Specifies attributes of observation context that may be defined, extended or replaced at any location in the SR tree.
This includes attributes that specify:
who or what the observation is about (“subject context”)
what procedure the observation is about (“procedure context”)
who or what is making the observation (“observer context”)
Establishing context includes two aspects of each dimension: identification and description (e.g. patient name and ID vs. patient’s age, height or weight).
Whenever one dimension of context is changed or an attribute is added, all attributes of that dimension of context are “flushed”, that is they need to be repeated in their entirety. For example, when the subject is changed from patient (name, id) to fetus (number), then the parameters of the patient are discarded. E.g. the patient’s ID does not apply to the fetus.
“Extending” the same class and dimension of observation context isn’t feasible, since one cannot “null out” or remove a previously set attribute. Any time a dimension of observation context is “replaced”, any attributes that are unspecified remain unspecified (i.e. they are not inherited).
TID 1001 OBSERVATION CONTEXT Type: Non-Extensible Order: Significant
|NL||Rel with Parent||VT||Concept Name||VM||Req Type||Condition||Value Set Constraint|
|1||HAS OBS CONTEXT||INCLUDE||DTID (1002) “Observer Context”||1-n||MC||Required if all aspects of observer context are not inherited.||Defaults to the attributes of the Author Observer Sequence (0040,A078), or the Verifying Observer Sequence (0040,A073) if the Author Observer Sequence is not present|
|2||HAS OBS CONTEXT||INCLUDE||DTID (1005) “Procedure Context”||1||MC||Required if all aspects of procedure context are not inherited.|
|3||HAS OBS CONTEXT||INCLUDE||DTID (1006) “Subject Context”||1||MC||Required if all aspects of observation subject context are not inherited.|