Observation - Constraints

Can anyone comment on why effective[x] or issued [x] are considered required? How can there be an observation without any dateTime, unless I am not reading the FHIR specifications correctly.

Any guidance on this is much appreciated

I meant are not considered required

In general, in order to make something required, there have be no use cases where it’s possible for the value not to known. That’s a very high bar to cross. I think that the cases where there’s no time would be very rare.

Also, there are some obsevations for which the time might not be relevant or tracked. If an EHR has a field for the patient’s blood type, they might not bother tracking when that was captured because it doesn’t matter. If they share it, it’ll be exposed as an Observation, but there’d be no meaningful values to put in effective[x] or issued[x]

that makes perfect sense. thank you