How should I use organisation information in OpenSafely models?

In customer-facing OpenSafely views, organisation context is exposed in specific models for privacy and governance reasons.

The patient model exposes organisation_id, and sharing_agreement exposes agreement-level requester/sharer organisation metadata.

How to use organisation context safely

Organisation context still matters analytically, but it is represented differently across models.

• patient.organisation_id is a pseudonymised identifier for patient registration context.
• sharing_agreement contains agreement metadata used for access governance.
• Event models are already scoped in the served dataset and can be joined using patient_id.

Do not attempt to re-identify or infer direct equivalence between patient.organisation_id and raw organisation identifiers in agreement metadata.

Recommended join pattern

Use patient_id when joining clinical event models to patient:

SELECT
  o.observation_id,
  o.patient_id,
  p.organisation_id,
  p.sex,
  p.date_of_birth
FROM explorer_open_safely.observation AS o
INNER JOIN explorer_open_safely.patient AS p
  ON o.patient_id = p.patient_id

Practical guidance

• For patient-level joins, use patient_id.
• For organisation-level analysis, use patient.organisation_id.
• For agreement-level analysis, use sharing_agreement fields rather than assuming a shared organisation column across all models.