According to a recent report which analyzed mobile app use by the 100 largest hospitals in the U.S.:

• 66% of the 100 largest.hospitals have mobile apps for consumers
• only 2% of patients in those hospitals are using hospital-provided mobile health apps
• about 7% of patients have switched healthcare providers due to a poor experience with online customer services, such as mobile apps and web chat

Source: "U.S. Hospitals Engaging Only 2 Percent of Patients via Mobile Apps, Putting as Much as $100 Million in Annual Revenue [Per Hospital] at Risk, Accenture Finds," Accenture News Release, January 6, 2015, https://newsroom.accenture.com/news/us-hospitals-engaging-only-2-percent-of-patients-via-mobile-apps-putting-as-much-as-100-million-in-annual-revenue-per-hospital-at-risk-accenture-finds.htm