US HITSP: T23: HITSP Patient Demographics Transaction. The Patient Demographics Query Transaction is intended to provide a ‘list patients and their demographics’ query / ‘patient(s) and their demographics identified’ response message pair (QBP^Q22, RSP^K22) for use wherever such needs exist. This Transaction document extracts the Health Level Seven (HL7) version 2.5 Query and Response data mapping. The underlying basis for this extraction can be found in the Integrating the Healthcare Enterprise IT Infrastructure Technical Framework, Patient Demographics Query integration profile.