---
type: "codesystem"
title: "Evidence Variable Event"
codesystem: "evidence-variable-event"
---
# Evidence Variable Event

- **Official URL**: http://hl7.org/fhir/evidence-variable-event
- **Version**: 6.0.0
- **Status**: active
- **Name**: EvidenceVariableEvent
- **Title**: Evidence Variable Event
- **Publisher**: HL7 (FHIR Project)
- **Description**: The event used as a base point (reference point) in time.
- **Case Sensitive**: true
- **Content**: complete

## Concepts

| Code | Display | Definition |
| --- | --- | --- |
| study-start | Study Start | The time of enrollment for the study participant |
| treatment-start | Start of Treatment | The time of initiation of the treatment |
| condition-detection | Detection of Condition | The time of first detection of the condition |
| condition-treatment | Treatment of Condition | The time of first treatment of the condition |
| hospital-admission | Hospital Admission | The time of admission to the hospital |
| hospital-discharge | Hospital Discharge | The time of discharge from the hospital |
| operative-procedure | Operative Procedure | The time of surgery |

## CodeSystem XML



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

<CodeSystem xmlns="http://hl7.org/fhir">
  <id value="evidence-variable-event"/>
  <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="normative"/>
  </extension>
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm">
    <valueInteger value="5"/>
  </extension>
  <url value="http://hl7.org/fhir/evidence-variable-event"/>
  <identifier>
    <system value="urn:ietf:rfc:3986"/>
    <value value="urn:oid:2.16.840.1.113883.4.642.4.1955"/>
  </identifier>
  <version value="6.0.0"/>
  <name value="EvidenceVariableEvent"/>
  <title value="Evidence Variable Event"/>
  <status value="active"/>
  <experimental value="false"/>
  <date value="2021-01-05T10:01:24+11:00"/>
  <publisher value="HL7 (FHIR Project)"/>
  <contact>
    <telecom>
      <system value="url"/>
      <value value="http://hl7.org/fhir"/>
    </telecom>
    <telecom>
      <system value="email"/>
      <value value="fhir@lists.hl7.org"/>
    </telecom>
  </contact>
  <description value="The event used as a base point (reference point) in time."/>
  <caseSensitive value="true"/>
  <valueSet value="http://hl7.org/fhir/ValueSet/evidence-variable-event"/>
  <content value="complete"/>
  <concept>
    <code value="study-start"/>
    <display value="Study Start"/>
    <definition value="The time of enrollment for the study participant"/>
  </concept>
  <concept>
    <code value="treatment-start"/>
    <display value="Start of Treatment"/>
    <definition value="The time of initiation of the treatment"/>
  </concept>
  <concept>
    <code value="condition-detection"/>
    <display value="Detection of Condition"/>
    <definition value="The time of first detection of the condition"/>
  </concept>
  <concept>
    <code value="condition-treatment"/>
    <display value="Treatment of Condition"/>
    <definition value="The time of first treatment of the condition"/>
  </concept>
  <concept>
    <code value="hospital-admission"/>
    <display value="Hospital Admission"/>
    <definition value="The time of admission to the hospital"/>
  </concept>
  <concept>
    <code value="hospital-discharge"/>
    <display value="Hospital Discharge"/>
    <definition value="The time of discharge from the hospital"/>
  </concept>
  <concept>
    <code value="operative-procedure"/>
    <display value="Operative Procedure"/>
    <definition value="The time of surgery"/>
  </concept>
</CodeSystem>
```