The controversy over Obamacare and now the raucous debate over its possible repeal and replacement have taken center stage recently in American politics. But health insurance isn’t the only health-care problem facing us—and maybe not even the most important one. No matter how the debate in Washington plays out in the weeks ahead, we will still be stuck with astronomical and ever-rising health-care costs. The U.S. now spends well over $10,000 per capita on health care each year. A recent analysis in the journal Health Affairs by the economist Sean P. Keehan and his colleagues at the federal Centers for Medicare and Medicaid Services projects that health spending in the U.S. will grow at a rate of 5.8% a year through 2025, far outpacing GDP growth.

Our health-care system is uniquely inefficient and wasteful. The more than $3 trillion that we spend each year yields relatively poor health outcomes, compared with other developed countries that spend far less. Providing better health insurance and access can help with these problems, but real progress in containing costs and improving care will require transforming the practice of medicine itself—how we diagnose and treat patients and how patients interact with medical professionals. In medical training, private sector R&D, doctor-patient relations and public policy, we need to move much more aggressively into the era of smart medicine, using high-tech tools to tailor more precise and economical care for individual patients. This transition won’t be easy or fast—the culture of medical practice is famously conservative, and new technology always raises new concerns—but it has to be part of the solution to our health-care woes.

Radical new possibilities in medical care are not some far-off fantasy. Last week in my clinic I saw a 59-year-old man with hypertension, high cholesterol and intermittent atrial fibrillation (a heart rhythm disturbance). Before our visit, he had sent me a screenshot graph of over 100 blood pressure readings that he had taken in recent weeks with his smartphone-connected wristband. He had noticed some spikes in his evening blood pressure, and we had already changed the dose and timing of his medication; the spikes were now nicely controlled. Having lost 15 pounds in the past four months, he had also been pleased to see that he was having far fewer atrial fibrillation episodes—which he knew from the credit-card-size electrocardiogram sensor attached to his smartphone.

In my three decades as a doctor, I have never seen such an acceleration of new technology, both hardware and software, across every dimension of medical practice. I have also had the opportunity to advise and collaborate with several companies on these developments. The new tools are not just more powerful, precise and convenient; they are more economical, driven by the information revolution’s ability to deliver, as Moore’s Law holds, ever-increasing computing power for less money.

Consider the biggest line items in the 2016 national health-care budget, according to Mr. Keehan and his colleagues: more than $1 trillion for hospital care, $670 billion for doctor and clinician services, $360 billion for drugs. And compare the often sorry outcomes: more than 1 in 4 patients harmed while in the hospital; more than 12 million serious diagnosis errors each year; a positive response rate of just 25% for patients on the top 10 prescription medications in gross sales.