Pull latest vital signs from Observation

[Evelyn]

Hi,

I am trying to pull the latest vital for a patient. After I do a vital search via /Observation?patient=<patient id>&category=vital-signs, what's the best way to get the latest vitals by looping through the resources? Should we compare the lastUpdated timestamp or is there a convenient way? 

Thanks,

[Aaron McGinn (Cerner)]

It may depend on what your workflow needs. From our documentation [1]:

• Results are sorted by effective date/time in descending order by page. That is, all Observations on any given page of results are newer than all Observations on the next page of results. Sort order within pages is not guaranteed.
• If the query uses the _lastUpdated query parameter, results are sorted by last updated date/time in descending order by page, not by effective date/time.

[1] https://fhir.cerner.com/millennium/r4/diagnostic/observation/#search

-Aaron (Cerner)