<status value="active" /> <date value="2026-02-26" /> <publisher value="NHS Wales" /> <contact> <name value="NHS Wales" /> <telecom> <system value="email" /> <value value="fhir.standards@wales.nhs.uk" /> <use value="work" /> <rank value="1" /> </telecom> </contact> <description value="Resource structure is derived from Data Standards Wales - Observation - Vital Signs. It has drawn on UK Core - Observation - BMI v 1.0.0 (not yet included in a balloted release) for guidance on specific content and constraints for use when the observation is a BMI measurement." /> <purpose value="To provide implementers with additional support when implementing measuring and recording body mass index and to provide a consistent structure to how the data is presented." /> <copyright value="2026 NHS Wales" /> <fhirVersion value="4.0.1" /> <kind value="resource" /> <abstract value="false" /> <type value="Observation" /> <baseDefinition value="https://fhir.nhs.wales/StructureDefinition/DataStandardsWales-Observation-VitalSigns" /> <derivation value="constraint" /> <differential> <element id="Observation.code.coding:loinc"> <path value="Observation.code.coding" /> <sliceName value="loinc" /> </element> <element id="Observation.code.coding:loinc.code"> <path value="Observation.code.coding.code" /> <fixedCode value="39156-5" /> </element> <element id="Observation.code.coding:snomedCT"> <path value="Observation.code.coding" /> <sliceName value="snomedCT" /> <min value="1" /> <max value="1" /> <binding> <strength value="preferred" /> <valueSet value="https://fhir.nhs.wales/ValueSet/DataStandardsWales-BMI" /> </binding> </element> <element id="Observation.code.coding:snomedCT.system"> <path value="Observation.code.coding.system" /> <min value="1" /> </element> <element id="Observation.code.coding:snomedCT.code"> <path value="Observation.code.coding.code" /> <min value="1" /> </element> <element id="Observation.value[x]"> <path value="Observation.value[x]" /> <min value="1" /> <type> <code value="Quantity" /> </type> </element> <element id="Observation.value[x].value"> <path value="Observation.value[x].value" /> <min value="1" /> </element> <element id="Observation.value[x].system"> <path value="Observation.value[x].system" /> <min value="1" /> <fixedUri value="http://unitsofmeasure.org" /> </element> <element id="Observation.value[x].code"> <path value="Observation.value[x].code" /> <min value="1" /> <fixedCode value="kg/m2" /> </element> <element id="Observation.note.author[x]"> <path value="Observation.note.author[x]" /> <type> <code value="Reference" /> <targetProfile value="https://fhir.nhs.wales/StructureDefinition/DataStandardsWales-Organization" /> <targetProfile value="https://fhir.nhs.wales/StructureDefinition/DataStandardsWales-RelatedPerson" /> <targetProfile value="https://fhir.nhs.wales/StructureDefinition/DataStandardsWales-Patient" /> <targetProfile value="https://fhir.nhs.wales/StructureDefinition/DataStandardsWales-Practitioner" /> </type> <type> <code value="string" /> </type> </element> </differential> </StructureDefinition>