1) A major advantage of cohort studies over case-control studies with respect to the role of a suspected factor in the etiology of a disease is that:
A. they take less time and are less costly.
B. they can utilize a more representative population.
C. it is easier to obtain controls that are not exposed to the suspected factor.
D. they permit direct estimation of risk of disease in those exposed to the suspected factor.
E. they can be done on a double-blind basis.
2) Subjects for an exposure-based cohort study would be selected most appropriately from:
A. certain occupational groups such as battery workers
B. the residents of a large U.S. county
C. male Harvard alumni from 1916 to 1950
D. all of the above
3) Failing to account for age cohort effects in smoking prevalence may:
A. obscure the fact that older cohorts had higher prevalence of smoking in comparison to younger cohorts.
B. obscure the fact that there had been a shift in the age of onset for lung cancer toward earlier ages.
C. obscure the differences in smoking prevalence for males and females, and by level of education.
D. B and C
4) Cohort study is to risk ratio as:
A. ecologic fallacy is to cross-sectional study
B. genetics is to environment
C. case-control study is to odds ratio
D. A and C