Appropriate usage of FHIR MedicationRequest paired with MedicationStatement basedOn

I've seen the relationship between a MedicationRequest and MedicationStatement used in different ways at different healthcare entities - specifically linking the two with MedicationStatement.basedOn - and I'm curious if there is a best practice or recommendation for a couple clinical workflows. The FHIR documentation could be interpreted in multiple ways.

Consider the two following basic workflows:

1. A primary care clinic prescribes a non-acute medication (i.e. lisinopril), and creates a MedicationRequest, which gets ePrescribed to a pharmacy. This prescription could be repeatedly refilled and remain active for the patient's life, or could be stopped if the patient no longer needs later in time. This prescription will span multiple encounters (events) for the treatment plan for this patient.
2. A patient arrives for an inpatient stay at a hospital. That patient notes they take lisinopril during their intake, and the hospital stores this as a MedicationStatement. That patient's primary care physician (who prescribed the lisinopril) and the hospital are hooked up to the same HIE, and the hospital sees the MedicationRequest for that patient when ingesting data.

For scenario 2 (more straightforward), I could see the hospital setting a reference on their MedicationStatement.basedOn to the ingested MedicationRequest. This aligns with the following from the MedicationStatement documentation:

This is a record of a medication being taken by a patient or that a medication has been given to a patient, where the record is the result of a report from the patient or another clinician, or derived from supporting information (for example, Claim, Observation or MedicationRequest). A medication statement is not a part of the prescribe->dispense->administer sequence but is a report that such a sequence (or at least a part of it) did take place, resulting in a belief that the patient has received a particular medication.

This resource is distinct from MedicationRequest, MedicationDispense and MedicationAdministration. Each of those resources refers to specific events - an individual order, an individual provisioning of medication or an individual dosing. MedicationStatement is a broader assertion covering a wider timespan and is independent of specific events. The existence of resource instances of any of the preceding three types may be used to infer a medication statement. However, medication statements can also be captured on the basis of other information, including an assertion by the patient or a care-giver, the results of a lab test, etc.

For scenario 1 however, I have seen two possible ways to use these resources based on the above. Depending on how the above is interpreted, both could be argued as appropriate usage:

1. When the clinic prescribes lisinopril, a MedicationRequest is created. If treatment is stopped, that resource's status is updated. MedicationStatement resources are reserved for when their patients self-report a medication, or from ingesting data from a HIE.
2. When the clinic prescribes lisinopril, both a MedicationRequest and MedicationStatement is created. The MedicationRequest only refers to that specific encounter of prescribing the medication, and the MedicationStatement is used throughout the overall treatment of the patient, spanning multiple encounters or events. If the treatment no longer requires lisinopril, the MedicationStatement status is updated.

From a purely technical perspective, both are using the resources correctly (MedicationStatement is basedOn the MedicationRequest). However from a FHIR usage and clinical data perspective, which usage is correct?

MedicationStatement.basedOn has been dropped in R5 and shouldn't really be there in R4. It would mean "This MedicationStatement was created under the authorization of order XYZ", and that almost never makes sense. If you're going to link a statement to an order, use the 'derivedFrom' element.

Both scenarios are fine. MedicationStatement can be used just for self-reported meds, but it's also fine to have an instance for each active medication therapy. It sort of depends on how the system likes to represent information.