The exchange standards that we’ll be describing come from Health Level Seven International (HL7). HL7 is an international standards organization that exists to develop health data exchange standards.

HL7 is supported by more than 1,600 members from more than 50 countries, including 500+ corporate members representing healthcare providers, government stakeholders, payers, pharmaceutical companies, vendors/suppliers, and consulting firms.

HL7 produces a variety of standards including V2, CDA, and FHIR. We are focusing on HL7 standards but there are other major standards such as DICOM for medical images and NCPDP formulary and benefit standards that are also federally required. You can read more about these standards at HealthIT.gov.

Standards Evolution

The HL7 standards we will be describing (V2, V3 with CDA, and FHIR) have been developed over time, each having been built on the lessons and adopting the useful characteristics of the previous standards. To varying extents, they are all still in use today. We will explore the standards in sequential order, showing how V2, V3, and CDA informed the structure of FHIR, and how FHIR goes further to adopt modern web standards as its basis for exchange.