Part B: Case Control Study Design (18 points)

Suppose that a case-control study was conducted in the United States to find out whether a Black woman's exposure to racism during pregnancy influenced her risk of giving birth prematurely. Investigators selected 500 cases who were hospitalized for premature delivery and 1,000 controls. The study found that 90 case mothers and 50 controls mothers reported overt incidents of racism during their pregnancy. Use the information to answer the following questions.

1. Set up the two-by-two table for these data. (4 points i.e., 1 point per cell)

	Cases	Controls
Experienced Racism
Did Not Experience Racism

1. Calculate the appropriate measure of association and interpret your result. (2 points for computation, 3 points for interpretation)

2.Using Barnet Woolf formula, compute 95% Confidence Interval for the Odds ratio you computed in (ii). Interpret your result. (2 points for computation, 3 points for interpretation)

3. Suppose that the investigators hire you as a consultant epidemiologist to help them design this study. Briefly describe the control group that you would advise them to select and justify your choice. (4 points)

4. The investigators also ask you to describe the purpose of the control group in a case-control study. What would you tell them? (4 points)