HL7v2
Health Level Seven version 2, a pipe-delimited messaging standard for exchanging clinical data between healthcare systems.
HL7v2 has been the dominant integration standard in healthcare since the early 1990s. Messages use a pipe-delimited format with segments like MSH (message header), PID (patient identification), and OBX (observation result). Despite being decades old, HL7v2 still carries the majority of hospital interface traffic today. Common message types include ADT (admit/discharge/transfer), ORM (orders), ORU (results), and MDM (medical documents).
FAQ
- Is HL7v2 still used in 2024?
- Yes. Most hospital interfaces still run on HL7v2. FHIR adoption is growing but HL7v2 remains the workhorse for real-time clinical messaging.
- What is the difference between HL7v2 and FHIR?
- HL7v2 uses pipe-delimited text messages sent point-to-point. FHIR uses JSON/XML resources over RESTful APIs. HL7v2 is event-driven; FHIR supports both push and pull patterns.