<?xml version="1.0" encoding="UTF-8"?><Observation xmlns="http://hl7.org/fhir">
  <id value="bmi-using-related"/>
  <!--  ======== need to fix vitals to removed fixed value 'has-member' ==========
	<meta>
		<profile value="http://hl7.org/fhir/StructureDefinition/vitalsigns"/>
	</meta>
     -->
  <meta>
    <security>
      <system value="http://terminology.hl7.org/CodeSystem/v3-ActReason"/>
      <code value="HTEST"/>
      <display value="test health data"/>
    </security>
  </meta>
  <status value="final"/>
  <category>
    <coding>
      <system value="http://terminology.hl7.org/CodeSystem/observation-category"/>
      <code value="vital-signs"/>
      <display value="Vital Signs"/>
    </coding>
    <text value="Vital Signs"/>
  </category>
  <category>
    <coding>
      <system value="http://loinc.org"/>
      <code value="39156-5"/>
      <display value="Body mass index (BMI) [Ratio]"/>
    </coding>
  </category>
  <code>
    <coding>
      <system value="http://loinc.org"/>
      <code value="39156-5"/>
      <display value="Body mass index (BMI) [Ratio]"/>
    </coding>
    <text value="BMI"/>
  </code>
  <subject>
    <reference value="Patient/example"/>
  </subject>
  <effectiveDateTime value="1999-07-02"/>
  <valueQuantity>
    <value value="16.2"/>
    <unit value="kg/m2"/>
    <system value="http://unitsofmeasure.org"/>
    <code value="kg/m2"/>
  </valueQuantity>
  <derivedFrom>
    <reference value="Observation/bodyheight"/>
    <display value="Body Height"/>
  </derivedFrom>
  <derivedFrom>
    <reference value="Observation/example"/>
    <display value="Body Weight"/>
  </derivedFrom>
</Observation>