Question

Keep 5 decimal places for intermediate steps and report your final answers in 2 decimal places (6 points)

Table 12-6: Smoking and Coronary Heart Disease (CHD): A Hypothetical Cohort Study of 3,000 Cigarette Smokers and 5,000 Nonsmokers
	CHD Develops	CHD Does Not Develop	Total	Incidence per 1,000 per Year
Smoke cigarettes	84	2,916	3,000	28.0
Do not smoke cigarettes	87	4,913	5,000	17.4

2. What is the RR for CHD among cigarette smokers vs non-smokers? (1 point)

Answer 1

The relative risk is the probability of a condition being developed in a population compared to another, this is usually done were a correlation and a causation has already been found. It establishes only correlation and not causation.

The relative risk is calculated by the following formula

Exposed and condition present = A

Exposed but no condition is present = B

Not exposed but condition present = C

Not exposed and no condition is present = D

Or in other words

In this case

To interpret this result remember that 1 is equal risk, numbers below 1 have less risk and numbers above 1 have more risk.

In this case 0.60919 is the increase of risk, put in percentage is the risk*100

R=0.60919*100= 60.919%

Rounding it up to two decimals

R=60.92%, this means that there is 60.92% of increased risk of developing CDH if you smoke.