"The system can decide how long to wait before deleting an old session.  The DocumentReference shall be deleted if the QuestionnaireResponse is saved to the EHR and the session finishes."

We need to set some specific expectations here.  The discrete data stored will be needed by the payer when they receive a PDF that refers to the QuestionnaireResponse.  It definitely can't be deleted just when it's persisted on the EHR.  Furthermore, when it's persisted on the EHR, it'll (typically) be persisted as a DocumentReference, not a QR.  (If QR was supported, we'd be storing the intermediate version on the EHR in the first place.)

So - how long after completing the DTR for an order might it take for the claim to come in?  My guess is at least 6 months, maybe as long as 18 months?  (We'll need to work group to decide - and then set that minimum in the spec.)