{
  "resourceType": "ResearchSubject",
  "id": "example-crossover-placebo-to-drug",
  "identifier": [
    {
      "value": "ecsr45"
    }
  ],
  "status": "active",
  "period": {
    "start": "2022-06-10"
  },
  "study": {
    "reference": "example-ctgov-study-record"
  },
  "subject": {
    "reference": "cfsb1676546565857"
  },
  "comparisonGroup": [
    {
      "concept": {
        "coding": [
          {
            "system": "http://hl7.org/fhir/example-comparison-group",
            "code": "placebo",
            "display": "Placebo"
          }
        ]
      }
    },
    {
      "concept": {
        "text": "ap303"
      }
    }
  ],
  "meta": {
    "tag": [
      {
        "system": "http://terminology.hl7.org/CodeSystem/v3-ActReason",
        "code": "HTEST",
        "display": "test health data"
      }
    ]
  }
}