Health psychology/Cognitive biases · Clinical reasoning

Availability

What it means

Judging a diagnosis more likely because it comes readily to mind — typically recent, dramatic or frequently seen cases.

Worked example

Over-diagnosing PE for weeks after missing one.

In the exam

Having recently missed a pulmonary embolism, a doctor now over-investigates every breathless patient for PE, over-weighting it because it is fresh in mind.

What settles it

Availability over-weights what is easily recalled. Representativeness over-weights how well a case fits a textbook prototype.

Classically confused with

Representativeness

Source: Tversky & Kahneman; Croskerry