Model 2.0IG 3.4Content 1.0.0Curated educational coverage
DM / special-purpose
Demographics
A subject-level view gives observations a common identity, rather than repeating background attributes in every measurement row.
Start with the participant
Imagine two app databases both assign participant number 001. A stable study-aware identity prevents a join from attaching one person's observations to another. Keep local application keys separate from exported identifiers.
Look inside the structure
7 selected variables. Follow an identifier to its lesson.
Scroll this table horizontally to inspect every field, or read as records.
| Identifier | Domain | Teaching explanation | Example JSON type | Example value |
|---|---|---|---|---|
| STUDYID | DM | The study identifier places this demographics extract in the fictional study CLD-SYN-001. Keep that context when comparing subject records from separate studies. | string | CLD-SYN-001 |
| DOMAIN | DM | The value DM marks the subject-level demographics context in this lesson. It distinguishes the identity record from the participant’s repeated measurements or event records. | string | DM |
| USUBJID | DM | The fictional subject key anchors the demographics lesson. Use it to connect the participant’s background record with observations, rather than joining on the local subject number alone. | string | SYN-001 |
| SUBJID | DM | A local participant label can be meaningful within a study without being globally unique. Preserve it as a string so leading zeros survive export and re-import. | string | 001 |
| AGE | DM | The integer here demonstrates a reported attribute. This lesson does not calculate age from dates or define an age reference point; those decisions require a documented study rule. | number | 34 |
| SEX | DM | This lesson shows where a categorical value might appear. Its sample is null because no verified terminology package is bundled; null is an educational missing value, not an official submission instruction. | null | null (missing) |
| RFSTDTC | DM | A reference date can anchor later time descriptions. Our complete date string illustrates representation only; deciding which event supplies the reference requires the applicable study rules. | string | 2025-01-10 |
See the relationship in an example
Follow the source
Original ClinDevLab explanations. Publisher material is linked, not reproduced. Reviewed 8 October 2026.
- SDTM 2.0https://www.cdisc.org/standards/foundational/sdtm/sdtm-v2-0 · CDISC · 2.0 · accessed 2026-10-08
- SDTMIG 3.4https://www.cdisc.org/standards/foundational/sdtmig/sdtmig-v3-4 · CDISC · 3.4 · accessed 2026-10-08