Country ranking

1: Oman 2: Malta 3: Italy 4: France 5: San Marino 6: Spain 24: UK 72: US 189: Namibia 190: Zambia 191: Zimbabwe

Source: WHO

Several European countries did well, among them Italy, France and Spain, and much smaller states such as Malta, Andorra and San Marino also made the top 10.

The US - home to some of the finest hospitals in the world - managed only a paltry 72nd place.

Oman was nudged to the top by a spectacular performance in reducing child mortality - from 310 per 1,000 births to just 18 per 1,000 over the past four decades.

HIV handicap

The authors of the report conceded that countries with a high prevalence of HIV and Aids gained an artificially low ranking on the table as a result, simply because the effects on average life expectancy were so pronounced.

An accompanying editorial by Professor Martin McKee, from the London School of Hygiene and Tropical Medicine, pointed out flaws in the methods used by the researchers - but said it was right to try to rank the countries, even if the results were not particularly reliable.

Health systems are not simply measured in terms of prolonging life

Tony Harrison, King's Fund

He wrote: "It has invoked the concept of stewardship, which implies a more active involvement in promoting health than most governments have previously assumed.

"It has not, however, provided a valid answer to the question of whether one system is better than another."

Tony Harrison, from the Kings Fund, an independent think tank which specialises in the analysis of health systems, agreed that while the study was an interesting exercise, it could not be relied upon.

He told BBC News Online: "Health systems are not simply measured in terms of prolonging life. There are many treatments - such as cataract removal, for example, which greatly improve quality of life, without necessarily extending it.

"There are, in addition, many other factors which determine good health and longevity, not just the state of the health system."

He added: "I think there is also a degree of diminishing returns for the most modern health systems. Countries like Oman are achieving improvements in mortality which the UK was achieving decades ago.

"Investment of large amounts of money will only produce small improvements in longevity in the UK."