## EviPrev Observation profile

## Overview

With the observation the medical data are transmitted to the CDSS. The result returned by the CDSS is also stored in the observations.

The profile is open. All attributes, that are not specified below, are ignored.

Official canonical URL: https://cdss.eviprev.ch/fhir/StructureDefinition/Observation

Resource details: {{link:EviPrevIt/eviprevObservation}}

## Attributes

### Status (status)

Must always be "final".

### Code (code)

The code sescribes the measurement, anamnesis, procedure or CDSS result.

The code specifies the observation type and is a [LOINC](https://search.loinc.org/searchLOINC/search.zul), [SNOMED](http://browser.ihtsdotools.org/?perspective=full&conceptId1=404684003&edition=en-edition&release=v20180131&server=http://browser.ihtsdotools.org/api/v1/snomed&langRefset=900000000000509007) or a custom EviPrev code.
See {{link:EviPrevIt/cdss-input-parameter}} for available codes.

### Subject (subject)

Optional reference to the {{pagelink:EviPrevIt/eviprevpatientprofile}}. The reference is only an addtional information and will not be used.

### Effective Date Time (effectiveDateTime)

Mandatory measurement date.

### Performer (performer)

Optional reference to the practitioner or organization. The references are only addtional information and will not be used.

### Value (value)

The value is mandatory for CDSS inputs. For CDSS result observations there can be no value but dataAbsentReasion will be available in that case.

Following value types are accepted:

* Quantity
{{tree:eviprevObservation-quantity}}
The unit is mandatory and must correspond to a value of [unit of measure coding](https://www.hl7.org/fhir/valueset-ucum-units.html).<br/>
It does not matter which unit is used. The CDSS transforms the value into the desired unit. For example, all units of length can be used for the body size.

* Codeable Concept
{{tree:eviprevObservation-codeableConcept}}
Any code is allowed. The CDSS tries to transform the code in the required value. If the code is invalid, an error would be coded in the dataAbsentReason field of the resulting rule observation.

* String<br/>
Any String is allowed. The CDSS tries to transform the code in the required value.

* Boolean<br/>
For yes/no fields

### Data Absent Reason (dataAbsentReason)

If the CDSS cannot execute a rule because the required parameters are not available or values are outside the valid range, the error codes are displayed here.

### Reference Range (referenceRange)

If a quantity value has been transmitted and the CDSS requires a code, the low and high value range is required for the interpretation.

## Tree

All other fields are for for information only.

{{tree:EviPrevIt/eviprevObservation}}