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

  <!-- 
 This is an example of a cancelled standard blood pressure measurement. with an Observation/component/dataAbsentReason valued due to cancellation.

 Blood Pressure is a regarded as a single observation, and
 presented that way in plain text: 120/80. Also, it is usually
 interpreted as a single value, though intepretation can also
 be offered to the parts individually

 Technically, though, a blood pressure is a pair of component
 observations. LOINC code 85354-9 notes say:
   This term is intended as a section header for various
   blood pressure measurements (e.g. systolic, diastolic).
   LOINC discourages the reporting of two numbers, such as
   systolic and diastolic blood pressure (e.g. 120/80),
   in one observation. They should be reported as two
   separate variables, systolic (LOINC 8480-6) and
   diastolic (LOINC 8462-4)

 This example shows the standard way to represent a meaurement that cause the expected values to be empty
 single resource, with a narrative in the standard form, and two
 component observations for the actual values with Observation/component/dataAbsentReason valued due to cancellation


 -->
<Observation xmlns="http://hl7.org/fhir">
  <id value="blood-pressure-cancel"/>
  <meta>
    <profile value="http://hl7.org/fhir/StructureDefinition/vitalsigns"/>
  </meta>
  <!-- 	EH  Narrative created by build
	<text>
		<status value="generated"/>
		<div xmlns="http://www.w3.org/1999/xhtml">Sept 17, 2012: Systolic Blood pressure 107/60 mmHg (low)</div>
	</text>
 -->
  <identifier>
    <system value="urn:ietf:rfc:3986"/>
    <value value="urn:uuid:187e0c12-8dd2-67e2-99b2-bf273c878281"/>
  </identifier>
  <status value="cancelled"/>
  <category>
    <coding>
      <system value="http://terminology.hl7.org/CodeSystem/observation-category"/>
      <code value="vital-signs"/>
      <display value="Vital Signs"/>
    </coding>
  </category>
  <code>
    <!--  replaced by 85354-9
		<coding>
			<system value="http://loinc.org"/>
			<code value="85354-9"/>
			<display value="Blood pressure systolic &amp; diastolic"/>
		</coding>
 -->
    <coding>
      <system value="http://loinc.org"/>
      <code value="85354-9"/>
      <display value="Blood pressure panel with all children optional"/>
    </coding>
    <text value="Blood pressure systolic &amp; diastolic"/>
  </code>
  <subject>
    <reference value="Patient/example"/>
  </subject>
  <effectiveDateTime value="2012-09-17"/>
  <performer>
    <reference value="Practitioner/example"/>
  </performer>
  <!--  an interpretation offered to the combination observation
        generally, it would only be appropriate to offer an interpretation
        of an observation that has no value if it has "COMP" (component)
        observations  -->
  <interpretation>
    <coding>
      <system value="http://terminology.hl7.org/CodeSystem/v3-ObservationInterpretation"/>
      <code value="L"/>
      <display value="low"/>
    </coding>
    <text value="Below low normal"/>
  </interpretation>
  <note>
    <text value="In this example, the blood pressure measurements are not available due to cancellation of the order.  Data absent reason is present for each component"/>
  </note>
  <!--  for an observation with components, these cannot disagree with the flags on the components  -->
  <bodySite>
    <coding>
      <system value="http://snomed.info/sct"/>
      <code value="368209003"/>
      <display value="Right arm"/>
    </coding>
  </bodySite>
  <component>
    <!-- 
           Observations are often coded in multiple code systems.
           - LOINC provides a very specific code (though not usefully more specific in this particular case)
           - snomed provides a clinically relevant code that is usually less granular than LOINC
           - the source system provides its own code, which may be less or more granular than LOINC
	 this instance shows the concept. The other codes only have a LOINC code  -->
    <!--  that shows the concept. The next two names only have a LOINC code  -->
    <code>
      <!--  LOINC - always recommended to have a LOINC code  -->
      <coding>
        <system value="http://loinc.org"/>
        <code value="8480-6"/>
        <display value="Systolic blood pressure"/>
      </coding>
      <!--  SNOMED CT Codes - becoming more common  -->
      <coding>
        <system value="http://snomed.info/sct"/>
        <code value="271649006"/>
        <display value="Systolic blood pressure"/>
      </coding>
      <!--  Also, a local code specific to the source system  -->
      <coding>
        <system value="http://acme.org/devices/clinical-codes"/>
        <code value="bp-s"/>
        <display value="Systolic Blood pressure"/>
      </coding>
    </code>
    <!--  no value due to some error
    <valueQuantity>
      <value value="107"/>
      <unit value="mm[Hg]"/>
    </valueQuantity>
 -->
    <dataAbsentReason>
      <coding>
        <system value="http://terminology.hl7.org/CodeSystem/data-absent-reason"/>
        <code value="not-asked"/>
        <display value="Not Asked"/>
      </coding>
    </dataAbsentReason>
  </component>
  <component>
    <code>
      <coding>
        <system value="http://loinc.org"/>
        <code value="8462-4"/>
        <display value="Diastolic blood pressure"/>
      </coding>
    </code>
    <!--  no value due to some error
    <valueQuantity>
      <value value="60"/>
      <unit value="mm[Hg]"/>
    </valueQuantity>
 -->
    <dataAbsentReason>
      <coding>
        <system value="http://terminology.hl7.org/CodeSystem/data-absent-reason"/>
        <code value="not-asked"/>
        <display value="Not Asked"/>
      </coding>
    </dataAbsentReason>
  </component>
</Observation>