ResearchSubject
A patient's enrollment as a clinical-trial subject: participation status, key dates, allocation group, follow-up.
Purpose
ResearchSubject links a Patient to a ResearchStudy, encoding the inclusion lifecycle: screened, eligible, randomized, on-study, off-study, completed. The resource is central to clinical trials for consent management, randomisation (placebo vs treatment arm), drop-outs, and regulatory audit trail (FDA 21 CFR Part 11, ICH-GCP).
Key elements
| Field | Type | Cardinality | Role |
|---|---|---|---|
identifier | Identifier[] | 0..* | External identifiers. |
status | code | 1..1 | Administrative status. |
progress | BackboneElement[] | 0..* | Trial progression (steps, dates). |
period | Period | 0..1 | Participation period. |
study | Reference(ResearchStudy) | 1..1 | Concerned trial. |
subject | Reference(Patient | Group | Specimen | Device | Medication | Substance | BiologicallyDerivedProduct) | 1..1 | Included subject. |
assignedComparisonGroup | id | 0..1 | Allocated arm. |
actualComparisonGroup | id | 0..1 | Actually followed arm. |
consent | Reference(Consent)[] | 0..* | Signed consents. |
JSON example
{
"resourceType": "ResearchSubject",
"id": "example-rs-001",
"identifier": [{
"system": "https://study.example.org/subject-id",
"value": "SUBJ-2026-001"
}],
"status": "active",
"period": {
"start": "2026-05-15"
},
"study": {
"reference": "ResearchStudy/cancer-trial-001"
},
"subject": {
"reference": "Patient/oncology-12345"
},
"assignedComparisonGroup": "arm-treatment",
"actualComparisonGroup": "arm-treatment",
"consent": [{
"reference": "Consent/icf-signed-001"
}]
}Common pitfalls
- ResearchSubject without Consent: ICH-GCP violation, the trial is compromised.
- actualComparisonGroup ≠ assignedComparisonGroup not documented: breaking blinding compromises validity.
- Status 'completed' without Period.end: incomplete audit trail.
Related resources
- researchstudy — clinical trial.
- patient — subject.
- consent — consent.
- group — cohort.