How Well Do We Understand Probabilities In Medicine?

Posted on:July 21, 2016
Last Updated: November 24, 2023
Time to read: 2 minutes

In his bestselling book, Fooled by Randomness (which was named one of the smartest books of all time by Fortune magazine), Nassim Nicholas Taleb discusses a question that was posed to a group of medical doctors.

A test of a disease presents a rate of 5% false positives. The disease strikes 1/1000 of the population. People are tested at random, regardless of whether they are suspected of having the disease. A patient’s test is positive. What is the probability of the patient being stricken with the disease?

Most doctors answered 95%. Less than one in 5 professionals answered the question correctly.


Fooled by randomness
Taleb, N. (2005). Fooled by randomness: The hidden role of chance in life and in the markets (Vol. 1). Random House Incorporated.