Evidence quality
Recall bias
Bias caused when people remember past exposures or events inaccurately or differently between groups.
What it means
Definition
Recall bias. Recall bias is common when studies ask participants to remember diet, symptoms or exposures. People with a disease may search their memory differently from people without it.
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 case-control study of diet and disease may be weakened if past intake is remembered unreliably.