The $2.7 trillion U.S. health-care system lags behind other nations in improving its citizens' health even as spending has doubled, increasing faster than any other industry over the past decade, researchers said.

The rise in costs have been driven primarily by the price of services, drugs and devices rather than higher demand from an aging population, according to a report today on U.S. spending trends in the Journal of the American Medical Association. The analysis also found that two-thirds of spending is for people younger than 65 with chronic illness, though most of the focus on cutting costs has been centered on the elderly.

Health-care expenditures have doubled since 1980, accounting for 18 percent of U.S. gross domestic product and leading to financial success for drugmakers, device companies, hospitals, insurers and other providers, the authors said. Yet patients haven't seen the same gains.