HL7 V3, like V2.x, is a standard for exchanging messages among healthcare information systems. However, HL7 V3 is not compatible with V2. V3 defines a more fully-specified data model with less flexibility for customization. This presents a tighter standard that is easier to use, and provides a higher level of formal modeling, complexity, and internal consistency.
HL7 V3 is based on information models, which define the specifications of sets of data that are specific to one area of interest. There are different types of information models, including:
Reference Information Model (RIM) – Defines the information content for a domain.
Domain Information Model (D-MIM) – Defines a set of class clones, attributes, and relationships, and is a subset of the RIM. Domains include the following:
Domains under Administrative Management:
Accounting and Billing
Claims & Reimbursements
Patient Administration
Personnel Management
Scheduling
Domains under Health and Clinical Management:
Clinical Document Architecture
Medical Records
Public Health Reporting
Clinical Genomics
Specimen Domain
Regulated Studies
Refined Message Information Model (R-MIM) – Defines message-specific content, and is a subset of the D-MIM).
The V3 standard also includes interactions, such as Create Patient Billing Account.
There are three modes of Acknowledgement process in HL7 V3:
Immediate Mode
Deferred Mode
Queued Mode