The notion that British healthcare IT is a model for success is somewhat disputable: http://www.bbc.co.uk/news/uk-politics-24130684

Yes, I know that the gov.uk guidelines are very good, but they relate primarily to customer-facing websites and user-interface design, and don't really cover the gnarly, painful back-end integration jobs. To the extent that healthcare.gov is an expensive failure, it's due to the complexity of the back-end systems and not due to, say, poor UX (although it might have poor UX too).