1. Below is a table from a hypothetical cohort study of 3,000 cigarette smokers and 5,000 non-smokers following them for the development of coronary heart disease (CHD).

	Developed CHD	Did not develop CHD	Total
Smokes cigarettes	84	2916	3000
Non smoker	87	4913	5000
	171	7829

Question: Calculate the risk ratio using the data presented above.

RR = (87/5000)/(84/3000) = 0.62

RR = (84/171)/(2916/7829)= 1.32

RR = (84/3000)/(87/5000) = 1.61

RR = (84*4913)/(87*2916) = 1.63

2. Which offers the best interpretation of the risk ratio calculated in the previous question? (assume xx represents the correct number)

Group of answer choices

People who smoke are xx% more likley to develop CHD compared to non-smokers.

Subjects with smoking exposure have an incidence of CHD that is xx% higher than subjects without
smoking exposure.

CHD could be prevented or reduced in approximately xx per 1000 subjects who smoke if they did not smoke.

Approximately xx % of the incidence of CHD in subjects who smoke could be prevented or reduced  if the subjects did not smoke.