## SMIS Observation

### Table of Contents

1. [SMIS Resources](#smis-resources)
2. [Profiles](#profiles)
3. [Interactions](#interactions)
4. [Observation Identifiers](#observation-identifiers)
5. [Observation Fields](#observation-fields)
6. [Related Vital Signs Observation Fields](#related-vital-signs-observation-fields)

### SMIS Resources

Following SMIS resources are represented in FHIR as observations.

| Name | Category (system#code) | Code (system#code) |
|--------------------------|----------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------|
| Nursing report | [http://smis.ch/fhir/CodeSystem/smis-observation-category-code#open-type](https://simplifier.net/SMIS/smis-observation-category-codes) | [http://smis.ch/fhir/types/open#nursing-report](/SMIS/smis-types) |
| Unstructured vital signs | [http://smis.ch/fhir/CodeSystem/smis-observation-category-code#open-type](https://simplifier.net/SMIS/smis-observation-category-codes) | [http://smis.ch/fhir/types/open#vital-signs](/SMIS/smis-types) |
| Structured vital signs | [http://hl7.org/fhir/observation-category#vital-signs](http://hl7.org/fhir/STU3/codesystem-observation-category.html) | [http://loinc.org#85353-1](http://details.loinc.org/LOINC/85353-1.html) |

### Profiles

* Default: {{pagelink:SMIS/SMISObservationProfile}}
* Related: {{pagelink:SMIS/SMISRelatedObservationProfile}}
* Vital signs: {{pagelink:coreprofilesstu3/vitalsigns}}

{{tree:SMIS/Observation}}

The subject may be a reference to a patient by internal SMIS id

```json
"subject": {
  "reference": "Patient/1489161154728048"
}
```

or an identifier identifying the patient with the external id.

```json
"subject": {
  "identifier": {
    "system": "http://smis.ch/fhir/patient/external_id",
    "value": "FDDEC0EA-A0FA-448C-916E-51C777AD97E8"
  }
}
```

### Interactions

* update
* create
* search by patient and category
  * Search parameters:
    * patient (required)
    * category (required)
* Search by patient and identifier
  * Search parameters:
    * patient (required)
    * identifier (required)

It's possible to search for a resource by internal or external patient id:

```
GET /fhir/MedicationStatement?patient=1489161154728048
GET /fhir/MedicationStatement?patient.identifier=FDDEC0EA-A0FA-448C-916E-51C777AD97E8
```

### Observation Identifiers

| Name | System | Sample Value |
|-------------------------|-----------------------------------------|------------------|
| Internal Element Id | http://smis.ch/fhir/element/internal_id | 1297774007642120 |
| External Element Id | http://smis.ch/fhir/element/external_id | 304C24D6-007B-465D-B608-26DCC3DA63AF |


### Observation Fields

The observation profile is open. Therefore, all attributes of the base observation are allowed. SMIS only needs the following attributes, all others are ignored.

| Path | Comment |
|------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------|
| id | Numeric SMIS id |
| identifier[system=http://smis.ch/fhir/element/external_id] | Required |
| category.coding[1].system | ["http://smis.ch/fhir/CodeSystem/smis-observation-category-codes", "http://hl7.org/fhir/observation-category"] |
| category.coding[1].code | ["open-type", "vital-signs"] |
| code.coding[1].system | ["http://smis.ch/fhir/types/open", "http://loinc.org"] |
| code.coding[1].code | ["vital-signs", "nursing-report", "85353-"] |
| subject.reference | Required if subject.identifier is empty. Numeric ID |
| subject.identifier.system | Required if subject.reference is empty. Fixed: http://smis.ch/fhir/patient/external_id |
| subject.identifier.value | Required if subject.reference is empty. External patient id |
| effective | Required |
| status | final |
| value | Required if category is 'open-type'  |
| related | Required if category is 'vital-signs' |

### Related Vital Signs Observation Fields

| Path | Comment |
|---------------------------|---------------------------------------------------------------------------|
| category.coding[1].system | http://hl7.org/fhir/observation-category |
| category.coding[1].code | vital-signs |
| code.coding[1].system | http://loinc.org |
| code.coding[1].code | One of https://www.hl7.org/fhir/valueset-observation-vitalsignresult.html |
| status | final |
| valueQuantity.value | Required |
| valueQuantity.system | http://unitsofmeasure.org |
| valueQuantity.code | Required |