Evidence resource (FHIR R4)

Evidence is the FHIR R4 resource for the Evidence resource describes the conditional state (population and any exposures being compared within the population) and outcome (if specified) that the knowledge (evidence, assertion, recommendation) is about.

Resource	Evidence
FHIR version	R4 (4.0.1)
Canonical URL	http://hl7.org/fhir/StructureDefinition/Evidence
Required elements	status (1..1), exposureBackground (1..1)

Example

{
  "resourceType": "Evidence",
  "id": "evidence-b1cb111e4245c766c8bc0db299f4a856",
  "status": "draft",
  "exposureBackground": {
    "reference": "EvidenceVariable/evidencevariable-05060cb93d99db0351867440b8207dbb"
  }
}

Generated by the Pidgeon engine: pidgeon generate Evidence --seed 20260722.

Validation context

strict pidgeon validate grades a Evidence instance against the base R4 structure definition: missing required elements raise REQUIRED_FIELD_MISSING and cardinality violations raise CARDINALITY_MIN or CARDINALITY_MAX.(REQUIRED_FIELD_MISSING)

This answer, in your terminal

pidgeon lookup Evidence

Wire it into your AI agent:

claude mcp add pidgeon -- npx -y @pidgeonhealth/mcp

Download Post free to browse this reference with generation attached.