I can't tell where that data came from, so it is meaningless.
Here is a source that explains it numbers.
http://www.economist.com/media/pdf/QUALITY_OF_LIFE.pdfThey rank the US as #13. However, if you go to the bottom, you see that the US blows away the other countries except Luxemburg in GDP per capita. Norway is a close third. Canada would probably do well if you restricted it to the population that lived within commuting distance to the US.
The weight assigned to income in that study is 11.5. The life expectancy is given a weight of 15. The US gets a low score there because about 30% of our population is obese, as compared to 10% in most other countries. The divorce rate is given a weight of 14.3, which is a bizarre weight considering how many people do not even get married. And so.
Basically studies like that are nonsense made up by Europeans to get around the plan and simple fact that if you like having stuff, you are better off being in the US.