In the EventDefinition resource for FHIR r4 , the lastReviewDate attribute identifies the When the event definition was last reviewed
"lastReviewDate":
"url":
"identifier":
"version":
"name":
"title":
"subtitle":
"status": "draft"
"experimental":
"subject[x]":
"date":
"publisher":
"contact":
"description":
"useContext":
"jurisdiction":
"purpose": "Monitor all admissions to Emergency"
"usage":
"copyright":
"approvalDate":
"lastReviewDate":
"effectivePeriod":
"topic":
"author":
"editor":
"reviewer":
"endorser":
"relatedArtifact":
"trigger": [
{
"type": "named-event",
"name": "monitor-emergency-admissions",
"data": [
{
"type": "Encounter"
}
],
"condition": {
"description": "Encounter Location = emergency (active/completed encounters, current or previous)",
"language": "text/fhirpath",
"expression": "(this | %previous).location.where(location = 'Location/emergency' and status in {'active', 'completed'}).exists()"
}
}
]