Answer to Question 1
The relative risk is a comparison of the risk of some health-related event, such as disease or death, in two groups. If the relative risk is greater than 1.0, the exposed group is at greater risk of the health-related event than the unexposed group.
Answer to Question 2
A retrospective cohort study examines previous data in an effort to look back in time to reconstruct exposures and health outcomes, whereas prospective cohort studies follow a group into the future.