Q1)Consider the following two studies reported in the New York Times:

a. A British study reported (December 3, 1998) that, of smokers who get lung

cancer, "women were 1.7 times more vulnerable than men to get small-cell

lung cancer." Is 1.7 an odds ratio, or a relative risk?

b. A National Cancer Institute study about tamoxifen and breast cancer

reported (April 7, 1998) that the women taking the drug were 45% less

likely to experience invasive breast cancer compared with the women taking

placebo. Find the relative risk for (i) those taking the drug compared to those

taking placebo, (ii) those taking placebo compared to those taking the drug.

Q2)In the United States, the estimated annual probability that a woman over the age

of 35 dies of lung cancer equals 0.001304 for current smokers and 0.000121 for

nonsmokers[M. Pagano and K.Gauvreau, Principles of Biostatistics, Belmont,

CA: Duxbury Press (1993), p. 134].

a. Calculate and interpret the difference of proportions and the relative risk.

Which is more informative for these data? Why?

b. Calculate and interpret the odds ratio. Explain why the relative risk and

odds ratio take similar values.