Isn't smoking much more common among the Chinese than this sample suggests? I would expect a random sample to include more smokers than not. It may imply that t

Isn't smoking much more common among the Chinese than this sample suggests? I would expect a random sample to include more smokers than not. It may imply that the act of smoking or the associated health states reduce the likelihood of infection, even if they increase the likelihood of a bad infection if it does land.