US health care costs more than in other countries because we pay more per unit of care. Ezra Klein spoke with Kaiser Permanente CEO George Halvorson:

There is a simple explanation for why American health care costs so much more than health care in any other country: because we pay so much more for each unit of care. As Halvorson explained, and academics and consultancies have repeatedly confirmed, if you leave everything else the same — the volume of procedures, the days we spend in the hospital, the number of surgeries we need — but plug in the prices Canadians pay, our health-care spending falls by about 50 percent.

Wasn’t  it the role of Insurance firms to control health care costs? The article contains set of charts from the International Federation of Health Plans Comparative Price Report to demonstrate the significant difference in fees for medical services and procedures.