[FOSS_health] my summary of discussion

[David Forslund]

Some comments below:

Lee Seldon wrote:
> This morning I finally gave up and decided to make a digest of the 
> discussion. So I have pasted together what I find interesting pieces. 
> I still need time to study this and follow up on many of the points.
> A very very short summary:
>  - FOSS should probably aim for 'functional' interoperability, but 
> might have to start with a 'basic' one.
>  - communications should be based on XML, not on HL7 v2.x.
I'm not sure what the above means.  These two things aren't an either or 
and I think of those as data representations with transport being 
orthogonal to both.  That is there are many ways to transport an XML 
representation of data and there are many ways to transport an HL7 data 
model. 
>  - using XML there already seem to be several (compatible?) 
> initiatives. However, VistA and openMRS both use HL7 v2.x, obviously 
> for reasons of interoperability with existing applications (including 
> themselves).
>  - middleware approaches (CORBAmed, gateways, hubs) have been 
> successful, but seem to have gotten lost or lost favor like much other 
> stuff (good and bad) in IT. Reviving one of them might be more effort 
> than just letting it rest in peace.
I don't know what "reviving" means.  They work and there are working 
examples that utilize XML.   You do need some time of "middleware" even 
if it is "http" or HL7 messages  There is the many-to-many problem 
connectivity problem, regardless.  If you only want to do point-to-point 
(P2P), then the problem is simpler, but this frequently doesn't involve 
much in the way of interoperability. 
>  - the next step could be to agree on an existing XML-based standard, 
> e.g. CCR, HL7 v3 CDA, HL7 v3 messages (of which there exists an 
> extensive list), etc, or join an existing interoperability project, 
> e.g. HSSP HDTF, ... (I am not familiar with these, but somebody 
> certainly is). I can give my opinion of the CCR, HL7 v3, etc ones if 
> desired.
One can use CCR with a transport layer.  We have an example that shows 
CCR working within the COAS model.  CCR isn't "free", however.  We have 
an implementation that supports it, but the XSD file for CCR costs 
money.  Same for CDA or HL7. 

So I think one should consider the two factors of interoperability and 
think of them somewhat separately.  One is the data or information 
model; the other is the communication or transport model.  This is 
discussed in considerable detail in the COAS specification and is 
helpful in other contexts, too. Frequently, people combine these but 
that can confuse the discussion, in my opinion.

Dave
> Lee
>