Re part of your Title
China and Hong Kong not the same thing old chap. See:-
https://www.cia.gov/library/publicat.../2102rank.html
We know this list must be right, according to Edward, they've done the research. Interesting Snippets from the life expectancy league table:-
No. 100 China
No. 51 US of A
No. 30 UK
No. 9 Hong Kong
No. 2 Macau
Other factors exist I hear you say - correct! But still, not quite the killer it's claimed.