{description: Return prescriptions written on this date, package_name: hl7.fhir.r4b.core, name: datewritten, type: date, package_version: 4.3.0-snapshot1, class: unknown, kind: null, url: 'http://hl7.org/fhir/SearchParameter/VisionPrescription-datewritten', version: 4.3.0-snapshot1}