If the risk ratio is 1.5, what does that indicate about risk in the exposed group compared to the unexposed group?

• A. There is no risk in either group.
• B. Risk is 50% higher in the exposed group.
• C. Risk is 50% lower in the exposed group.
• D. Risk is equal between groups.

Answer: (B)

The main idea is how to interpret a relative risk (risk ratio). A value of 1.5 means the risk in the exposed group is 1.5 times the risk in the unexposed group. That corresponds to a 50% higher risk in the exposed group, since (1.5 − 1) × 100 = 50%. For example, if the unexposed risk is 4%, the exposed risk would be 6% (0.04 × 1.5 = 0.06). Remember, this is a relative measure, not the absolute risk; a value of 1 indicates equal risk, while a value less than 1 indicates lower risk in the exposed group.