You've naively bought into what's called "Nihonjinron." And you're being naive about your health care system.<quoted text>
Japan is a lot more homogenous than the USA. You have people from all over the world, and their diseases and bad habits, converging on the USA. Probably the biggest mix in one Petri dish in the world. China, Japan, and most others don't have that issue of so many foreign introduced diseases.
The UK and Canada have lots of immigrants - Canada's population only grows through immigration. They do not have the TB problems USA does. Neither countries have people going bankrupt because of health care.
Japan has lots of foreigners. They're just not visible because they're Asians. Well, the Brazilians are visible. Anyways, Japan also has among the highest population density per kilometer in the world, meaning that our potential for disease is much, much greater than yours - but we don't have it.
China is not a first world nation, except sort of in its main cities. It therefore doesn't count among the nations I'm speaking to: the G8 nations. China has massive problems and massive health problems (due mostly to pollution). Sure, you can compare your health care to theirs if you like.
On the world stage, US ranks around 30 - near Afghanistan in most health indicators.
You don't have an excuse. The worlds most powerful economy, cheap on its citizens. Afghanistan has an excuse, China has lots, American, none.