You have just finished a health education in-service to the community on the hazards of smoking. A representative of the tobacco industry is present at your in-service and makes the following comment regarding your presentation: "You gave a nice presenta

HOW TO CALCULATE RELATIVE RISK

EXAMPLE:

If you wanted tocalculate the relative risk for pepsi in the table below...

FOOD ITEMS	PERSONS WHO ATE SPECIFIED FOOD	PERSONS WHO DID NOT EAT SPECIFIED FOOD	95% Confidence Interval
	A	B			C	D
	Ill	Not Ill	Total	Attack Rate	Ill	Not Ill	Total	Attack Rate
Chicken	18	15	33	55%	2	15	17	12%	1.2 - 17.7
Potato Salad	16	20	36	44%	4	10	14	29%	0.6 - 3.9
Potato Chips	10	2	12	83%	10	28	38	26%	1.8 - 5.7
Ice Cream	12	0	12	100%	8	30	38	21%	2.6 - 8.8
Cake	16	2	18	89%	4	28	32	13%	2.8 - 18.0
Pepsi	18	20	38	47%	2	10	12	17%	0.8 - 10.5

You would do the following:

1. Identify which columns correspond to the values for a, b, c, d.  The corresponding columns are labeled in black below.

2. Substitute the values for pepsi in these columns into the following formula:

Relative Risk=(a/a+b)/(c/c+d)=(18/18+20)/(2/2+10)=2.8

Therefore, the relative risk is equal to 2.8.