Australia's healthcare system has been ranked among the best in the developed world by a team of American researchers who have ranked their own country's system the worst.

Key points: Overall the highest performers were UK, Australia, Netherlands, New Zealand, Norway

Overall the highest performers were UK, Australia, Netherlands, New Zealand, Norway US ranked last overall had the highest rate of mortality

US ranked last overall had the highest rate of mortality But Australia ranked eighth for equity

In their study of 11 different national health care models, researchers at the New York-based Commonwealth Fund ranked Australia's mixed public-private system second best.

They concluded the United Kingdom's National Health Service was the best system overall, followed by Australia, then the Netherlands, with Norway and New Zealand sharing fourth place.

Comparing Australia and the other countries to their homeland, the authors said: "The US performs relatively poorly on population health outcomes, such as infant mortality and life expectancy at age 60."

"The US has the highest rate of mortality amenable to health care and has experienced the smallest reduction in that measure during the past decade.

"Despite spending nearly twice as much as several other countries, the country's performance is lacklustre."

The publication of the study's conclusions have come as US President Donald Trump puts pressure on Republican senators to repeal his predecessor Barack Obama's healthcare reforms.

In May, House Republicans narrowly voted through the Obamacare repeal bill, and their counterparts in the Senate are due to vote on the repeal in the next few weeks.

Australia has better healthcare than we do: Trump

Healthcare system performance scores.

Speaking over the weekend, Mr Trump said his reforms would make America's healthcare system work better, even though two senators from the President's own party have declared they cannot vote for it.

Mr Trump has since been pushing them to change their minds.

"The Senate is going to vote on legislation to save Americans from the Obamacare disaster," Mr Trump said.

"Obamacare has wreaked havoc on American lives, and if we don't replace it the calamity will only get worse, and I mean get worse by a lot."

In May, Mr Trump used a press conference alongside Prime Minister Malcolm Turnbull in New York to suggest Australia's system was better than his country's.

"We have a failing healthcare," he said.

"And I shouldn't say this to our great gentleman and my friend from Australia, because you have better healthcare than we do."

The comments were met with confusion in the US, where Democrats pointed out Australia's system included a publicly funded Medicare system that was more comprehensive than America's.

Australian healthcare below average on equity: report

Despite Mr Trump's comments about Australia's system, analysts say the Obamacare repeal bill he is championing would actually make the American system less like Australia's, not more.

The study noted out-of-pocket costs for Australians are continuing to increase. ( AAP )

Health policy analyst at the Menzies Centre at the University of Sydney, Dr Lesley Russell, said very few experts think Mr Trump's reforms will improve the health care system in the US.

"It's very clear that Obamacare has made a substantial difference to the number of people who have health insurance and to the quality of care," she said.

"What the Senate Republican proposals will do is take health insurance away from 23 million people who currently have it, and will leave the 28 million Americans who were not reached by Obamacare without coverage.

"Most people who work in health policy are saying that the Republican proposals as espoused by [House Speaker] Paul Ryan, [Senate Majority Leader] Mitch McConnell and Donald Trump will be a disaster."

Asked to comment on the Commonwealth Fund finding that Australia's system was among the world's best, Dr Russell said the conclusion should be understood in context.

"We know that out-of-pocket costs for Australians are continuing to increase, in large part because of the Medicare freeze that the Government has imposed over the last few years," she said.

"So any self-congratulations and praise should be tempered, because Australia ranks very poorly on the equity measure."

According to the Commonwealth Fund study's authors, Australia was below average on equity.

Although Australia was ahead of the United States, France and Canada on equity, it was ranked behind the UK, the Netherland, New Zealand and Germany.

But overall the American authors still thought many of those countries could learn from Australia's system.

"The top performing countries — the UK, Australia and the Netherlands — could offer important lessons to the US and other countries," they said.