2. As an epidemiologist you are going to investigate the effect of a drug suspected of causing

malformations in newborn infants when the drug in question is taken by pregnant women during the

course of their pregnancy. As your sample you will use the next 200 single births occurring in a given

hospital. For each birth a medication history will be taken from the new mother and from her doctor.

[N.B.: These mothers are considered to have been followed prospectively during the entire course of

their pregnancy, because a complete and accurate record of drug use was maintained during pregnancy.]

The resultant data are:

Forty (40) mothers have taken the suspected drug during their pregnancy.

Of these mothers, 35 have delivered malformed infants. In addition, there are 10 other infants born with

malfunctions or malformations.

a) What is the number of mothers who did not take the drug and did not deliver a malformed infant?

b) What is the exposure variable of this study?

c) What is the outcome variable of this study?

d) What is the incidence in the exposed?