Chapter 8. Cohort Studies
Which of the following is NOT a feature of a cohort study?
A. Exposure is determined by randomization.
B. Exposure level must be assessed.
C. Subjects are followed for the development of disease.
D. Risk ratio is a commonly used measure of effect.
E. It can be used to study either protective or harmful exposures.
A rate ratio (95% CI) calculated from a cohort study is 1.7 (0.8, 3.4). The most appropriate interpretation is
A. the exposure is associated with a lower rate and the result is statistically significant.
B. the exposure is associated with a lower rate, but the result is not statistically significant.
C. the exposure is associated with increased rate, and the result is statistically significant.
D. the exposure is associated with increased rate, but the result is not statistically significant.
Each of the following is a feature of a retrospective cohort study EXCEPT
A. it is efficient for the study of rare exposures.
B. information on exposures typically is accurate and complete.
C. it is efficient for the study of slowly developing diseases.
D. it typically can be completed more quickly than a prospective cohort study.
E. it may rely on already collected information.
Misclassification of disease status, if it is unrelated to exposure, is expected to have what impact on the results of a cohort study?
A. Result in a reversal of the association of interest
B. Increase the apparent strength of association
C. Decrease the apparent strength of association
D. Impact cannot be predicted
The null value of the rate ratio is
If initial exposure status changes during ...