“COVID tests are almost laughably unreliable”

That’s the cut-to-the-chase observation of one pundit … and, the WH outbreak appears to support his conclusion.
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Loyal readers know that I’ve been harping from the get-go that the “testing, testing, testing” strategy was haphazard (wrong people being tested) … and potentially problematic (false negatives and false positives).

Well, the chickens have come home to roost … so, maybe the issue will start getting the attention it deserves.

This CNBC headline pretty much sums things up:

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Specifically, the White House has relied on a COVID screening strategy intended to bubble-wrap Trump from the virus.

Staffers, guests and reporters have all been required to be tested for the coronavirus with Abbott Laboratories’ ID Now test before entering White House grounds.

That test is a rapid molecular test that can produce results in as little as 15 minutes.

So, how did the “bubble” get breached?

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The answer is simple: Antigen-type “Rapid Tests” are fast reporting, but they just aren’t very accurate.

Dr. Michael Osterholm of the University of Minnesota told CNBC:

“Up to half of the people who are infected could test negative by that test.”

And, it only takes one false negative to trigger an outbreak.

Ouch.

That obviously has serious implications … not only for Trump and his entourage, but for businesses and schools that are re-opening.

Laboratory-processed COVID tests are more accurate, but it takes days to get results back … often too late for them to be useful, especially since patients might get infected or become contagious between the test and the results.

Antigen tests provide quick results that have a high likelihood of false-reporting.

So, pick your poison: A quick test that’s likely wrong … or a more accurate test that takes too long.

Maybe now, folks will stop focusing on the quantity of tests being done … and start focusing on testing the right people and improving the precision of the tests.

One Response to ““COVID tests are almost laughably unreliable””

  1. Neel Master Says:

    Hi Prof Homa,

    Thought-provoking as always, but there is a piece you’re leaving out.

    Even at “laughable” accuracy, if testing is widespread enough, it could still stop spread.

    Nobel Laureate economist has been working on this view for months. Here is a clip from one of his journal articles:

    “Our model also indicates that unlike sampling-based tests, population-scale testing does not need to be very accurate: false negative rates up to 15% could be tolerated if 80% comply with testing every ten days, and false positives can be almost arbitrarily high when a high fraction of the population is already effectively quarantined.”

    I’d encourage you to read Romer’s blog, particularly this post titled “Even A Bad Test Can Help Guide the Decision to Isolate: Covid Simulations Part 3”

    https://paulromer.net/covid-sim-part3/

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