Comment:

Several of the Observation search fields are defined to resolve to two elements – one being on the Observation itself and the other being on a component of the Observation. As a result, users must post-process results to determine if their "code" or "value-[x]" searches matched on the direct Observation or on one of its components.

This can cause further issues when multiple parameters are used. For example a search on "code" and "value-quantity" might contain a result that matches "code" on the Observation but "value-quantity" on one of its components. In this case, "code-value-quantity" might be a better choice, but component parameters don't exist for all possible couplings.

Please support parameters to reference "code" and "value-[x]" of only the observation, as well as parameters to reference "code" and "value-[x]" of only the components.

Summary:

Observation searches that hit two fields are problematic