Michelle Fay Cortez and Caroline Chen, reporting for Bloomberg:

Stanford University researchers were stunned when they awoke Tuesday to find that 11,000 people had signed up for a cardiovascular study using Apple Inc.’s ResearchKit, less than 24 hours after the iPhone tool was introduced.

“To get 10,000 people enrolled in a medical study normally, it would take a year and 50 medical centers around the country,” said Alan Yeung, medical director of Stanford Cardiovascular Health. “That’s the power of the phone.”