
**Example Usage Scenarios:**

The following are example usage scenarios for this profile:

-  Query for clinical observations or assessments about a patient's health status.
-  [Record or update] clinical observations or assessments about a patient's health status.

### Mandatory and Must Support Data Elements

The following data elements must always be present ([Mandatory] definition) or must be supported if the data is present in the sending system ([Must Support] definition). They are presented below in a simple human-readable explanation. Profile specific guidance and examples are provided as well. The [Formal Views] below provides the formal summary, definitions, and terminology requirements.

**Each Observation Must Have:**

1. a status
1. a category code<sup>1</sup>
2. a code
3. a patient

**Each Observation Must Support:**

2. a time indicating when the observation was made
3. who answered the questions (in other words, a performer)<sup>2</sup>
4. a value

{% include additional-requirements-intro.md type="Observation" %}

1. a screening and assessments category code*
1. references to an associated survey, assessment, or screening tool<sup>3</sup>

<sup>1,2,3</sup> see guidance below

### Profile Specific Implementation Guidance

This section provides detailed implementation guidance for the US Core Profile to support implementation and certification

- The codes can be from LOINC or SNOMED CT.
- The value for these types of observations may be:
  -  a string
  -  a code
  -  a "qualifier" confirming or refuting a statement about findings in code. For example:
      **code**: Transport too expensive (SNOMED CT: 160695008)
      **value**: true

- <sup>1</sup>At a minimum, Certifying Systems **SHALL** support, the [US Core Screening Assessment Observation Category] codes,<sup>[§][CONF-0862]</sup> **SHOULD** support the other [US Core Simple Observation Category] codes,<sup>[§][CONF-0861]</sup> and **MAY** support other categories.<sup>[§][CONF-0863]</sup>

    {% include obs_cat_guidance.md category="sdoh, functional-status, or social history"%}

- See the [Screening and Assessments] guidance page for how this profile can represent "clinical judgments".
  - <sup>3</sup>Observations formally part of an assessment tool or survey **SHOULD** use the [US Core Observation Screening Assessment Profile].<sup>[§][CONF-0441]</sup> However, an assertion or determination derived from screening and assessment tools **SHOULD** reference them using `Observation.derivedFrom`.<sup>[§][CONF-0442]</sup>
{% include provenance-author-bullet-generator.md footnote-symbol='<sup>2</sup>' %}
  -  Although 'Observation.performer' target profiles [US Core Practitioner Profile] and [US Core Patient Profile] are labeled *Must Support*. Servers are not required to support both, but **SHALL** support at least one.<sup>[§][CONF-0868]</sup> Clients **SHALL** support both.<sup>[§][CONF-0869]</sup>
-  <sup>3</sup>Although none of the `Observation.derivedFrom` [referenced target profiles are flagged as *Must Support*](must-support.html#must-support---resource-references), Certifying System **SHALL** support at least one of them.<sup>[§][CONF-0444]</sup> Client Applications **SHALL** support all.<sup>[§][CONF-0849]</sup>
   - As documented [here](general-guidance.html#referencing-us-core-profiles), when using `Observation.derivedFrom` to reference an Observation, the referenced Observation **SHOULD** be a US Core Observation.<sup>[§][CONF-0443]</sup>

{% include link-list.md %}
