A summary of some of the sources of bias in WHO's health care quality index:

Michael Moore made great sport in his film "Sicko" of pointing out that the World Health Organization (WHO) ranked US health care a lowly 37th in the world, considerably below France and Canada. But, much like Mr. Moore himself, the rankings are far from impartial or empirically sound. [. . .] But an examination of the index tells us more about the ideology of the authors than it does about the quality of American healthcare. [. . .] The most obvious bias is that 62.5% of their weighting concerns not quality of service but equality. In other words, the rankings are less concerned with the ability of a health system to make sick people better than they are with the political consideration of achieving equal access and implementing state-controlled funding systems.

One of the five factors in the calculations is called "Financial Fairness". This favours systems that charge richer people more health tax, irrespective of how much, or little, health service they use. Colombia comes top. This measure has nothing to do with the quality of healthcare, yet it counts for a quarter of the weighting.
[. . .]
The rankings include measures for "health level" and "responsiveness." "Health Level" is their way of saying life expectancy, while "responsiveness" refers to a survey based on "respect for persons" and elements such as speed of service, convenience and choice—yet even in these cases half the weighting is determined by considerations of equality. Thus a country with a poor level of "responsiveness" throughout the population will score higher than a country with a good level in some parts and an excellent level in others.
[. . .]
Americans generally believe that whatever the other problems with the US healthcare system, its standards of care are high. In the details of the rankings there is evidence to support this belief. It shows the USA as having the most responsive health system in the world but this measure makes up only a small part of the overall rankings.