Suppose researchers want to address the question of whether new car safety features such as
multiple airbags have made a difference in motor vehicle fatality rates.
Which of the following
study designs would best address that question?
90,000 healthy women enrolled in a study to examine environmental effects and
All women had given blood samples at the start of the study.
women were followed for 10 years, 1200 cases of breast cancer had developed.
selected a random sample of 1200 women without breast cancer from the base population of
The blood samples of the 1200 women with breast cancer and the 1200
women without breast cancer were analyzed to determine the presence of DDT (a persistent
What type of study design is described?