8. The following table provides data on the development of coronary heart disease in Framingham, Massachusetts after 16 years for men ages 35 - 44 years, by level of serum cholesterol.

PAY CLOSE ATTENTION TO THE WAY THE TABLE IS SET UP!

	Coronary Heart Disease
Serum Cholesterol	No	Yes	Total
>260 mg/dL	343	94	437
< 260 mg/dL	962	109	1,071
Total	1,305	203	1,508

Use these data to calculate therelative riskof CHD, comparing serum cholesterol>260 to those with levels < 260 (the comparison group).

• 2.11
• 0.67
• 2.41
• 0.41

9. Use the data from Q17 to calculate the risk difference per 1,000.

• 113
• 113 per 1,000
• 0.113 per 1,000
• 0.113% per 1,000

10. Interpret the risk difference.

• There were 113 excess cases of CHD among people with high cholesterol (>260 mg/dL) compared to those with low cholesterol (<260 mg/dL)
• There were 113 per 1,000 excess cases of CHD among people with high cholesterol (>260 mg/dL) compared to those with low cholesterol (<260 mg/dL)
• There were 0.113 per 1,000 excess cases of CHD among people with high cholesterol (>260 mg/dL) compared to those with low cholesterol (<260 mg/dL)
• There were 0.113% cases of CHD per 1,000 among people with high cholesterol (>260 mg/dL) compared to those with low cholesterol (<260 mg/dL)