description: Describes how to combine the information calculated, based on logic in each of several populations, into one summarized result. package_name: hl7.fhir.uv.cqm derivation: constraint name: CQMRateAggregation type: Extension elements: url: type: uri pattern: {type: Uri, value: 'http://hl7.org/fhir/uv/cqm/StructureDefinition/cqm-rateAggregation'} index: 0 value: choices: [valueString] index: 2 valueString: {type: string, choiceOf: value, index: 3} package_version: 1.0.0-ballot class: extension kind: complex-type url: http://hl7.org/fhir/uv/cqm/StructureDefinition/cqm-rateAggregation base: http://hl7.org/fhir/StructureDefinition/Extension version: 1.0.0