Health psychology/Cognitive biases · Clinical reasoning

Confirmation bias

What it means

Seeking and interpreting evidence that supports a favoured diagnosis while discounting evidence against it.

Worked example

Ordering tests likely to confirm the working diagnosis and explaining away those that don’t.

In the exam

Convinced a patient has gastritis, a doctor highlights every supportive feature and dismisses the exertional pattern and ECG changes pointing to cardiac pain.

What settles it

Confirmation bias selectively GATHERS/INTERPRETS evidence for a held view. Anchoring is the failure to adjust the initial estimate itself.

Classically confused with

Anchoring

Source: Croskerry