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How the Big Data Revolution in Healthcare Is Putting Patients in Charge

Clifton Leaf

“If we assume that everybody sleeps 7½ hours a night,” begins Aetna CEO Mark Bertolini, “then we have just over 6,000 waking hours a year.” Out of that total, the average American spends only 20 hours in the health care system, he says. “So 99.7% of the time that we’re living our lives and being impacted by the world,” we’re not in a doctor’s office, clinic, or hospital. And yet, says Bertolini, it’s this overwhelming share of our time—that happy-go-lucky 99.7%—that the current overpriced, underperforming U.S. health care system doesn’t begin to address.

And that’s the problem, Bertolini says.

Bertolini, it’s worth noting, is one of this broken health care system’s most successful CEOs. (Since he took the reins, Aetna aet has returned a cumulative 541% to its shareholders, or more than three times the total return for the S&P 500.) And he’s a captivating storyteller as well. If you get the chance, have him tell you about that time, in 2004, when he was skiing in Vermont with his daughter, caught the edge of a tree, and woke up from a coma six days later.

But mostly, he’s a big thinker—and he has spent the past several years thinking about what’s wrong with our current model of health care.

“As we talk to more and more people about health,” he says, “the way they define it is ‘something that either facilitates or creates barriers for me in living the life I want to lead.’ ” When Bertolini began to frame health in those terms, he tells me, he began to see Aetna’s “journey” more clearly—understanding that it needed to transform from a company that “sells insurance in a warranty card” to one that says to its customers, “Let’s figure out what’s standing in the way of living the life you want to lead. Then we can build alternatives for you.”

And, importantly, most of that “standing in the way” stuff happens during the 99.7% portion of our lives away from the doc.

That revelation was what threw Aetna into the arms of CVS cvs , says Bertolini, whose vision is to create a “cloud-based technology platform that connects a community of health providers to the local community in their daily lives,” and makes the contacts between them easier and less costly.

If all that sounds kind of gooey, well, that’s truly the broader mission of the digital health wave too—a movement that attracted a record $5.8 billion in venture funding last year, according to Rock Health. This quest has captivated not only traditional players like Aetna and CVS, but also virtually every major tech company around, including Apple, Alphabet, and Amazon.

What’s making this revolution possible, as Erika Fry and Sy ­Mukherjee report in “Big Data Meets Biology,” are the extraordinary new technologies that can now begin to make sense of the estimated 750 quadrillion bytes of health-related data we produce every day. That information, in turn, can help us find new cost efficiencies and improve care, many say.

It’s a fascinating story and one that offers hope that we can not only make progress against a litany of diseases, but also—just maybe—begin to reverse our soaring national health bill.

Which brings me to another important story in this issue, “Deep in Debt.” Veteran writer Shawn Tully, who has been expertly chronicling and analyzing the economy for Fortune readers for decades, digs into America’s deficit spending and shows plainly why it could lead to disaster. It’s a sobering read—and, I believe, a must-read.

And as with Erika and Sy’s story, the message is just waiting to be seen, hiding openly in the data.

A version of this article appears in the April 2018 issue of Fortune with the headline “Driven by Data.”