Creating all electronic health records—the centrepiece of the £12bn (€15bn; $23bn) scheme to computerise the NHS in England—has been a challenge “far greater than expected,” the latest study of the world’s largest civil information technology programme reported last week.

In its second study of the National Programme for IT in the NHS, the National Audit Office concluded that software procured to create detailed electronic health records in secondary care may not be available until 2015, five years behind schedule.

The prediction will provide ammunition to critics calling for changes to the …