Even if Canada, where the state is effectively the sole insurer and determines treatments and pricing for everyone (arguably more centralized than in the UK), the actors in the healthcare system are still wary of connecting to each other.

I learned about this recently from someone I know who is working in "health informatics" at a hospital. Their systems don't share any data with other hospitals, the ministry (the insurer and regulator), etc. There's an initiative to have hospitals in just a single major urban area connected, and despite it being a few years in only a few hospitals are actually participating.