A new study has ranked the NHS as the second most cost-effective health care system, after Ireland, in a table of 19 developed western nations, and finds the US system to be the least efficient and effective.

The study, reported in the Journal of the Royal Society of Medicine (JRSM), sought to "test the hypothesis that the USA healthcare system was superior to the NHS and 17 other western countries in reducing feasible mortality rates over the period 1979-2005," say the researchers, led by Professor Colin Pritchard of Bournemouth University.

They found that Gross Domestic Product health expenditure (GDPHE) in the US was the highest of the 19 nations during the period, in both current and average terms. However, 15 of the countries reduced their mortality rates significantly more than the US, while in the UK mortality rates in the "adult" (15-74 years) and "older" (55-74 years) age groups fell significantly more than in 12 other countries.

Overall, GDPHE averaged 7.4% among all 19 nations during the period, with higher than average spending in the US (12.2%), Germany (9.7%) and Switzerland (9.3%). Of those spending under the average, Spain's level was the lowest, at 6.8%, while Japan's was 7% and Finland, Ireland and the UK all spent 7.1%.

The researchers assessed the cost-effectiveness of each nation's health system by dividing its level of reduced mortality rate by its average GDPHE, and found that the most cost-effective system was Ireland's, followed by the UK and New Zealand. In contrast, the third-least cost-effective was Switzerland, followed by Portugal and, in last place, the US.

"Ireland, the UK and New Zealand had almost three times the cost-effectiveness ratio of the three lowest countries, in effect doing more with proportionately less over the period," say the researchers.

"On these measures, the US healthcare system is the least effective and efficient of western countries," they add, and ask: "how can the poor USA results be explained bearing in mind the notion that market forces are assumed to lead to greater effectiveness and productive efficiency?"

Turning to the "better than expected" UK clinical outcomes, they note that these appear to be at odds with the recent high-profile debate about cancer survival rates in Britain. But, they say, in terms of actual cancer mortality rates rather than the "more ambiguous survival rates," their research found better results for the UK than the USA, which appear to be linked by major additional funds going to cancer care.

The authors say they hope their findings "might be a boost to patients and their families in every western country but especially those using the NHS, and that some recognition goes to UK frontline staff, who over the past 25 years have achieved more with relatively less."