Data published in an OECD report called "Healthcare at a glance 2007" show that its 30 member economies spent an average of 9.0 percent of their gross domestic product (GDP) on health needs in 2005 compared with 8.6 percent in 2003, and between 7.8 to 8.5 percent from 1997 to 2002.
In eight countries, health care spend in 2005 accounted for more than 10 percent of GDP, compared with only four in 2000 and three in 1995.
The leading spenders were the United States -- which allotted 15.3 percent to health needs -- followed by Switzerland with 11.6 percent, France with 11.1 percent, Germany with 10.7 percent and Belgium with 10.3 percent.
At the bottom end of the expenditure table were Mexico with 6.4 percent, Poland with 6.2 percent and South Korea with 6.0 percent.
Average US expenditure in 2005 was 6,401 dollars per inhabitant -- which is more than 2.25 times the OECD average of 2,759 dollars.
The OECD attributed increased health care expenditure to aging populations as well as medical progress and improved living conditions.
The report found that in OECD member countries, the average percentage of the population over 65 has risen to almost 15 percent, with Japan, Italy and Germany at almost 20 percent.
The study pointed to pointed to an "old-age dependency ratio" which looks at the elderly population as a proportion of the workforce, as a useful means of determining future health care needs.
It said the current OECD average of just over 20 percent was likely to more than double by 2050, "resulting in a ratio of one elderly person to every two of working age".
"Since older populations tend to be in poorer health and thus in greater need of health and long-term care, population aging can be expected to lead to increased public expenditure in those areas," the OECD said.
Elsewhere the study said life expectancy at birth came to an average 78.6 years in OECD countries in 2005, up 10 years from that in 1960.
Infant mortality has fallen sharply in the OECD, down to 5.4 deaths per 1,000 births in 2005 from 30 in 1970.