<?xml version=“1.0” encoding=“UTF-8”?> <Observation xmlns=“hl7.org/fhir”>
<id value="herd1"/> <!-- the mandatory status --> <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 code is A code that classifies the general type of observation being made. This is used for searching, sorting and display purposes. --> <category> <coding> <system value="http://terminology.hl7.org/CodeSystem/observation-category"/> <code value="laboratory"/> <display value="Laboratory"/> </coding> <text value="Laboratory"/> </category> <!-- Observations are often coded in multiple code systems. - LOINC provides codes of varying granularity (though not usefully more specific in this particular case) and more generic LOINCs can be mapped to more specific codes as shown here - 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 --> <code> <!-- LOINC - always recommended to have a LOINC code --> <coding> <system value="http://loinc.org"/> <code value="80219-9"/> <!-- more generic methodless LOINC --> <display value="Mycoplasma hyopneumoniae Ab sample/Positive control in Serum by Immunoassay"/> </coding> <!-- Also, a local code specific to the source system --> <coding> <system value="http://acme.org/devices/clinical-codes"/> <code value="Mycoplasma"/> <display value="Mycoplasma"/> </coding> <text value="Mycoplasma hyopneumoniae - MHP"/> </code> <!-- subject is a herd of 2500 breding sows --> <subject> <reference value="Group/herd1"/> </subject> <encounter> <display value="part of a health assurance program"/> </encounter> <effectiveDateTime value="2017-11-20"/> <!-- In FHIR, units may be represented twice. Once in the agreed human representation, and once in a coded form. Both is best, since it's not always possible to infer one from the other in code. When a computable unit is provided, UCUM (http://unitsofmeasure.org) is always preferred, but it doesn't provide notional units (such as "tablet"), etc. For these, something else is required (e.g. SNOMED CT) --> <valueQuantity> <value value="0.2"/> <unit value="% (sample/positive control)"/> <system value="http://unitsofmeasure.org"/> <code value="%"/> </valueQuantity> <interpretation> <coding> <system value="http://terminology.hl7.org/CodeSystem/v3-ObservationInterpretation"/> <code value="NEG"/> <display value="Negative"/> </coding> <text value="Negative"/> </interpretation> <!-- Specimen is a pooled serology sample of 30 animals. --> <specimen> <reference value="Specimen/pooled-serum"/> <display value="30 serum"/> </specimen> <referenceRange> <text value=">0.4 Positive; 0.3 to 0.4 Suspect < 0.3 Negative"/> </referenceRange>
</Observation>