Using Dates, Times, Timezones and Intervals in NEHTA Clinical Documents

Nov 20, 2012

There’s been a few queries from implementers about the best way to represent dates and times in the NETHA Clinical Documents. It’s not as obvious as it probably should be for several reasons: * Times, timezones, and dates are just hard stuff anyway

  • The flexibility of the underlying v3 types TS, IVL_TS, and GTS means that there’s a lot of possible ways to use the datatypes
  • Actual specific advice in the NEHTA specifications tends be terse and efficient, and also scattered around the different documents
  • Many of the implementations store a full date time in the database, and don’t explicitly track time precision and/or timezone (in fact, many systems are timezone illiterate)

In order to assist implementations, we’ve gathered together a single spreadsheet that summarises the rules that apply to the 5 common clinical documents, and also makes some pragmatic recommendations regarding how to populate these. Because some implementations are waiting for this advice now, and the publication processes take their time, here’s an interim copy of the advice. It’s not final, and I’ll make a note here on the blog when the final version is officially released through the official channels.

DateUsageInCdaDocuments

p.s. thanks to Brett Esler from Oridashi for doing the work on this one.