UnitedHealth Group CEO Andrew Witty testified in Congress in May, after a cyber attack on another of its companies, Change Healthcare, which manages a third of all U.S. patient records, suffered a cyberattack in February that hamstrung large portions of the healthcare system.

The head of US insurance company UnitedHealthcare was shot and killed in what New York City police called a "targeted attack Edited by Caitlin Wilson and Phil McCausland in New York City and Matt Spivey in London The parent company of UnitedHealthcare - where Brian Thompson was CEO - has released a statement saying it is "deeply saddened and shocked at the passing of our dear friend and colleague".