| Name | Flags | Card. | Type | Description & Constraints |
|---|---|---|---|---|
  ResearchSubject | TU | DomainResource | Physical entity which is the primary unit of interest in the study Elements defined in Ancestors: id, meta, implicitRules, language, text, contained, extension, modifierExtension | |
  identifier | Σ | 0..* | Identifier | Business Identifier for research subject in a study |
 status | ?!Σ | 1..1 | code | draft | active | retired | unknown PublicationStatus (Required) |
 progress | 0..* | BackboneElement | Subject status | |
 type | 0..1 | CodeableConcept | state | milestone ResearchSubjectStateType (Example) | |
| subjectState | 0..1 | CodeableConcept | candidate | eligible | follow-up | ineligible | not-registered | off-study | on-study | on-study-intervention | on-study-observation | pending-on-study | potential-candidate | screening | withdrawn ResearchSubjectState (Required) | |
| milestone | 0..1 | CodeableConcept | SignedUp | Screened | Randomized ResearchSubjectMilestone (Example) | |
| reason | 0..1 | CodeableConcept | State change reason StateChangeReason (Example) | |
| startDate | 0..1 | dateTime | State change date | |
 endDate | 0..1 | dateTime | State change date | |
| period | Σ | 0..1 | Period | Start and end of participation |
 study | Σ | 1..1 | Reference(ResearchStudy) | Study subject is part of |
| subject | Σ | 1..1 | Reference(Patient | Group | Specimen | Device | Medication | Substance | BiologicallyDerivedProduct) | Who or what is part of study |
| assignedArm | 0..1 | string | What path should be followed | |
| actualArm | 0..1 | string | What path was followed | |
| consent | 0..1 | Reference(Consent) | Agreement to participate in study | |
| Documentation for this format | ||||