Is GreenCDA the answer?

Aug 16, 2011

As expected, comments to my previous post are running hot - both public and private. I’ll try and deal with some of them. Firstly, I’m going to deal with the idea that greenCDA is the answer. Robert Worden posted a comment in response to my previous post:

One-size-fits-all semantics is bound to be clunky and will fail the market test. We need clean simple models for sub-domains – DSLs for clinicians – which are precisely linked, probably via the clunky universal model. Green CDA technology now makes this possible

Is this true? Because I don’t think it is. One-size-fits-all applies to HL7 v2, and there’s still an active camp who think v2 is the the answer (yet another post coming up, I guess). One size fits all is a challenge - but the alternative is worse. Quoting from a previous post about compromise:

you can do what HL7 increasingly does: build a complicated framework that allows both solutions to be described within the single paradigm, as if there isn’t actually contention that needs to be resolved, or that this will somehow resolve it. This is expensive – but not valuable; it’s just substituting real progress with the appearance thereof

And this is my core problem with green CDA.

By the way, I like greenCDA. It’s a good idea, a good way to simplify the creation of CDA documents. The problem is, as explained in another previous post of mine about greenCDA, is that you end up trading usability vs reusability:

The more different kinds of CDA you produce (i.e. the more use cases you support), the less useful greenCDA will be, as it will start fractionating your code.

And this is true of a single implementation, or of any community: the more CDA is used, the more greenCDA will start fractionating the community.

I think greenCDA is a good methodology for writing CDA documents. But I don’t think it’s a methodology that offers HL7 a useful path forward for solving our general case.