Family Member History Data Absent Reason

Context and value of Data Absent Reason(s) (DARs) indicating why, for a patient's family history, information is missing or not recorded either about health concern(s) or about the family member having said concern(s).
When a DAR is specified, this class shall be populated, but Family Member History shall not.
Conversely, when an actual family member history record is specified, the Family Member History class shall be populated, but this class shall not.
In this class, 1 of the 2 the DAR Codes - the attributes Reported Family Member Data Absent Reason Code and Health Concern Data Absent Reason Code - must always be populated (but not both).
Optional DAR context is provided by the 2 relationships from this class: to Reported Family Member and to Family History Health Concern.
Use cases as kinds of practitioner-patient dialogue:
(1)
- Practitioner: Is there cancer in you family?
- Patient: Declined to answer.
=>
- relationship to the Family History Health Concern record for cancer with Has Health Concern Indicator = True is populated.
- relationship to Reported Family Member: not populated.
- Reported Family Member DAR Code: not populated.
- Health Concern DAR Code: populated (e.g., asked-declined).

(2)
- Practitioner: Is there cancer in you family?
- Patient: Yes.
- Practitioner: Who in your family has it?
- Patient: Declined to answer.
=>
- relationship to the Family History Health Concern record for cancer with Has Health Concern Indicator = True is populated.
- relationship to Reported Family Member: not populated.
- Reported Family Member DAR Code: populated (e.g., asked-declined).
- Health Concern DAR Code: not populated.

(3) Practitioner: Is there cancer in you family?
- Patient: No.
=>
this class is not populated; instead, the Family Member History class shall contain a record having a relationship to the Family History Health Concern record for cancer with Has Health Concern Indicator = False.