ResearchSubject

Overview

The ResearchSubject resource describes a patient's participation in a clinical trial or research study. It links the patient to the study and tracks their enrollment status and assigned study arm.

FHIR R4 Specification

See the official HL7 specification: https://hl7.org/fhir/R4/researchsubject.html

Supported Fields

Field	Type	Description
id	string	Logical ID of the resource
meta	Meta	Resource metadata
identifier	Identifier[]	Business identifiers
status	code	Subject status
period	Period	Participation period
study	Reference(ResearchStudy)	Research study
individual	Reference(Patient)	Patient participant
assignedArm	string	Arm subject was assigned to
actualArm	string	Arm subject is actually in
consent	Reference(Consent)	Study consent

Search Parameters

Parameter	Type	Description	Example
_id	token	Resource ID	_id=rsub-001
identifier	token	Business identifier	identifier=SUBJ-1234
patient	reference	Patient reference	patient=Patient/123
individual	reference	Individual reference	individual=Patient/123
status	token	Subject status	status=on-study
study	reference	Study reference	study=ResearchStudy/rs-001
date	date	Participation period	date=ge2024-01-01

Examples

Create a ResearchSubject

curl -X POST http://localhost:8080/baseR4/ResearchSubject \
  -H "Content-Type: application/fhir+json" \
  -d '{
    "resourceType": "ResearchSubject",
    "identifier": [{
      "system": "http://example.org/research-subject-ids",
      "value": "SUBJ-1234"
    }],
    "status": "on-study",
    "period": {
      "start": "2024-06-15"
    },
    "study": {
      "reference": "ResearchStudy/rs-001"
    },
    "individual": {
      "reference": "Patient/patient-001"
    },
    "assignedArm": "Treatment Arm",
    "actualArm": "Treatment Arm",
    "consent": {
      "reference": "Consent/consent-001"
    }
  }'

Create a Withdrawn Subject

curl -X POST http://localhost:8080/baseR4/ResearchSubject \
  -H "Content-Type: application/fhir+json" \
  -d '{
    "resourceType": "ResearchSubject",
    "identifier": [{
      "system": "http://example.org/research-subject-ids",
      "value": "SUBJ-5678"
    }],
    "status": "withdrawn",
    "period": {
      "start": "2024-01-15",
      "end": "2024-04-01"
    },
    "study": {
      "reference": "ResearchStudy/rs-001"
    },
    "individual": {
      "reference": "Patient/patient-002"
    },
    "assignedArm": "Control Arm",
    "actualArm": "Control Arm"
  }'

Search ResearchSubjects

# By patient
curl "http://localhost:8080/baseR4/ResearchSubject?patient=Patient/123"

# By study
curl "http://localhost:8080/baseR4/ResearchSubject?study=ResearchStudy/rs-001"

# By status
curl "http://localhost:8080/baseR4/ResearchSubject?status=on-study"

# Active subjects in a study
curl "http://localhost:8080/baseR4/ResearchSubject?study=ResearchStudy/rs-001&status=on-study"

Patient Compartment

# Get all research participation for a patient
curl "http://localhost:8080/baseR4/Patient/123/ResearchSubject"

Status Codes

Code	Display	Description
candidate	Candidate	Subject is a candidate
eligible	Eligible	Subject is eligible
follow-up	Follow Up	Subject is in follow-up
ineligible	Ineligible	Subject is not eligible
not-registered	Not Registered	Not registered
off-study	Off Study	No longer participating
on-study	On Study	Actively participating
on-study-intervention	On Study Intervention	Receiving intervention
on-study-observation	On Study Observation	Under observation
pending-on-study	Pending On Study	Pending enrollment
potential-candidate	Potential Candidate	May be a candidate
screening	Screening	Being screened
withdrawn	Withdrawn	Subject withdrew

Common Study Arms

Name	Description
Treatment Arm	Receives experimental intervention
Control Arm	Control group (standard care or placebo)
Arm A	First study arm
Arm B	Second study arm
Placebo	Receives placebo
Active Control	Receives active comparator

Usage Notes

Tracking Arm Crossover

When a subject crosses over to a different study arm:

{
  "resourceType": "ResearchSubject",
  "status": "on-study-intervention",
  "assignedArm": "Arm A",
  "actualArm": "Arm B"
}

Subject Lifecycle

1. candidate - Patient identified as potential participant
2. screening - Undergoing screening procedures
3. eligible/ineligible - Eligibility determination
4. pending-on-study - Awaiting enrollment
5. on-study - Enrolled and participating
6. on-study-intervention - Receiving study intervention
7. on-study-observation - Observation phase
8. follow-up - Post-intervention follow-up
9. off-study - Completed participation
10. withdrawn - Subject withdrew from study