Americans are the most likely to go without health care because of the cost and to have trouble paying medical bills even when insured, a survey of 11 wealthy countries found Thursday.
"The US stands out for the most negative insurance-related experiences," the New York-based Commonwealth Fund, the private foundation that carried out the study, said in an accompanying statement.
The study found that a third of US adults "went without recommended care, did not see a doctor when sick, or failed to fill prescriptions because of costs," it said.
That compares to as few as five to six percent in the Netherlands and Britain, according to the study.
A fifth of Americans had "major problems" paying medical bills, compared to nine percent in France, the next highest country, two percent in Britain, three percent in Germany and four percent in the Netherlands, it said.
Americans were also the most likely to have disputes with their insurance providers or discover insurance would not pay as they had expected.
The survey, published on the Health Affairs website, was conducted among 19,700 adults from Australia, Canada, France, Germany, the Netherlands, New Zealand, Norway, Sweden, Switzerland, Britain and the United States.
The survey's findings reflect the widespread frustration with health care in the United States that fueled the cantankerous debate over a major overhaul signed into law by President Barack Obama in March.
"We spend far more on health care than any of these countries, but this study highlights pervasive gaps in US health insurance that put families' health and budgets at risk," said Cathy Schoen, the lead author of the study.
"In fact, the US is the only country in the study where having health insurance doesn't guarantee you access to health care or financial protection when you're sick. This is avoidable."
The US health insurance system also stood out for its complexity.
The study found that 31 percent of Americans either spent "a lot of time" dealing with insurance paperwork, had their insurer deny a claim, or had their insurer pay less than they anticipated.
In contrast, only 13 percent of Swiss adults, 20 percent of Dutch and 23 percent of Germans reported similar problems. All three countries have competitive health insurance markets.
The study found that just 58 percent of Americans were confident they would be able to afford the care they needed, the lowest rate in the survey.
Seventy percent were confident they would receive the most effective care, compared with 84 to 92 percent of adults in France, Germany, the Netherlands, New Zealand, Switzerland and Britain.
"The good news is that there are opportunities to learn from other countries," said Commonwealth Fund President Karen Davis, who went on to praise the health reform bill.
"The Affordable Care Act reforms will provide affordable insurance options for the uninsured, make sure insurance pays for essential care and provide financial security for millions."
The 940-billion-dollar bill will extend coverage to some 32 million Americans who currently have none, ensuring 95 percent of under-65 US citizens and legal residents will have health insurance.
Obama's Republican rivals have however vowed to do everything they can to roll back the measure -- which they view as a costly expansion of "Big Government" -- with their newly-won majority in the House of Representatives.