http://hl7.org/fhir/StructureDefinition/observation-precondition|4.0.1

Other preceding or concurrent observations that must be known to correctly interpret the the observation. For example an fiO2 measure taken alongside of a SpO2 measurement. See the [Observation notes](observation.html#notes) section for additional guidance.
description: Other preceding or concurrent observations that must be known to correctly interpret the the observation.  For example an fiO2 measure taken alongside of a SpO2 measurement.  See the [Observation notes](observation.html#notes) section for additional guidance.
derivation: constraint
name: precondition
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: 4.0.1
required: [value]