Choose the best answer from the 6 multiple choice questions

Question 1

Cohort study is to risk ratio as:

Question 1 options:

ecologic fallacy is to cross-sectional study

genetics is to environment

case-control study is to odds ratio

A and C

Question 2

A five-year prospective cohort study has just been completed. The study was designed to assess the association between supplemental vitamin A exposure and mortality and morbidity for measles. The RR for incidence of measles was 0.75 and the RR for measles mortality was 0.5.

Which statement is correct?

Question 2 options:

A cohort study is not an appropriate study design in this case because the association between one exposure and two different outcomes is being considered

One of the problems that this study may have faced is individuals lost to follow-up during the five-year period

A cohort study is not a good design to study this association because measles is a very common disease

None of the above

Question 3

Regarding the RR reported above, which statement is correct

Question 3 options:

Exposure to vitamin A appears to protect against morbidity and mortality for measles.

Exposure to vitamin A appears to be a risk factor for morbidity and mortality for measles

Exposure to vitamin A is not associated with morbidity and mortality for measles

Exposure to vitamin A is a risk factor for morbidity and a protective factor for mortality for measles

Question 4

Subjects for an exposure-based cohort study (when the exposure of interest is rare) would be selected Most appropriately from:

Question 4 options:

certain occupational groups such as battery workers

the residents of a large U.S. county

male Harvard alumni from 1916 to 1950

all of the above

Question 5

Nested case-control studies:

Question 5

use subjects drawn from a cohort study.

provide a degree of control over confounding

reduce the cost of collecting exposure information

all of the above

Question 6

Practical considerations in the design of cohort studies do not usually include

Question 6 options:

availability of exposure data

size and cost of the cohort

follow-up issues

age of the investigator