Data Transport Standards (APIs)

The following data transport standards and profiles may be used for each step of the EMS interoperability workflow.

Patient Discovery

IHE Cross-Community Patient Discovery (XCPD)

IHE Cross-Community Patient Discovery (XCPD) is used by health information network to query other networks for patients using known demographic data or identifiers. The responding network returns one or more matches containing patient demographic information and identifiers. Most health information networks today (and all QHINs under TEFCA) use XCPD for network-to-network patient discovery queries. Since it is so widely used between networks, many networks also support XCPD being used by their participants.

• Status: Active
• HL7 versions supported: v3
• Adoption: Widespread via national networks and state/regional health information exchanges

IHE Patient Demographics Query (PDQ)

IHE Patient Demographics Query (PDQ) is used to query a health information network for patients using known demographic data or identifiers. The network returns one or more matches containing patient demographic information and identifiers. Health information networks typically translate PDQ to XCPD if the query needs to be federated to other networks. The are three generations of PDQ: the original PDQ uses HL7 v2; PDQV3 uses HL7 v3; PDQm uses HL7 FHIR. An update to PDQm is underway to add the use of the FHIR $match operation, in which the network will return a single "best match" rather than a list of potentially matching patients.

• Status: Active
• HL7 versions supported: v2, v3, FHIR
• Adoption: PDQ widespread via national networks and state/regional health information exchanges; PDQv3 rare in usage; PDQm available on some networks

Patient Identifier Cross-referencing (PIX)

IHE Patient Identifier Cross-referencing (PIX) is used for cross-referencing of patient identifiers from different sources. A querying system can query a patient identity management system using patient identifiers or demographic information, and the patient identity management system will return a list of other identifiers for that patient from various systems. There are three generations of PIX: the original PIX uses HL7 v2; PIXV3 uses HL7 v3; PIXm uses HL7 FHIR. PIX is unlikely to be needed in EMS workflows.

Patient Master Identity Registry (PMIR)

IHE Patient Master Identity Registry (PMIR) is used for managing information in a master patient index (MPI) using HL7 FHIR. PMIR is unlikely to be needed in EMS workflows.

Patient Medical History to EMS

• To be written

Patient Lookup

• To be written

EMS Patient Care Report to Hospital

• To be written

Hospital Encounter Information to EMS

• To be written

Resources:

• IHE Profiles for Health Information Exchange, by IHE USA