Statistics and risk
Post hoc analysis
An analysis decided after looking at the data rather than specified in advance.
What it means
Definition
Post hoc analysis. Post hoc analyses are exploratory. They can generate hypotheses, but they are less reliable for firm conclusions because the data may have guided the question.
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 headline based on a post hoc finding should be more cautious than one based on the primary endpoint.