Question: An investigator had data relating the effect of OC use on heart disease for 15,000 women aged 40 to 44 years. The investigators learned that among 5000 current OC users at the start of the study, 13 experienced a myocardial infarction (MI) during the next three years; among 10,000 nonusers of OCs, 7 experienced a MI during the next three years. See discussion on page 358, Example 10.8.

RQ: Is there a relationship between oral contraceptive use and myocardial infarction?

Step 1: Create Variables

a. Start SPSS.

b. Click the Variable View Tab.

c. Enter the variables MIstatus, OCuse, and frequency.

d. Click the values cell column.

a. Click the push button ellipsis.

b. Enter 1 to the right of value and MIstatus to the right of label; enter 1 =

Yes and 2 = No.

c. Click Add.

d. Enter 2 to the right of value and OCuse to the right of label;

enter 1 = User and 2 = Non-user.

Step 2: Create the Data

a. Click the Data View tab.

b. Enter the values.

Step 3: Analyze the Data

I. From the menu bar, select Data>Weight Cases.

A. The Weight Cases dialog box opens; select weight cases by frequency by moving frequency into the Frequency Variable box.

B. Click OK.

C. The Crosstabs dialog box opens;

a. Select OCuse and move it into Row(s) box.

b. Select Mistatus and move it into Co/um/3(s) box.

c. Click the Statistics button; in the Crosstabs: Statistics dialog box, click Chi-square, Risk, and Cramer's V.

d. Click Continue.

e. Click Cells: under Counts, select Observed and Expected and under Percentages select Row.

f. Click Continue.

g. Click OK.

Step 4: Interpret the Results: Chi square [continuity correction] = Relative Risk = 95% Confidence Interval =

Summary of Results in APA Format: