UnitedHealth CEO Andrew Witty said on Thursday that healthcare in the U.S. needs to be "less confusing, less complex and less costly" during the company's first earnings call since the murder of Brian Thompson,

In its first results since its insurance unit CEO was fatally shot in New York City, UnitedHealth Group reported Thursday weaker-than-expected fourth-quarter revenue, prompting its shares to fall in early morning trading despite quarterly profit beating projections.

The CEO of UnitedHealth Group has defended its role in America's health system as the company posted its first earnings results since the murder of one of its top executives. Sir Andrew Witty spoke to analysts as the firm reported mixed results,