1. A retrospective cohort study is conducted of the relationship between the use of estrogen and coronary heart diseases. The records of 5000 women are reviewed and followed for 15 years for the development of myocardial infection. They were classified as 2000 estrogen users and 3000 non-estrogen users. Of those estrogen users 60 had an episode of a myocardial infarction. Of those who did not use estrogen, 65 had a myocardial infarction. fill in 2 x 2 table.

Myocardial Infarctions

	Yes	No	Totals
Estrogen users
Estrogen nonusers
Totals			5000

1. (3 points) Compute the appropriate measure of association for this study and interpret the results.
2. (3 points) Compute the attributable-risk percent. Interpret the results