smoking odds

Australia has some pretty gruesome warning labels on packs of cigarettes (although not nearly as graphic as what you'd find on a pack in Brazil). I've always wanted to know just how bad smoking is for you, by the numbers. Does it raise your chance of dying from 1-2% or 1 to 50%?

Well, I have a favorite new webpage, the book of odds, where you can look up the chances of pretty much anything. So for example, in the US in recent years

Percent of people who smoke: 20%

Percent of married women who smoke: 15.2%

Percent of women with advanced degrees who smoke: 6.6%

I'm just sayin'!

So then this article talks about the deadliest cancers and your chances of dying from what. With a little help from some Bayesian Statistics:

P(S) = probability of anyone being a smoker = 20% (nevermind married women with advanced degrees)

P(C) = probability of anyone dying from lung cancer = 6%

P(S|C) = probability that, if you died from lung cancer, you were a smoker = 90%

therefore

P(C|S) = P(S|C)*P(C)/P(S) = 0.90 * 0.06 / 0.20 = 0.27

This means, if you smoke, your chance of dying from lung cancer : 27%

Conversely, if you don't smoke, your chance of dying from lung cancer: = 0.1 * 0.06 / 0.80 = 0.75%

To sum up, you are 36 times more likely to die from lung cancer if you smoke than if you don't smoke.

Savor the flavor while you can I guess!