Question 1
Failing to account for age cohort effects in smoking prevalence may:
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 3
An example of passive follow-up in cohort studies is:
Question 4
Subjects for an exposure-based cohort study of lead exposure would be selected most appropriately from: