HL7 (Health Level Seven) is a set of international standards for the transfer of clinical and administrative health data between software applications, with HL7 v2 being the most widely implemented healthcare messaging standard and HL7 v3/CDA providing structured clinical document exchange capabilities.
Context for Technology Leaders
For CIOs in healthcare, HL7 standards form the backbone of existing healthcare integration infrastructure. While FHIR represents the strategic direction, HL7 v2 messages are deeply embedded in virtually every healthcare IT system, requiring enterprise architects to maintain expertise in both legacy HL7 and modern FHIR standards during the transition period.
Key Principles
- 1Messaging Standard: HL7 v2 defines message formats and exchange protocols for common healthcare transactions including admissions, discharges, lab results, and pharmacy orders.
- 2Widespread Adoption: HL7 v2 is implemented in virtually every healthcare IT system worldwide, making it the de facto standard for intra-organizational and some inter-organizational health data exchange.
- 3Flexibility and Ambiguity: HL7 v2's flexibility allows extensive customization but creates interoperability challenges as different implementations interpret the standard differently.
- 4Evolution Path: The HL7 standards family has evolved from v2 (messaging) through v3/CDA (documents) to FHIR (APIs), with each generation addressing limitations of its predecessor.
Strategic Implications for CIOs
CIOs should maintain HL7 v2 integration capabilities while progressively adopting FHIR for new integrations and strategically migrating existing interfaces. Enterprise architects should design integration architectures that bridge HL7 v2 and FHIR.
Common Misconception
A common misconception is that HL7 v2 is obsolete and should be immediately replaced. HL7 v2 interfaces are deeply embedded in healthcare operations and will remain in use for many years. Organizations should adopt FHIR for new integrations while managing the gradual transition of existing HL7 v2 interfaces.