http://hl7.org/fhir/StructureDefinition/observation-precondition|5.2.0
Other preceding or concurrent observations that must be known to understand the context and significance of the observation. For example, an fiO2 measure taken alongside of a SpO2 measurement. See the FHIR specification [Observation notes](http://hl7.org/fhir/observation.html#notes) section for additional guidance.
description: Other preceding or concurrent observations that must be known to understand the context and significance of the observation. For example, an fiO2 measure taken alongside of a SpO2 measurement. See the FHIR specification [Observation notes](http://hl7.org/fhir/observation.html#notes) section for additional guidance. derivation: constraint name: ObsPrecondition type: Extension elements: extension: {index: 0} url: pattern: {type: Uri, value: 'http://hl7.org/fhir/StructureDefinition/observation-precondition'} index: 1 value: choices: [] index: 3 extensions: {} class: extension kind: complex-type url: http://hl7.org/fhir/StructureDefinition/observation-precondition base: http://hl7.org/fhir/StructureDefinition/Extension version: 5.2.0 required: [value]