Ireland is ranked 32nd of 191 countries in a new table of health systems based on efficiency produced by the World Health Organisation.
The table involves a complex calculation, estimating efficiency in turning expenditure into "healthy life expectancy".
The researchers took account of the level of education and adjusted for the number of years of healthy life people can expect in rich and poor countries.
They found that "efficiency in producing health" varied greatly between countries, from nearly fully efficient to almost completely inefficient. The table was drawn up by a team led by Mr David Evans, from the WHO's Global Programme on Evidence for Health Policy, in Geneva, based on analysis of figures between 1993 and 1997.
The findings, reported in the British Medical Journal published today, imply that although some countries may be close to achieving their health potential, others were nowhere near this goal. Countries with the best levels of health did not necessarily have the most efficient health systems.
Oman topped the new table, followed by Malta, Italy, France, San Marino, Spain, Andorra, Jamaica, Japan and Saudi Arabia. The UK was 24th, eight places above Ireland. Countries ranked immediately beneath Ireland were Turkey, Belize, Canada, Cuba and El Salvador. The bottom 10 countries were all in Africa. South Africa was 182nd followed by Sierra Leone, Swaziland, Democratic Republic of the Congo, Lesotho, Malawi, Botswana, Namibia, Zambia and, lastly, Zimbabwe.
Performance increased sharply with health expenditure per capita. Countries with a history of civil conflict or high prevalence of HIV and AIDS were the least efficient. One reason Oman performed so well was thought to be because it had drastically reduced child mortality over the past 40 years. Many other high ranking countries were characterised by healthy Mediterranean diets.
The researchers wrote: "Performance increased greatly with expenditure up to about $80 dollars per capita a year, suggesting it is difficult for systems to be efficient at low expenditure.
"There seems to be a minimum level of health expenditure below which the system simply cannot work well. We estimate it would cost just over six billion dollars a year (less than 0.3 per cent of global annual health expenditure) to increase health spending to this threshold in the 41 countries with lowest expenditure."
They added that despite the need to increase expenditure in poor nations, most countries could benefit by cutting waste and improving allocation of resources.