Among the ICO’s findings were that patients were not adequately informed that their data would be used as part of the test, which was a trial in alert, diagnosis and detection for acute kidney injury. The trust gave persona data for about 1.6m patients.

Elizabeth Denham, Information Commissioner, said: "There’s no doubt the huge potential that creative use of data could have on patient care and clinical improvements, but the price of innovation does not need to be the erosion of fundamental privacy rights. "

She said there had been a number of shortcomings in the way patient records were shared and the ICO has requested a number of changes.

Denham subsequently wrote a blog with four pointers for NHS trusts to comply with data protection.