Question

To determine whether baldness causes coronary heart disease (CHD) in men, a hypothetical cohor study was carried out. The epidemiologist in charge of the study recruited 10,000 bald men and 10,000 men with hair into the study and followed all of them for 10 years to determine whether they developed CHD. Results are shown below. CHD Yes No Total 775 9,225 190 9,810 965 19,035 20,000 Bald (exposed) Hairy (non-exposed) Total 10,000 10,000

(a) What is the relative risk of CHD associated with baldness? In one sentence, interpret this relative risk. --> 4.08

What is b in this situation?

(b)  Does this result suggest that baldness may be a cause of CHD? Why or why not?

Answer 1

A relative risk > 1 suggests an increased risk of that outcome in the exposed group

This suggest that baldness may be associated with an increased risk of CHD.

Case (Yes) Exposed C Bald) 9 225 775 Hairy Cnon exposed) C. 9 & lo lo, o oo 190 19,035 20, D o c 9 65 total 1 000 o AtB . 019 9 o o, ooo c-t k-t-4.09) Relative Ris D a3e y times This means those Who have CH highenisk a getting bald as comp ad don"4 have c HD. to-those-一who