PBS Codes in CDA Documents: codeSystemVersion

Jul 27, 2012

Many of the CDA documents that will be part of the overall Australian National Electronic Health Record eco-system include medication information (including dispensing information in some cases). Many of the source systems use PBS codes to represent the medications. For my non-Australian readers, PBS codes are the billing codes for medications used by the national prescribing funding system here in Australia. You can download the definitions here: http://www.pbs.gov.au/browse/downloads.

When represented in a CDA document, a PBS code looks like this:

What to put for codeSystemVersion? The answer is, the date of release (as published at the downloads), in the format YYYYMMDD. As of the today, the release is 1st July 2012, so the codeSystemVersion for this is 20120701. However there’s no need to put the codeSystemVersion in the CDA document - in the long run, it only complicates matters, and the few use cases that it does support are very advanced ones which are beyond current practice here in Australia.

PBS Code Version Management

Several implementers have raised the prospect of PBS re-using old codes. If this were to happen, ongoing use of PBS codes in CDA documents would be unsafe, and there would be no real practical work around that would make them safe. Indeed, PBS has re-used old codes (from before 1987) in the past as a temporary workaround for running out of code space. However the PBS team have advised me that this is no longer acceptable practice, and that when they next run out of codes - estimated to be in Dec 2012/Jan 2012 - then they’ll start using longer codes, and they won’t be re-using old PBS codes any more.