Question 1:

• Suppose (hypothetically) you did a study to evaluate the effect of smoking on the risk of mortality
• You randomized 20-year-olds to smoke 1 pack of cigarettes per day or not to smoke
• You followed the study participants for 100 years with no lost to follow-up

What would you expect the incidence rate ratio for mortality for smoking versus not smoking (IRR) to be?

Group of answer choices

A. IRR < 1

B. IRR > 1

C. IRR (approximately) = 1

Question 2:

• Suppose (hypothetically) you did a study to evaluate the effect of smoking on the risk of mortality
• You randomized 20-year-olds to smoke 1 pack of cigarettes per day or not to smoke
• You followed the study participants for 100 years with no lost to follow-up

What would you expect the cumulative incidence rate ratio (RR) for mortality for smoking versus not smoking to be?

Group of answer choices

A. RR < 1

B. RR > 1

C. RR (approximately) = 1