We have a use case where a patient reported form for recording information related to bone mineral density scanning, where the patient is asked to record their height “in their youth (about 20 years of age)”.
How should this be recorded?
Our first thought was to use the OBSERVATION.height archetype, with the event point in time set to the patient’s date of birth + 20 years. But this data isn’t really a height recorded at a specific point in time, but at an approximate age which may be 50 years in the past, so back-dating the OBSERVATION feels somehow wrong.
I would suggest to analyse on the basis of what should be returned in querying for patient height. If you expect this estimate (which is not objectively an Observation) to be returned, you could represent it as an Observation with the appropriate timing. If however, you only expect this height (estimate) to be returned in a much narrower query for bone mineral density ‘reports’ or something else that contains the scan result + height estimate - presumably used for estimating degradation of some kind, then the height should be recorded either as an additional data point on the bone density report, or in some related data set that includes it.