Statistics and risk
Baseline risk
The starting risk of an outcome before an intervention, exposure or comparison is considered.
What it means
Definition
Baseline risk. Baseline risk determines how meaningful a relative change is. The same relative risk reduction has a larger practical impact in a high-risk population than in a low-risk population.
What it can tell you
It can show whether a result is being framed as a proportion, percentage or real-world difference.
What it cannot tell you
It cannot show whether the effect is important unless the baseline risk, population and outcome are clear.
Headline trap
Why this matters in headlines
A 30% reduction matters more when the baseline risk is 30% than when it is 0.3%.