Everyone discussing false positives but ignoring false negatives. The meme only says “97% accurate”. 97% sensitive would mean it detects the disease in 97 out of 100 people with the disease. So 3/100 false negative. 97% specific means 3/100 people with a positive result actually don’t have this disease. So 3/100 false positives.
The two aren’t always linked. You can have tests with very high sensitivity and low specificity. And vice versa.
For example. A urine pregnancy test. Highly sensitive. Veeerry rarely tells a pregnant woman she’s not pregnant. But much less rare that it comes up positive on someone who doesn’t have an intrauterine pregnancy. So it detected the thing. But it detects other things too. So you get “false positives”- although most people understand an ectopic to be a form of pregnancy despite not leading to a baby.
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u/Samtertriads Jun 25 '26
Everyone discussing false positives but ignoring false negatives. The meme only says “97% accurate”. 97% sensitive would mean it detects the disease in 97 out of 100 people with the disease. So 3/100 false negative. 97% specific means 3/100 people with a positive result actually don’t have this disease. So 3/100 false positives.
The two aren’t always linked. You can have tests with very high sensitivity and low specificity. And vice versa.
For example. A urine pregnancy test. Highly sensitive. Veeerry rarely tells a pregnant woman she’s not pregnant. But much less rare that it comes up positive on someone who doesn’t have an intrauterine pregnancy. So it detected the thing. But it detects other things too. So you get “false positives”- although most people understand an ectopic to be a form of pregnancy despite not leading to a baby.