Please update and use US Core Patient.

If unable to use US Core Patient, please create your own profile, and log a variance request against US Core.

Note from guide:

Observation.subject is restricted to referencing Patient Resource.

Although the US Core Condition, CarePlan, Goal, and Procedure Profiles restrict Subject to US Core Patient Profile, US Core does not offer a generic Observation Profile. For this reason, SDOHCC_Observation_ScreeningResponseBase_1 does not restrict Observation.subject to US Core Patient Profile. However, if an implementer is creating US Core profiles (e.g., US Core Condition, US Core Procedure, etc.) that require US Core Patient for Subject, then US Core Patient should also be used for Subject in other profiles (e.g., Observation, ServiceRequest, etc.) which do not currently specify US Core Patient.