> ## Documentation Index
> Fetch the complete documentation index at: https://docs.metriport.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Observation

> Schema documentation for the Observation table in the Metriport data model

The observation resource is used to support diagnosis, monitor progress, determine baselines and patterns and even capture demographic characteristics.

**Reference Table:**

The `observation_references` table contains normalized references from the observation to other entities. It supports the following reference properties:

* **subject** (required): links to the patient who is the subject of the observation
* **encounter**: links to the encounter where the observation was made
* **performer**: links to practitioners who performed the observation

For detailed information about reference table structure and indexing, see the [Reference Tables documentation](/medical-api/handling-data/schema-v000/reference-tables).

**Observation Table:**

**Primary Keys:**

* observation\_id

**Foreign Keys:**

* patient\_id

| Column                        | Data Type | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| ----------------------------- | --------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| observation\_id               | varchar   | Unique identifier for the observation                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| patient\_id                   | varchar   | Unique identifier for the patient                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| status                        | varchar   | Status of the observation. Possible values:<br />– <code>registered</code>: The existence of the observation is registered, but there is no result yet available.<br />– <code>preliminary</code>: This is an initial or interim observation: data may be incomplete or unverified.<br />– <code>final</code>: The observation is complete and verified by an authorized person.<br />– <code>amended</code>: Subsequent to being final, the observation has been modified; the current version is complete and verified.<br />– <code>corrected</code>: Subsequent to being final, the observation has been modified to correct an error in the result.<br />– <code>cancelled</code>: The observation is unavailable because the measurement was not started or not completed.<br />– <code>entered-in-error</code>: The observation has been withdrawn following erroneous entry.<br />– <code>unknown</code>: The authoring/source system does not know the current status of the observation. |
| effective\_date               | date      | Start date of the observation                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| end\_date                     | date      | End date of the observation                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| loinc\_code                   | varchar   | LOINC code for the observation                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
| loinc\_display                | varchar   | Human-readable description of LOINC code                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| source\_code\_code            | varchar   | Original code from source system                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
| source\_code\_display         | varchar   | Original code display from source system                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| source\_code\_system          | varchar   | Original code system from source system                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| value                         | varchar   | Value of the observation                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| units                         | varchar   | Unit of measurement                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| reference\_range\_low         | varchar   | Lower bound of the reference range                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| reference\_range\_high        | varchar   | Upper bound of the reference range                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| category\_hl7\_code           | varchar   | HL7 category code                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| category\_hl7\_display        | varchar   | Human-readable description of HL7 category                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| interpretation\_hl7\_code     | varchar   | HL7 interpretation code                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| interpretation\_hl7\_display  | varchar   | Human-readable description of HL7 interpretation                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
| bodysite\_snomed\_ct\_code    | varchar   | SNOMED CT body site code                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| bodysite\_snomed\_ct\_display | varchar   | Human-readable description of SNOMED CT body site                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| note\_text                    | varchar   | Additional notes about the observation                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| meta\_source                  | varchar   | Source document filename from FHIR meta.source                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
| data\_source                  | varchar   | **Deprecated.** Use `meta_source` instead.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| data\_source\_ext             | varchar   | Integration source of the data, derived from FHIR extension                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |