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HL7 Version 3.0

Since 1997, the HL7 organization has been developing version 3.0 of the protocol. Unlike 2.X versions, HL7 3.0 is based largely on a single formal model called the Reference Information Model, or RIM for short. The goal of RIM is to reduce the implementation costs of HL7-enabled solutions and further standardize the HL7 communication specifications between healthcare systems.

HL7 3.0 is a complete redefinition of the HL7 standard that is intended to try and overcome some of the issues with the current standard. Version 3 will change not only the content of the messages and fields, but also the encoding rules, LLP (low level communication protocols), base data types and even the roles of the applications participating in HL7 communications. XML is the planned medium for HL7 interchange instead of the simple ASCII text that is currently in use.

Since HL7 3.0 is based largely on one model using a consistent methodology it should be less ambiguous, making it easier to implement in the future. This should also make updates to the standard more simple, largely due to its improved development methodology.

Although version 3.0 is said to be the standard of the future, its shortcomings should not go unmentioned, especially when comparing it to current 2.X standards. For example, version 3.0 has been in development since 1997. That is ten years after the start of development, with no clearly-defined resolution in sight. In addition, because the standard is not "official", there is a shortage of healthcare facilities (labs, hospitals, etc.) that want to be the first ones to migrate to version 3.0. After all, interfacing between version 2.X and 3.0 is currently impossible, as HL7 3.0 offers no compatibility with version 2 standards. As a result, healthcare applications will need to support both version 2.X and 3 in the foreseeable future.

In comparison to version 3.0, 2.X versions offer many current advantages. For instance, version 2.X of the standard is still widely used and implemented in various healthcare facilities worldwide. Moreover, since the version 2 standards were designed with backward compatibility in mind, interoperability across existing healthcare applications that utilize different versions is relatively simple. Furthermore, although version 2 standards were not initially designed to work with XML, there are HL7 specifications available that make this possible.

All in all, although the healthcare industry will eventually move towards the adoption of HL7 3.0 in the future, the widespread use of version 2.X continues to grow and remains the popular choice among healthcare facilities and vendors alike.

For more information about HL7 Version 3.0, see HL7 Version 3.0 Resources.