This code system http://terminology.hl7.org/CodeSystem/data-absent-reason defines the following codes: Lvl Code Display Definition Comments 1 unknown Unknown The value is expected to exist but is not known. 2 asked-unknown Asked But Unknown The source was asked but does not know the value. 2 temp-unknown Temporarily Unknown There is reason to expect (from the workflow) that the value may become known. 2 not-asked Not Asked The workflow didn't lead to this value being known. 2 asked-declined Asked But Declined The source was asked but declined to answer. 1 masked Masked The information is not available due to security, privacy or related reasons. Using "masked" may be breach of security or confidentiality, but there are times when its use is required to support alternate workflows for gaining access to denied information. 1 not-applicable Not Applicable There is no proper value for this element (e.g. last menstrual period for a male). 1 unsupported Unsupported The source system wasn't capable of supporting this element. 1 as-text As Text The content of the data is represented in the resource narrative. It may be linked by internal references (e.g. xml:id). This usually implies that the value could not be represented in the correct format - this may be due to system limitations, or this particular data value. 1 error Error Some system or workflow process error means that the information is not available. 2 not-a-number Not a Number (NaN) The numeric value is undefined or unrepresentable due to a floating point processing error. This is sometimes an output value from measuring devices. 2 negative-infinity Negative Infinity (NINF) The numeric value is excessively low and unrepresentable due to a floating point processing error. This is sometimes an output value from measuring devices. 2 positive-infinity Positive Infinity (PINF) The numeric value is excessively high and unrepresentable due to a floating point processing error. This is sometimes an output value from measuring devices. 1 not-performed Not Performed The value is not available because the observation procedure (test, etc.) was not performed. 1 not-permitted Not Permitted The value is not permitted in this context (e.g. due to profiles, or the base data types). This is most often associated with required bindings that do not include the actual code used, but may be used with other data types.
Used to specify why the normally expected content of the data element is missing.
The value is expected to exist but is not known.
The source was asked but does not know the value.
There is reason to expect (from the workflow) that the value may become known.
The workflow didn't lead to this value being known.
The source was asked but declined to answer.
The information is not available due to security, privacy or related reasons.
There is no proper value for this element (e.g. last menstrual period for a male).
The source system wasn't capable of supporting this element.
The content of the data is represented in the resource narrative.
Some system or workflow process error means that the information is not available.
The numeric value is undefined or unrepresentable due to a floating point processing error.
The numeric value is excessively low and unrepresentable due to a floating point processing error.
The numeric value is excessively high and unrepresentable due to a floating point processing error.
The value is not available because the observation procedure (test, etc.) was not performed.
The value is not permitted in this context (e.g. due to profiles, or the base data types).