HL7 v2: Mechanism and Role in Modern Healthcare, Including Relationship with FHIR
HL7 v2 (HL7 Version 2) - FirestarterPro
Summary
HL7 v2 is a messaging standard that has facilitated data exchange between hospital systems since the late 1980s. It uses a pipe-delimited text format to transmit clinical data—such as admissions or lab results—in near real-time, forming a foundational technology used alongside modern standards like FHIR.
Details
HL7 v2 is a healthcare messaging standard that first appeared in 1987. It was designed to solve the problem of automatically notifying other systems when specific patient events occur (e.g., Admission/ADT, Lab Results/ORU, Orders/ORM). These messages are transmitted over TCP/IP using the MLLP transport protocol and utilize a flat, pipe-delimited text structure consisting of segments and fields. Despite newer standards like FHIR being adopted for patient access APIs and new builds, HL7 v2 remains the dominant real-time messaging standard in internal hospital integrations (e.g., ADT feeds, LIS to EHR). The relationship between v2 and FHIR is complementary: while FHIR handles external API access, v2 manages core internal messaging. Therefore, hybrid architectures that support bidirectional translation between v2 messages and FHIR resources are the industry norm. Understanding HL7 v2 is crucial for anyone working with US hospital data, as lab results, demographics, and orders often arrive downstream via these established v2 interfaces, requiring integration platforms to consume or translate from them.
Original content copyright by respective publishers