Observation Data Absent Reason
Captures the reason the observation values are missing or not recorded for an observation.
In detail:
Specifies context and value of a Data Absent Reason (DAR) indicating why information is missing about some observations on a subject.
When a DAR is specified, this class shall be populated, but Observation shall not.
Conversely, when an actual observation (i.e., with a known value) is specified, the Observation class shall be populated, but this class shall not.
In this class, the DAR code, i.e., the attribute Observation Data Absent Reason Code must always be populated.
If the DAR applies to all observations on the subject, then only the DAR Code is populated. All other attributes, which provide context for the DAR, must be left empty.
If the DAR applies to a specific observation code and/or at a specific observation date and time, then one or both of those context attributes (Observation Code, Observation Date Time) must be populated as well. The DAR Code (e.g., asked-declined) then applies only to a particular observation code and/or at a particular observation date/time.
Appears in
Constraints
Unique key(s)
- XOR (Patient, Party Group, Organization, Location, Standardized Assessment, Device), Observation Code if specified, Observation Date Time if specified
Stereotype(s)
n/a
Attributes
| Attribute | Type | Multiplicity | Attribute note |
|---|---|---|---|
| Observation Date Time | Date Time | 0..1 | The date and time when the observation occurred. |
| Observation Code | Codeable Concept | 0..1 | Uniquely specifies what was observed. Sometimes called "observation name".
Value Set: To be developed. |
| Observation Data Absent Reason Code | Codeable Concept | 1 | Uniquely specifies the reason the observation values are missing or not recorded for an observation.
Value Set: http://terminology.hl7.org/CodeSystem/data-absent-reason |
Relationships
| From class | From multiplicity | Relationship | To class | To multiplicity |
|---|---|---|---|---|
| Observation Data Absent Reason | 0..* | has | Clinical Information Life Cycle Event | 0..* |
| Observation Data Absent Reason | 0..* | for | Location | 0..1 |
| Observation Data Absent Reason | 0..* | for | Device | 0..1 |
| Observation Data Absent Reason | 0..* | for | Standardized Assessment | 0..1 |
| Observation Data Absent Reason | 0..* | for | Patient | 0..1 |
| Observation Data Absent Reason | 0..* | for | Party Group | 0..1 |
| Observation Data Absent Reason | 0..* | for | Organization | 0..1 |
| Observation Data Absent Reason | 0..* | observation performer | Party Role | 0..1 |
Contact us
If you have questions about this initiative, would like to be added to our stakeholder notification list or would like to participate in our consultations, please email us.
How to cite:
Canadian Institute for Health Information. Observation Data Absent Reason. Accessed November 02, 2026.
