Conditional Probabilities: Apply It 1

  • Describe and find conditional probabilities.
  • Understand the concept of independent events.

Is This Trustworthy?

Viruses
Figure 1. Understanding how COVID-19 spreads makes it even more important for medical tests to be accurate, helping avoid false positives and false negatives.

Medical tests designed to detect diseases are not always perfect. Sometimes, people who get tested may be told they have a disease when they do not actually have the disease. Other times, people who get tested may be told they are free of a disease when in fact they have the disease. The goal is for medical tests to be correct as often as possible so that these types of errors are rare.

COVID-19 Test Reliability

Coronavirus disease (COVID-19) is an infectious disease caused by the SARS-CoV-2 virus.[1] Most people infected with the virus will experience mild to moderate respiratory illness and recover without requiring special treatment. However, some will become seriously ill and require medical attention. Older people and those with underlying medical conditions like cardiovascular disease, diabetes, chronic respiratory disease, or cancer are more likely to develop serious illness. Anyone can get sick with COVID-19 and become seriously ill or die at any age. 

The World Health Organization recommended that “Anyone with symptoms should be tested, wherever possible. People who do not have symptoms but have had close contact with someone who is, or may be, infected may also consider testing.”[2]

  1. https://www.who.int/health-topics/coronavirus#tab=tab_1 ↵
  2. https://www.who.int/news-room/questions-and-answers/item/coronavirus-disease-covid-19 ↵