Re: Why a specifically NHS problem?
It's not specifically the NHS. It's a common problem all over the world. Efforts have been made to break down the barriers. HL7 and as I jokingly referred to in an earlier reply the latest incarnation FIHR. But of course other standards exist because why would you ever need just one?
But this takes time (has taken decades and is still a work in progress).
A lot of it stems from the large sums of money that private companies can get from governments for health care related systems. That makes them reluctant to allow interoperability. Adapting standards like HL7 isn't easy either. Even if you're willing to do it as we were it's a big resource commitment both to implement and then to support. There's enough wiggle room in the standard to mean you're almost forever having to deal with edge cases. That's a lot less common with FHIR since it uses RESTful but HL7 could be a pig and a half when setting up communication between different systems for the first time.