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Old 05-02-2022, 10:24 PM   #371
evman150
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Originally Posted by GGG View Post
If you notice that wasn’t done in Omicron. It was done from sept 2020 to Jan 2021 when assessing the population base that had Covid at that time was far lower.

Also it statements of 50/50 being no better than a coin flip is misleading because you have taken it from being a 1/100 chance that anyone person has Covid to a 50/50 chance that the person has Covid upon positive test. So by rapid testing you have significantly improved the likelyhood of selecting a person who has Covid.

So for a business having a person segregate from critical staff with a 50/50 chance of being positive and having 97 people be true negatives and 1 false negative slip though I have reduced the Covid exposure by half by having 2 people at home.
I take your point on the coin flip thing. You're right, that's a good improvement. However, it may also be the case the reduced sensitivity to Omicron may wipe out most of the "gains" from the greater pre-test probability (community prevalence). Playing around with the calulator I posted, it looks like 0.5% pre-test probability and 90% sensitivity (Delta-ish numbers) are pretty close to 1.5% pre-test probability and 50% sensitivity (Omicron-ish numbers). With 99% specificity, the odds of actually having asymptomatic covid were 31% and 43% respectively.
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