March 21, 2020


If you were to apply 1,000 COVID-19 tests in schools or in companies to people who say they have a cold, you would find coronaviruses in 5 people, for example. If the “new” coronaviruses are really so important this season, I’d have to find them.
If, as a doctor, you were to examine 1,000 people who have acute respiratory problems (ARE) in your practice, you would probably find significantly more cases (e.g. 15 “positives”), because only people who seek help come into practice because they cannot cope with the disease alone.
If you do 1,000 tests in the emergency room of a clinic for all patients with acute respiratory problems, up to 15% of the tests will be positive (150 cases).

With a limited number of available tests (here ,1000), the greater the proportion of people who show ARE symptoms, the higher the number of people positive to COVID-19 .
When you know that the mortality rate of severe pneumonia patients treated in intensive care is 20-30% in most countries, the alarmist reports from Italy appear in a different light.

Article (in German) by prof. Ulrich Faigle

Read about another famous cognitive illusion, the Monty Hall problem, or how an overwhelming majority of people – experts included – can be plain wrong…