And two big pieces of the cost savings are:

1 - using buying leverage to negotiate prices, something republicans owned by the drug and device industry specifically banned (see eg [1])

2 - rationality about end of life care, which we spend a lot of money on -- 20%+ off the top of my head. As many doctors have shared, they often choose not to aggressively treat terminal illnesses and focus on quality of life. Unfortunately (remember Sarah Palin's death panels, and let's all thank John McCain for bringing that snowbilly grifter to the national stage), attempts to do things like pay doctors to sit down with patients and have end of life conversations, explaining what is happening have been successfully yet stupidly fought off. Whereas when doctors talk about how they die, they often chose to undergo very little treatment [2,3]

Almost all medical professionals have seen what we call “futile care” being
performed on people. That’s when doctors bring the cutting edge of
technology to bear on a grievously ill person near the end of life. The
patient will get cut open, perforated with tubes, hooked up to machines, and
assaulted with drugs. All of this occurs in the Intensive Care Unit at a
cost of tens of thousands of dollars a day. What it buys is misery we would
not inflict on a terrorist. I cannot count the number of times fellow
physicians have told me, in words that vary only slightly, “Promise me if
you find me like this that you’ll kill me.” They mean it. Some medical
personnel wear medallions stamped “NO CODE” to tell physicians not to
perform CPR on them. I have even seen it as a tattoo. [2]

This doctor summarizes his choices as

my physician has my choices. They were easy to make, as they are for most
physicians. There will be no heroics, and I will go gentle into that good
night. [2]

A different article

Research shows that most Americans do not die well, which is to say they do
not die the way they say they want to — at home, surrounded by the people
who love them. According to data from Medicare, only a third of patients die
this way. More than 50 percent spend their final days in hospitals, often in
intensive care units, tethered to machines and feeding tubes, or in nursing
homes. [3]

There is almost always something that a doctor can do, but patient comfort is approximately priority F.

More typical was an almost eighty-year-old woman at the end of her life,
with irreversible congestive heart failure, who was in the I.C.U. for the
second time in three weeks, drugged to oblivion and tubed in most natural
orifices and a few artificial ones. Or the seventy-year-old with a cancer
that had metastasized to her lungs and bone, and a fungal pneumonia that
arises only in the final phase of the illness. She had chosen to forgo
treatment, but her oncologist pushed her to change her mind, and she was put
on a ventilator and antibiotics. Another woman, in her eighties, with
end-stage respiratory and kidney failure, had been in the unit for two
weeks. Her husband had died after a long illness, with a feeding tube and a
tracheotomy, and she had mentioned that she didn’t want to die that way. But
her children couldn’t let her go, and asked to proceed with the placement of
various devices: a permanent tracheotomy, a feeding tube, and a dialysis
catheter. So now she just lay there tethered to her pumps, drifting in and
out of consciousness. [4]

And finally -- you should read all of [5], though it's heart-wrenching -- many terminal patients don't want to be aggressively treated when outcomes and the experience are fully explained. A close family member had to make similar choices and chose to die at home. The surgeons and oncologist where happy to keep going, but he was dying, and nothing the doctors could do would change that. They could only prolong for another couple months the inevitable, at the price of excruciating pain, repeated surgeries, and drugs that made him feel terrible. He chose to die at home. And not only is this far more humane, but far cheaper.

[1] http://www.politifact.com/wisconsin/statements/2012/sep/04/t...

[2] http://www.zocalopublicsquare.org/2011/11/30/how-doctors-die...

[3] http://www.nytimes.com/2013/11/20/your-money/how-doctors-die...

[4] http://www.newyorker.com/magazine/2010/08/02/letting-go-2

[5] http://www.newyorker.com/magazine/2010/08/02/letting-go-2