If a relative risk is 1.5, what does this mean for exposed vs unexposed?

If a relative risk is 1.5, what does this mean for exposed vs unexposed?

• A. Exposed have the same risk as unexposed.
• B. Exposed have a 100 percent higher risk than unexposed.
• C. Exposed have twice the risk of the unexposed.
• D. Exposed have a 50 percent higher risk than unexposed.

Answer: (D)

A relative risk of 1.5 means the risk in the exposed group is 1.5 times the risk in the unexposed group. That translates to a 50% higher risk for the exposed group, because 1.5 is 0.5 more than 1.0 and 0.5/1.0 equals 50%. For example, if the unexposed risk is 4%, the exposed risk would be about 6%. A relative risk of 1 would mean no difference between groups, and a relative risk of 2 would mean the exposed have twice the risk (100% higher).

A relative risk of 1.5 means the risk in the exposed group is 1.5 times the risk in the unexposed group. That translates to a 50% higher risk for the exposed group, because 1.5 is 0.5 more than 1.0 and 0.5/1.0 equals 50%. For example, if the unexposed risk is 4%, the exposed risk would be about 6%. A relative risk of 1 would mean no difference between groups, and a relative risk of 2 would mean the exposed have twice the risk (100% higher).