Statistics and risk

Statistical significance

A threshold-based label suggesting a result is unlikely under a specified no-effect model.

What it means

Definition

Statistical significance. Statistical significance is often treated too strongly in headlines. It does not prove causation, clinical importance or reproducibility, and it depends on the chosen threshold and analysis plan.

What it can tell you

It can help clarify what sort of evidence or claim is being discussed.

What it cannot tell you

It cannot, by itself, prove that the headline is accurate or clinically important.

Headline trap

Why this matters in headlines

A statistically significant biomarker change may not translate into fewer symptoms, admissions or deaths.