequirement"/> 
      </type> 
      <type> 
        <code value="TriggerDefinition"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="EvidenceVariable.characteristic.usageContext">
      <path value="EvidenceVariable.characteristic.usageContext"/> 
      <short value="What code/value pairs define members?"/> 
      <definition value="Use UsageContext to define the members of the population, such as Age Ranges, Genders,
       Settings."/> 
      <requirements value="Need to be able to define members more structurally when more information can be communicated
       such as age range."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="EvidenceVariable.characteristic.usageContext"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="UsageContext"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
    </element> 
    <element id="EvidenceVariable.characteristic.exclude">
      <path value="EvidenceVariable.characteristic.exclude"/> 
      <short value="Whether the characteristic includes or excludes members"/> 
      <definition value="When true, members with this characteristic are excluded from the element."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="EvidenceVariable.characteristic.exclude"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="boolean"/> 
      </type> 
      <meaningWhenMissing value="False"/> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
    </element> 
    <element id="EvidenceVariable.characteristic.participantEffective[x]">
      <path value="EvidenceVariable.characteristic.participantEffective[x]"/> 
      <short value="What time period do participants cover"/> 
      <definition value="Indicates what effective period the study covers."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="EvidenceVariable.characteristic.participantEffective[x]"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="dateTime"/> 
      </type> 
      <type> 
        <code value="Period"/> 
      </type> 
      <type> 
        <code value="Duration"/> 
      </type> 
      <type> 
        <code value="Timing"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
    </element> 
    <element id="EvidenceVariable.characteristic.timeFromStart">
      <path value="EvidenceVariable.characteristic.timeFromStart"/> 
      <short value="Observation time from study start"/> 
      <definition value="Indicates duration from the participant's study entry."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="EvidenceVariable.characteristic.timeFromStart"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="Duration"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
    </element> 
    <element id="EvidenceVariable.characteristic.groupMeasure">
      <path value="EvidenceVariable.characteristic.groupMeasure"/> 
      <short value="mean | median | mean-of-mean | mean-of-median | median-of-mean | median-of-median"/> 
      <definition value="Indicates how elements are aggregated within the study effective period."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="EvidenceVariable.characteristic.groupMeasure"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="code"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <binding> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="GroupMeasure"/> 
        </extension> 
        <strength value="required"/> 
        <description value="Possible group measure aggregates (E.g. Mean, Median)."/> 
        <valueSet value="http://hl7.org/fhir/ValueSet/group-measure|4.0.1"/> 
      </binding> 
    </element> 
  </snapshot> 
  <differential> 
    <element id="EvidenceVariable">
      <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-display-hint">
        <valueString value="0;0"/> 
      </extension> 
      <path value="EvidenceVariable"/> 
      <comment value="PICO stands for Population (the population within which exposures are being compared),
       Intervention (the conditional state or exposure state being described for its effect on
       outcomes), Comparison (the alternative conditional state or alternative exposure state
       being compared against), and Outcome (the result or effect of the intervention in the
       population)."/> 
      <min value="0"/> 
      <max value="*"/> 
      <mapping> 
        <identity value="workflow"/> 
        <map value="Definition"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.identifier">
      <path value="EvidenceVariable.identifier"/> 
      <short value="Additional identifier for the evidence variable"/> 
      <definition value="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."/> 
      <comment value="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."/> 
      <requirements value="Allows externally provided and/or usable business identifiers to be easily associated
       with the module."/> 
      <min value="0"/> 
      <max value="*"/> 
      <type> 
        <code value="Identifier"/> 
      </type> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="workflow"/> 
        <map value="Definition.identifier"/> 
      </mapping> 
      <mapping> 
        <identity value="objimpl"/> 
        <map value="no-gen-base"/> 
      </mapping> 
      <mapping> 
        <identity value="w5"/> 
        <map value="FiveWs.identifier"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.title">
      <path value="EvidenceVariable.title"/> 
      <short value="Name for this evidence variable (human friendly)"/> 
      <definition value="A short, descriptive, user-friendly title for the evidence variable."/> 
      <comment value="This name does not need to be machine-processing friendly and may contain punctuation,
       white-space, etc."/> 
      <min value="0"/> 
      <max value="1"/> 
      <type> 
        <code value="string"/> 
      </type> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="workflow"/> 
        <map value="Definition.title"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.shortTitle">
      <path value="EvidenceVariable.shortTitle"/> 
      <short value="Title for use in informal contexts"/> 
      <definition value="The short title provides an alternate title for use in informal descriptive contexts where
       the full, formal title is not necessary."/> 
      <requirements value="Need to be able to reference the content by a short description, but still provide a longer,
       more formal title for the content."/> 
      <min value="0"/> 
      <max value="1"/> 
      <type> 
        <code value="string"/> 
      </type> 
    </element> 
    <element id="EvidenceVariable.date">
      <path value="EvidenceVariable.date"/> 
      <short value="Date last changed"/> 
      <definition value="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."/> 
      <comment value="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."/> 
      <alias value="Revision Date"/> 
      <min value="0"/> 
      <max value="1"/> 
      <type> 
        <code value="dateTime"/> 
      </type> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="workflow"/> 
        <map value="Definition.date"/> 
      </mapping> 
      <mapping> 
        <identity value="w5"/> 
        <map value="FiveWs.recorded"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.description">
      <path value="EvidenceVariable.description"/> 
      <short value="Natural language description of the evidence variable"/> 
      <definition value="A free text natural language description of the evidence variable from a consumer's perspective."/> 
      <comment value="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)."/> 
      <min value="0"/> 
      <max value="1"/> 
      <type> 
        <code value="markdown"/> 
      </type> 
      <mapping> 
        <identity value="workflow"/> 
        <map value="Definition.description"/> 
      </mapping> 
    </element> 
    <element id="EvidenceVariable.note">
      <path value="EvidenceVariable.note"/> 
      <short value="Used for footnotes or explanatory notes"/> 
      <definition value="A human-readable string to clarify or explain concepts about the resource."/> 
      <min value="0"/> 
      <max value="*"/> 
      <type> 
        <code value="Annotation"/> 
      </type> 
    </element> 
    <element id="EvidenceVariable.type">
      <path value="EvidenceVariable.type"/> 
      <short value="dichotomous | continuous | descriptive"/> 
      <definition value="The type of evidence element, a population, an exposure, or an outcome."/> 
      <min value="0"/> 
      <max value="1"/> 
      <type> 
        <code value="code"/> 
      </type> 
    </element> 
    <element id="EvidenceVariable.characteristic">
      <path value="EvidenceVariable.characteristic"/> 
      <short value="What defines the members of the evidence element"/> 
      <definition value="A characteristic that defines the members of the evidence element. Multiple characteristics
       are applied with &quot;and&quot; semantics."/> 
      <comment value="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."/> 
      <min value="1"/> 
      <max value="*"/> 
    </element> 
    <element id="EvidenceVariable.characteristic.description">
      <path value="EvidenceVariable.characteristic.description"/> 
      <short value="Natural language description of the characteristic"/> 
      <definition value="A short, natural language description of the characteristic that could be used to communicate
       the criteria to an end-user."/> 
      <requirements value="Need to be able to describe characteristics in natural language so that end users can
       understand the criteria."/> 
      <min value="0"/> 
      <max value="1"/> 
      <type> 
        <code value="string"/> 
      </type> 
    </element> 
    <element id="EvidenceVariable.characteristic.definition[x]">
      <path value="EvidenceVariable.characteristic.definition[x]"/> 
      <short value="What code or expression defines members?"/> 
      <definition value="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 DataRequirement
      s (such as Diabetes diagnosis onset in the last year)."/> 
      <requirements value="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."/> 
      <min value="1"/> 
      <max value="1"/> 
      <type> 
        <code value="Reference"/> 
        <targetProfile value="http://hl7.org/fhir/StructureDefinition/Group"/> 
      </type> 
      <type> 
        <code value="canonical"/> 
        <targetProfile value="http://hl7.org/fhir/StructureDefinition/ActivityDefinition"/> 
      </type> 
      <type> 
        <code value="CodeableConcept"/> 
      </type> 
      <type> 
        <code value="Expression"/> 
      </type> 
      <type> 
        <code value="DataRequirement"/> 
      </type> 
      <type> 
        <code value="TriggerDefinition"/> 
      </type> 
    </element> 
    <element id="EvidenceVariable.characteristic.usageContext">
      <path value="EvidenceVariable.characteristic.usageContext"/> 
      <short value="What code/value pairs define members?"/> 
      <definition value="Use UsageContext to define the members of the population, such as Age Ranges, Genders,
       Settings."/> 
      <requirements value="Need to be able to define members more structurally when more information can be communicated
       such as age range."/> 
      <min value="0"/> 
      <max value="*"/> 
      <type> 
        <code value="UsageContext"/> 
      </type> 
    </element> 
    <element id="EvidenceVariable.characteristic.exclude">
      <path value="EvidenceVariable.characteristic.exclude"/> 
      <short value="Whether the characteristic includes or excludes members"/> 
      <definition value="When true, members with this characteristic are excluded from the element."/> 
      <min value="0"/> 
      <max value="1"/> 
      <type> 
        <code value="boolean"/> 
      </type> 
    </element> 
    <element id="EvidenceVariable.characteristic.participantEffective[x]">
      <path value="EvidenceVariable.characteristic.participantEffective[x]"/> 
      <short value="What time period do participants cover"/> 
      <definition value="Indicates what effective period the study covers."/> 
      <min value="0"/> 
      <max value="1"/> 
      <type> 
        <code value="dateTime"/> 
      </type> 
      <type> 
        <code value="Period"/> 
      </type> 
      <type> 
        <code value="Duration"/> 
      </type> 
      <type> 
        <code value="Timing"/> 
      </type> 
    </element> 
    <element id="EvidenceVariable.characteristic.timeFromStart">
      <path value="EvidenceVariable.characteristic.timeFromStart"/> 
      <short value="Observation time from study start"/> 
      <definition value="Indicates duration from the participant's study entry."/> 
      <min value="0"/> 
      <max value="1"/> 
      <type> 
        <code value="Duration"/> 
      </type> 
    </element> 
    <element id="EvidenceVariable.characteristic.groupMeasure">
      <path value="EvidenceVariable.characteristic.groupMeasure"/> 
      <short value="mean | median | mean-of-mean | mean-of-median | median-of-mean | median-of-median"/> 
      <definition value="Indicates how elements are aggregated within the study effective period."/> 
      <min value="0"/> 
      <max value="1"/> 
      <type> 
        <code value="code"/> 
      </type> 
    </element> 
  </differential> 
</StructureDefinition>