[ef4]

It's true that the patient records use disparate standards, and that it's not trivial to convert them. But even when you have systems that adhere to the various existing data exchange standards, there are deeper structural reasons that organizations are hesitant to exchange data.

Their existing software often does a bad job of identifying the provenance of information or filtering out noisy irrelevant information, so unless they can be assured that everyone else is following the same policies around how things are documented and categorized, they're unwilling to mix a bunch of "outside" data with their own.

They also see little incentive to invest effort in opening up their own data to others, because it costs real money and doesn't really benefit them. This is where a good startup business could make a difference -- by doing the data exporting work "for free" in exchange for the ability to sell access to it.