description: This profile sets minimum expectations for an Observation resource to record, search, and fetch observations that represent simple measurements and assertions about a patient. It is based on the core FHIR [Observation](http://hl7.org/fhir/R4/observation.html) resource 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: AUCoreObservation type: Observation elements: category: {mustSupport: true, index: 1} encounter: type: Reference mustSupport: true refers: ['http://hl7.org.au/fhir/core/StructureDefinition/au-core-encounter'] index: 4 value: mustSupport: true choices: [] index: 10 note: {mustSupport: true, index: 12} effectiveDateTime: constraint: au-core-obs-01: {human: Date shall be at least to day, source: 'http://hl7.org.au/fhir/core/StructureDefinition/au-core-observation', severity: error, expression: $this is DateTime implies $this.toString().length() >= 10} short: Date, and optionally time, the observation was performed type: dateTime mustSupport: true choiceOf: effective index: 7 status: {mustSupport: true, index: 0} effective: constraint: au-core-obs-01: {human: Date shall be at least to day, source: 'http://hl7.org.au/fhir/core/StructureDefinition/au-core-observation', severity: error, expression: $this is DateTime implies $this.toString().length() >= 10} short: Date, and optionally time, the observation was performed mustSupport: true choices: [effectiveDateTime] index: 6 code: {mustSupport: true, index: 2} subject: type: Reference mustSupport: true refers: ['http://hl7.org.au/fhir/core/StructureDefinition/au-core-patient'] index: 3 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: 8 dataAbsentReason: {mustSupport: true, index: 11} package_version: 0.2.2-preview class: profile kind: resource url: http://hl7.org.au/fhir/core/StructureDefinition/au-core-observation base: http://hl7.org/fhir/StructureDefinition/Observation version: 0.2.2-preview required: [effectiveDateTime, subject, category, effective]