Washington  - The United States health-care system is the costliest in the world, yet leaves 46 million people uninsured, but a political consensus for dramatic changes remains elusive.

The paradox is tying the hands of President Barack Obama as his administration fights an uphill battle to pass the most significant overhaul of the health system in five decades.

If you ask the White House, the US health system is in dire crisis. Obama points to spending on medical care that is far higher than anywhere else in the developed world, weighing on both household budgets and the competitiveness of businesses.

"Whether you have health insurance or you don't have health insurance, we all know we can't continue down this path," Obama said at a town-hall meeting over the weekend in Colorado.

The US spent about 16 per cent of its economic output on health care, compared to just 11 per cent in France with the next highest rate, and a 2007 average across the developed world of 8.9 per cent, according to the Organization for Economic Cooperation and Development (OECD).

About half of all personal bankruptcies in the United States are at least partly due to medical expenses, according to a Harvard University study. Carmaker General Motors was partly driven into bankruptcy by high legacy costs for the pension and health-care benefits of generations of retired workers.

The quality of outcomes does not necessarily match the higher cost. Life expectancy in the US was 78.1 years in 2006, compared to an average of 79 across the OECD's 30 developed country members.

Yet, ask Americans whether they support changes and you will get mixed answers. While polls consistently show the majority want significant reforms, more than 80 per cent typically say they are happy with the health insurance and care they currently have.

"I have no complaints," said 62-year-old Diane Foster as she waited to pick up prescription drugs at a medical centre in the Virginia. "I guess the reforms could result in my premiums going up."

This disconnect - between reform in the abstract and real-life changes to their own status quo - makes it difficult to forge fundamental reforms that that do more than tinker around the edges.

Obama repeatedly insists that nobody who is happy with their coverage would be forced to switch plans.

The Obama administration has suggested that creating a government- run insurance option, a central plank that was billed as a necessary competitor with private insurers to lower costs, might be axed to win over some conservative opponents.

The US has long been wary of greater state involvement. Europe's more government-oriented systems have come under special fire from opponents who believe public interference in the private market will sharply reduce the quality of care. "Socialized medicine" has become a rallying cry for opponents of various proposals from Obama and his Democratic majority in Congress.

The US government already provides insurance for seniors, the poor, the military and its veterans. The high total costs mean the US government spends about as much to cover these groups as most other developed countries spend to cover their entire populations.

One of the chief problems is that many insurers have developed regional monopolies around the country. Experts argue that having a government insurance option, which has been the focus of debate in the US for weeks, is not essential to break their grip.

"This has emerged as the sharpest point of contention but probably not the most important element of reform," said Thomas Mann of the Washington-based Brookings Institution, a non-partisan think tank.

A possible compromise might be the creation of cooperatives - non- profit insurers controlled by consumers that would receive some federal backing. This is being considered by the Senate Finance Committee, one of five congressional committees that are working on health-care legislation.

Not all of the reform proposals are so controversial.

One key element is creating a "health exchange." This nationwide database would let consumers choose between insurance options, instead of being restricted to the handful of plans typically offered in any single region.

There is general agreement that any reform should prevent insurance companies from rejecting consumers with pre-existing health conditions. Many elderly patients, or those with chronic diseases, either face higher premiums or struggle to find a plan at all, if they try to buy insurance on the individual market.

Insurers currently charge lower rates to the young and healthy.

But insurance companies say part-and-parcel of that change will have to be a government requirement to buy health insurance. Without it, the young could hold off buying coverage on the knowledge that - protected by law against exclusion for pre-existing conditions - they can still get cheap rates if they become ill later in life.

Health insurance is currently optional in the United States, a policy that sets it apart from most other developed countries and is the chief reason that an estimated 46 million Americans remain uninsured.

Freedom of choice has long been a hallmark of US society, and the government forcing people to take insurance has been resisted. Obama himself opposed the idea during the 2008 election campaign, but has since shown he is open to it.

The debate will resume in earnest in September, when Congress returns from its summer recess. (dpa)