Doll and Hill first evaluated the proposition that smoking was a risk factor for lung cancer in a case–control study (Doll and Hill, 1950). They found that, of 649 men with lung cancer (cases), 647...

Doll and Hill first evaluated the proposition that smoking was a risk factor for lung cancer in a case–control study (Doll and Hill, 1950). They found that, of 649 men with lung cancer (cases), 647 had smoked at some time, compared with 622 of the 649 men without lung cancer (controls)

(a) Draw up a clearly labelled and appropriate 2 2 table to show these data. (b) How many times as likely was a smoker to develop lung cancer than a non-smoker? (c) Calculate the proportion of lung cancers attributable to smoking among (i) smokers and (ii) the whole population. (d) What are these measures called and how does their interpretation differ?