The back story (for Denmark) is that we have been building our very own system since the 1990's at massive cost without getting very far, so by now the biggest commercial offering probably looks like a safe heaven.

Reasons the "in-house" systems never got far are a good story. First, there is the normal insanity of hiring consultancies on cost-plus contracts to design and build a system that is "spec'd" by collecting wish lists from everywhere. Despite this, things might have worked: A lot of my friends from uni started work at these consultancies and the story is that there was not much naked greed and cynicism, and that people really tried to come up with good systems. The real killer was that Denmark, despite being a completely homogeneous country of 5m people with state-funded healthcare, did not opt to build a single system!? Healthcare is provided by the "regions", and the regions could not agree on buying a single system. Since Danes expect their medical records available across regions, the ministry of health then had to step in and provide a data interchange standard. Picture an insane XML-schema for every conceivable piece of medical information, coupled with granular access controls and origin metadata. And then mapping this schema faithfully to 5 different alternative representations...