Study design
Protocol
A pre-specified plan for how a study will be conducted and analysed.
What it means
Definition
Protocol. A protocol reduces the risk that researchers change outcomes or analyses after seeing results. Comparing the published paper with the protocol can reveal selective reporting.
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
If a paper highlights outcomes not in the protocol, the result may be exploratory.