Medical professionals: How accurate are these Covid -19 test

Just stay at home Karen

Allegedly the American tests have a sensitivity of 95%, meaning only 5% of people who have the test and the new coronavirus will test negative (a false negative). The sensitivity will only get better as they refine the tests. American tests are much better than the Chinese tests, whose sensitivity was only around 65-70%.

Specificity is 99-100%, meaning that if you test positive you certainly have the new coronavirus (very low false positive rate).

I've seen studies put the sensitivity as low as 78% for the nasal swab.

LINK

That means there would be around a 22% false negative rate.

edit: that would be for the Chinese test, though. Supposedly the test in the US has higher sensitivity, though this is unproven currently. We don't seem to have a gold standard to compare it to at the moment, so it is all pretty uncertain.

Is there a study that evaluates the sensitivity of the nasal swab test here in the US?

China’s sensitivity was 63%

They think the tests we are using in Minnesota have a sensitivity between 60 and 70%. That means the false negative is between 30 and 40% in Minnesota.

I don’t know about Louisiana though

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hearing some local physicians really questioning the results of people they are confident have Covid-19.

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No you haven’t. My wife is a physician. No one is saying this at all.

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Also hearing repeated stories of people who die from Covid-19 that were negative

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Lol what? They died from it but didn’t have it?

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Is there a definitive test like a blood test or something that just isn’t readily available?

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You think that we have the capacity to test millions of people’s blood samples at labs?

The swab they take is dna. The dna is tested to see if the strain is in your system.

Stay inside a-hole.

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Supposedly the test in the US has higher sensitivity, though this is unproven currently. We don't seem to have a gold standard to compare it to at the moment, so it is all pretty uncertain.

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Yeah I guess we’ll just have to rely on those scientist and what not.

Jesus Christ.

Physicians are absolutely questioning the test. Just because your wife isn’t doesn’t mean others aren’t.

There’s current guidelines set up in Minnesota to basically ignore negative test results if the clinical picture looks like covid, because we’re experiencing around a 30-40% false negative rate here.

Source: am physician in Minnesota

Correct, only with the PCR testing. The sensitivity does not take into account swab technique insufficiency. The University of Washington has a very thorough sampling strategy that I doubt many drive-through swab technicians are using. To do so would cause quite a bit of discomfort to the patient as well as likely sneezing and coughing. Someone getting paid $15/hour may not want to go through the trouble and danger associated with such a thorough technique.

According to the UW website, appropriate swabbing entails the following:

Insert the Minitip flocked swab into the nostril PARALLEL to the palate until resistance is met by contact with the nasopharynx.

Leave swab in place for 2-3 seconds then rotate completely around for 10-15 seconds.

Remove swab and repeat the same process in the other nostril with the same swab.

Source: LINK

Perhaps someone here who was tested can inform us if that is the technique used on them.

Duck you a-hole, I probably know more doctors than you, and I am personal friends with Dr. Chin Yang. Google it.

Thank you to other people that gave some real responses. I was asking because my daughter was exposed, got very ill, was strongly suspected of having Covid-19 but tested negative with government nasal swab, but all her treating physicians are skeptical, and advised us to act as if she had it, as she had all symptoms as there is no way to retest.