In previous posts I have stressed the importance of separating content from structure to achieve what is often called content-neutral or content-agnostic behavior. It is important because the structure of various sorts of medical information tends to change slowly or not at all whether it is the outline structure of note, the tabular layout of test results or the fact than any image can be coded as a jpeg or DICOM.
However, a specific piece of information about a particular patient and event is (almost) always different in some way. Therefore, the more the content is separated from the structure, the more stable the entire system will be, both in time and space.
Space refers to gathering information in one place and using it in another. Time refers to gathering information now and using it in either the immediate or remote future. With structure and content separated, systems must be developed with the expectation that the next thing to come down the pipe, whatever it may be, will be different from the last, requiring that it be probed and classified before selecting the appropriate processes to be applied to it. This approach means that changes can be kept confined to adding or altering specific processing modules without requiring that the whole system be altered.
You may recall that have I used an analogy to the postal system to describe this separation of structure from content. Envelopes represent a simple, unchanging structure. The items that you put in the envelope are the content. Except for specific regulatory constraints on size, weight, and hazardous substances, the choice of content is up to you. The recipient will figure out what it is and what to do with it. In any case the envelope doesn't care — it's content-neutral.
So far, believe it or not, we have been discussing theory — part of the theory of medical information. Anyone familiar with the theory can test it or apply it to practically any real-world project. One nice thing about theories is that sometimes they reflect common-sense and people who think about a problem may come to the same conclusion that is embodied in the theory without ever having been aware that there was a theory.
The good news is that a group convened by ONCHIT has been working for about the past year and they have come up with a scheme for achieving interoperability. It's called The Direct Project. There is a video that is worth watching and an article comparing approaches to healthcare information exchange.
The premise of The Direct Project is simple: create a secure, reliable digital envelope into which you can put anything about a patient that you need to send. It can be one or more text files, PDFs, images, HL7 messages, CCR documents, or whatever. They apparently started with no preconceived notions and in about a year got a broad consensus on the goal and the approach, wrote some code, and already used the scheme to send information on real patients to other participants. Could they have shortened the time to completion if they had started with the theory? We'll never know. Maybe they did. One year is pretty good for a committee project either way.
I can hear the cheering section in the background. Go ONCHIT! Go Direct! Go Theory!
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