[aamar]

You are right, the 2009 Wilpers paper does bucket out current and former smokers, as well as look at BMI and other factors. The authors should be credited for that. But when those factors are considered, the null hypothesis is only barely rejected at 95% confidence. The Kronick paper uses a much larger dataset and discusses the issue of what is controlled for more extensively.

[Fomite]

So wait, now not only are we using hypothesis testing as your sole means of evaluating whether or not an effect exists, but you're moving the threshold around because...you want to?

[aamar]

No, I don't think I'm arguing that. It's not a question of any one methodology always being better than others, or correlation studies always being wrong. The question is what we should reasonably believe in light of several analyses of various strengths.