The CDC (a part of the US Public Health Service, which works to keep you and me alive) uses the best current methodology. That’s their job – that’s what we pay them for. If you’ve never learned any statistics, go to the library and ask the librarian to find you a book so you can understand the difference between causation and correlation, and why legitimate medical research very seldom uses the term “cause” – because the bar is so high.
Given your spirited defense of smoking, I find it hard to believe that you’ve never smoked. I did back in the day, and I know that the issue of choice is very difficult. Nicotine is more addictive than heroin, and kicking smoking is one of the hardest things I’ve ever done in my life. I finally succeeded because I developed bronchial pneumonia, and literally couldn’t breathe in smoke without having an asthma attack. If you’re hooked, get help. If you’re not hooked, quit talking about something of which you are ignorant.