The HL7 Reference Information Model (RIM) represents a static model of healthcare workflows as viewed by the HL7 standards development group. The RIM is the ultimate source from which all HL7 V3 standards draw their information-related content. Its structure is both flexible and extensible, and it can be readily mapped to the HL7 2.x message standard and other healthcare dataset specifications.
Development of the HL7 RIM began in 1996, and the first draft release of the RIM was released by HL7 in January 1997. Over the next four years, the RIM was continuously harmonized with the release of version 1.0 of the RIM in January 2001. The basis for the Normative Edition of the RIM was then released in 2005.
The harmonization of the RIM was focused on five major themes:
- Ensure coverage of HL7 version 2.x. Ensured that it included all the information content of HL7 version 2.x.
- Remove unsubstantiated content from the model. Removed content from the draft that the technical committee did not originate and could find no rationale for retaining.
- Unified service action model (USAM). Introduced a concise, well-defined set of structures and vocabularies that address the information needs of a wide variety of clinical scenarios.
- Ensure quality. Addressed inconsistencies in the draft model and conflicts between the model and the modeling style guide.
- Address the “left-hand side” of the model. Introduced powerful structures and vocabularies for the non-clinical portions of the model (patient administration, finance, scheduling).
The HL7 V3 standard is a model-driven methodology in which a network of inter-related models depict the static and behavioral aspects of the requirements of HL7 standards. The models also define the underlying semantics and business rules. The RIM is the root of all information models and structures developed as part of the V3 development process.
The HL7 V3 standard was slow to be accepted in the United States. However, it did see some adoption internationally. A subset of the V3 standard did receive a boost in attention in 2010 when the ONC included the CCD document as a standard in its Final Rule for EHR Certification. The CCD document is based on the V3 standard.