That seems like a bit of an overstatement[0] considering all the categories that the US isn't #1, e.g. Life expectancy (#49) [1]. Granted, these rankings are quite old, but you can pretty easily find others, for example Hans Rosling's presentations on health care.
EDIT: This is not a dig at the US as such. I just think it's time for a reality check for many people.
[0] Or, rather, the US doesn't seem to be very effectual at improving the situation.
[1] http://en.wikipedia.org/wiki/International_rankings_of_the_U...