[isoprophlex]

Going through something like this is very VERY stressful. When you get a negative you immediately forget about it. When you get a positive you die inside. Speaking from experience here.

84% wrong sounds, to me, as an accurate description. Experiencing this from the inside out, only the false/true positive ratio matters. (Given sufficiently low false negative rates, of course)

84% of people whose world is turned upside down are actually getting a wrong diagnosis.

[andreilys]

You’re talking about precision (true positive / true positive + false negative) but that’s only one part of the story.

There is a real human cost to having a child born with a rare genetic disease (and I would argue is immensely more stressful). You can easily adjust the sensitivity to the test but at the cost of detecting actual true positive cases. The correct response to receiving a positive is to do another test to ensure it’s not a false positive.

To say 84% wrong is clickbait and used to elicit a legislative response (FDA regulation), which will help the reporters career.

The actual ratio to tell if something is “wrong” is accuracy (True positive + true negative) / (true positive + true negative + false positive + false negative)

[mnw21cam]

No, precision is true positive / (true positive + false positive).

Your first equation is sensitivity.

[fshbbdssbbgdd]

If you get a negative result and then your child is born with the condition, you won’t forget quickly either.