Relative Risk vs Absolute Risk: Why the Difference Matters

Risk statistics can be accurate while still giving readers very different impressions.

Relative risk describes the proportional difference between groups. Absolute risk describes the actual difference in the number of events.

For example, reducing an outcome from two people in one hundred to one person in one hundred represents a 50 percent relative reduction but a one percentage point absolute reduction.

Both figures can be useful. Reporting them together generally gives readers a clearer understanding of the size of an effect.