THE APP WILL SEE YOU NOW:

A smartphone app that launches this week gives the health insurance company Aetna access to detailed user health-tracking data. As costs spiral upward, health-care companies could turn to such apps as a way to monitor customers and encourage healthy behavior. [...]

Nearly 50,000 health-related mobile apps are already out there, letting people collect data about their well-being and interact with doctors and pharmacies from their mobile devices.

With the entire U.S. health-care system under pressure to reduce costs, insurance companies could start creating financial incentives for people to voluntarily share this data and improve their health and fitness.

President Obama's Affordable Care Act, Wofford says, allows insurers to increase so-called "wellness incentives" to up to 30 percent of a premium, up from 20 percent before. This would allow employer health plans to create bigger "carrots" for their employees to go to the gym or use a Fitbit. Under U.S. law, incentives have to be based on behaviors--say, joining a gym--rather than outcomes, such as losing 10 pounds versus two pounds, Wofford says. The same rules do not apply in Europe.

CarePass will be offered to individuals at first, but Aetna plans to launch a portal for employers, too. There they will receive anonymous and aggregated data about the overall health trends of their employees, Wofford says.

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