Study design
Cross-sectional study
A study measuring exposure and outcome at a single point in time.
What it means
Definition
Cross-sectional study. Cross-sectional studies can estimate prevalence and associations, but they often cannot establish which came first. This makes causal claims especially fragile.
What it can tell you
It can show how close the evidence is to a real human health outcome.
What it cannot tell you
It cannot prove that a treatment works in people unless human outcome data are available.
Headline trap
Why this matters in headlines
A survey may find anxiety and screen time are linked, but not whether one caused the other.