description: This profile sets minimum expectations for an Observation resource to record, search, and fetch waist circumference observations with standard coding and units of measure. It is based on the [FHIR Vital Signs Profile](http://hl7.org/fhir/R4/vitalsigns.html) and identifies the *additional* mandatory core elements, extensions, vocabularies and value sets that **SHALL** be present in the Observation resource when conforming to this profile. It provides the floor for standards development for specific uses cases in an Australian context.
package_name: hl7.fhir.au.core
derivation: constraint
name: AUCoreWaistCircumference
type: Observation
elements:
  encounter:
    type: Reference
    mustSupport: true
    refers: ['http://hl7.org.au/fhir/core/StructureDefinition/au-core-encounter']
    index: 9
  valueQuantity:
    short: Waist circumference
    index: 14
    elements:
      value: {type: decimal, index: 15}
      unit: {type: string, index: 16}
      system:
        type: uri
        pattern: {type: Uri, value: 'http://unitsofmeasure.org'}
        index: 17
      code:
        type: code
        short: Coded responses from the common UCUM units for vital signs value set.
        binding: {strength: required, valueSet: 'https://healthterminologies.gov.au/fhir/ValueSet/metric-body-length-units-1'}
        index: 18
    required: [value, unit, system, code]
  effectiveDateTime:
    type: dateTime
    short: Date, and optionally time, the observation was performed
    constraint:
      au-core-obs-01: {human: Date shall be at least to day, source: 'http://hl7.org.au/fhir/core/StructureDefinition/au-core-waistcircum', severity: error, expression: $this is DateTime implies $this.toString().length() >= 10}
    choiceOf: effective
    index: 12
  status:
    pattern: {type: Code, value: final}
    index: 0
  effective:
    short: Date, and optionally time, the observation was performed
    constraint:
      au-core-obs-01: {human: Date shall be at least to day, source: 'http://hl7.org.au/fhir/core/StructureDefinition/au-core-waistcircum', severity: error, expression: $this is DateTime implies $this.toString().length() >= 10}
    choices: [effectiveDateTime]
    index: 11
  code:
    elements:
      coding:
        array: true
        min: 2
        index: 1
        slicing:
          rules: open
          ordered: false
          discriminator:
          - {path: code, type: value}
          - {path: system, type: value}
          min: 2
          slices:
            loincWaistCircumCode:
              match: {code: 8280-0, system: 'http://loinc.org'}
              schema:
                short: LOINC Waist Circumference
                _required: true
                index: 2
                elements:
                  system:
                    pattern: {type: Uri, value: 'http://loinc.org'}
                    index: 3
                  code:
                    pattern: {type: Code, value: 8280-0}
                    index: 4
                required: [system, code]
            snomedWaistCircumCode:
              match: {code: '276361009', system: 'http://snomed.info/sct'}
              schema:
                short: SNOMED CT Waist Circumference
                _required: true
                index: 5
                elements:
                  system:
                    pattern: {type: Uri, value: 'http://snomed.info/sct'}
                    index: 6
                  code:
                    pattern: {type: Code, value: '276361009'}
                    index: 7
                required: [system, code]
  bodySite:
    binding: {strength: preferred, valueSet: 'https://healthterminologies.gov.au/fhir/ValueSet/body-site-1'}
    constraint:
      au-core-obs-04: {human: 'If a coded body site is provided, at least one code shall be from SNOMED CT', source: 'http://hl7.org.au/fhir/core/StructureDefinition/au-core-waistcircum', severity: error, expression: 'coding.exists() implies coding.where(system=''http://snomed.info/sct'').exists()'}
    index: 20
  subject:
    type: Reference
    refers: ['http://hl7.org.au/fhir/core/StructureDefinition/au-core-patient']
    index: 8
  performer:
    type: Reference
    mustSupport: true
    refers: ['http://hl7.org.au/fhir/core/StructureDefinition/au-core-organization', 'http://hl7.org.au/fhir/core/StructureDefinition/au-core-patient', 'http://hl7.org.au/fhir/core/StructureDefinition/au-core-practitioner', 'http://hl7.org.au/fhir/core/StructureDefinition/au-core-practitionerrole', 'http://hl7.org.au/fhir/core/StructureDefinition/au-core-relatedperson']
    index: 13
  dataAbsentReason: {mustSupport: true, index: 19}
package_version: 0.2.2-preview
class: profile
kind: resource
url: http://hl7.org.au/fhir/core/StructureDefinition/au-core-waistcircum
base: http://hl7.org/fhir/StructureDefinition/vitalsigns
version: 0.2.2-preview