Thinking Ahead

A very long time ago, when I worked at Florida State University, I had two rules for programming written on my board:

1. Just get it to work.
2. If it works, don't mess with it.

It became a test of the quality of people who would read it, as the ones who suffered from some sort of reaction while interpreting the ramifications were definitely the people that I wanted to have around me.

If you just get it to work, and don't mess with it, you have something that has the very least effort put into it.  If you need to change it in the future, good luck with that.

Along the same lines, when I was growing up, a kid who lived on my street had a small car, I think it was a Dodge of some sort, and he wanted to beef it up. So he took out the engine and tranny, and replaced it with a MUCH bigger one.  Somehow he managed to make it all fit together after modifying the drive shaft, but he forgot one very important thing: Engine torque.  When he finally started the car after spending the better part of a year on this project, he wound up warping the frame, something like the picture to the right.  The car was a total loss.  The point of this story is that you can only do so much with a limited infrastructure.

One of the challenges with FHIR adoption for some use cases is that there are existing HL7 interfaces, labs, ADT feeds, immunizations, et cetera, that are already widely deployed, adopted, and working, in fact, working well.  There's little desire to replace these interfaces with FHIR based interfaces because:

1. What we have is good enough for what we are doing.
2. It's working right now.

But as we keep pushing the interoperability needle higher and higher, eventually we will have replace these interfaces. When should we do that?

1. When what we have isn't good enough for what we want to do.
2. Or we can't make want we want to do easily work with what we have right now.

The HL7 V2 to FHIR project is an example of what happens when interfaces get stuck in these situations, we cannot easily connect them to newer infrastructure so that we can do more with them, so we build things that enable us to convert from one to the other.  The very existence of the project demonstrates that there's more than we want to be able to with the data present in HL7 Version 2 messages.  This might include things like:

• Aggregating data from multiple sources
• Providing more sophisticated searching capabilities
• Enabling data subscriptions

There's a lot of effort and cost associated with replacing something that works with something else, and it's hard to justify that when the thing that's working is in fact still working.  But, if there was a way to upgrade, replacing your scooter with a Corvette (and you can justify the need for a Corvette), then it might in fact be worthwhile.

When interface standards are mandated by regulatory policy, it's pretty difficult to upgrade.  Consider what happened with X12 5010 standards, or the whole discussion around CCDA 1.1 and CCDA 2.1 backwards compatibility.  It's even more difficult when it all has to happen in a very short time frame.  We need to consider how to have policy enable these kinds of shifts, over REASONABLE time frames.  Two years is not enough time to roll out a new standard without severely impacting an industries capacity to do anything else but roll that out.  We know that from experience (or at least I hope we do).

But what would the next generation ADT, lab, immunization or other standards look like?  And what would they enable us to do that the current ones don't.  It's time to start thinking about that.