What I'd like to expand upon now is an issue that could occur if C-CDA Release 2.0 was adopted as optional criteria for 2015 and how we could arrange things so that a 2014 system could receive it. It draws in part on what I described previously as a Dual Compatible CCD, but is slightly different because CCDA 2.0 is largely backwards compatible with CCDA 1.1.
The issue is that when System N (for new) sends a CCDA 2.0 document to System O (for old) that understands CCDA 1.1 there are three things that could happen:
- System O would correctly identify the fact that the CCDA 2.0 document did NOT comply with CCDA 1.1 and would reject it.
- System O would NOT correctly identify this fact because the template identifiers are similar enough, and some don't understand the details of how to match identifier values in HL7 Version 3 and CDA, and so it would incorrectly try to process it. System O would handle these as follows:
- Where these templates are backwards compatible:, System O would handle the 2.0 templates correctly where they are backwards compatible with 1.1, BUT,
- Where they are not, System O would have issues with interpretation of the content.