CIGARETTE SMOKING DATA:

Cigarette Smoking Data for the Cohort and the U.S. as of 1965
  Cohort U.S.
Percentage never smoked cigarettes
Percentage current, 1 pack or less
Percentage current, more than 1 pack
Percentage former		 24
34
27
15		 24
40
15
21

The above Table shows the results for smoking data for the cohort and for the V.S. population, as of 1965 (1965 was chosen because smoking habits in the 1960s would be the most relevant for causing larynx cancers observed in the late 1970s or early 1980s, when most larynx cancers occurred in our cohort). Data on drinking are not presented here but showed the cohort and the US. population in general to have similar drinking habits.

QUESTIONS

After considering the above, try and answer the following questions:

  1. QUESTION 8. Do the data in the above Table indicate that the exposed cohort smoked more than the U.S. population sample? Smoking causes an approximate tenfold increase in larynx cancer rates (smokers versus nonsmokers). What would you guess would be the rate ratio of larynx cancer rates (exposed versus nonexposed) due to smoking differences alone?