Jonathan H Chen MD PhD Profile picture
Physician Data Scientist - Stanford Center for Biomedical Informatics Research + Division of Hospital Medicine + Clinical Excellence Research Center
Oct 5, 2018 21 tweets 8 min read
#Tweetorial on #Diagnostics and #Screening interpretation.
An otherwise healthy 40 year old woman comes to you after reading on the internet about a terrible disease that one in a thousand women get, and a highly accurate test that can save her life. The test is over 99% accurate in people with the disease. For those without disease, the test is only wrong 5% of the time.

You order this test and it comes back positive. The woman anxiously asks you, do I have the disease? What is the chance this woman has the disease?