ResearchDefinition on the FHIR specification website.

The ResearchDefinition 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.

The body should be a valid FHIR object for ResearchDefinition.

Here is an example:

{
  "resourceType": "ResearchDefinition",
  "id": "example",
  "text": {
    "status": "generated",
    "div": "<div xmlns=\"http://www.w3.org/1999/xhtml\">[Put rendering here]</div>"
  },
  "status": "draft",
  "population": {
    "reference": "ResearchElementDefinition/example"
  }
}

You can reference the FHIR documentation to determine the format for ResearchDefinition.