HL7v3 CDA - Information that does not fall under established field

Question

New to HL7, so my apologies and thanks upfront.

What is the procedure for storing data in HL7v3 CDAs that does not fall under the purview of a field in the standard?

For example, I'm trying to store information about Personal Protective Equipment (PPE) worn by the patient and its status during an encounter. I'm specifically trying to contain information about eyewear, helmets, flak jackets, etc.

Is there a 'junk drawer' field that could be co-opted for this purpose? I know that the whole point of v3 is to standardize data forms and impose rigors, but there must be an option for data not encompassed under the current options.

Answer 1

You can extend CDA by adding elements in a different namespace. Note, though, that a lot of implementations don't support this.

An alternative option is to use 'observation'- we observed that the patient was wearing this particular PPE at this time.

Answer 2

As Grahame expose, you can add elements in a different namespace, but it is not recomended, as that would just be valid for you. I recommend that you use the two existing generic elements: 1- Participant/AssociatedEntity at header level 2- Section/Entry/Act at body level.

Answer 3

I bet you are using one of those CDA document level templates, likely CCD. It lists required section level templates and allows you to add your custom section level templates. As such, you may build your own section level templates specific to wearable devices. Check C-CDA R2 Self-Care Activities or Medical Equipment Section section level templates as possible starting points.

Also, all of the existing sections are open sections meaning you can extend them. However, the recipient of the CDA document is not required to understand the complete set of CDA entries you submit.

Also note, that the Observation.value class attribute is type of ANY which means you may use collection data types, and provide detailed description in the section's narrative block.