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United States Government Medicine Stats

America's CDC and 11 States Erroneously Conflated Two Kinds of Coronavirus Tests (theatlantic.com) 118

America's Center for Disease Control "is conflating viral and antibody tests..." writes the Atlantic, "distorting several important metrics and providing the country with an inaccurate picture of the state of the pandemic."

Thelasko shared their report: We've learned that the CDC is making, at best, a debilitating mistake: combining test results that diagnose current coronavirus infections with test results that measure whether someone has ever had the virus. The upshot is that the government's disease-fighting agency is overstating the country's ability to test people who are sick with COVID-19... The widespread use of the practice means that it remains difficult to know exactly how much the country's ability to test people who are actively sick with COVID-19 has improved.

"You've got to be kidding me," Ashish Jha, the K. T. Li Professor of Global Health at Harvard and the director of the Harvard Global Health Institute, told us when we described what the CDC was doing. "How could the CDC make that mistake? This is a mess...." By combining the two types of results, the CDC has made them both "uninterpretable," he said...

[T]he portion of tests coming back positive has plummeted, from a seven-day average of 10 percent at the month's start to 6 percent on Wednesday. "The numbers have outstripped what I was expecting," Jha said. "My sense is people are really surprised that we've moved as much as we have in such a short time period. I think we all expected a move and we all expected improvement, but the pace and size of that improvement has been a big surprise."

The intermingling of viral and antibody tests suggests that some of those gains might be illusory.

"The CDC is not alone in its errors," notes a Reason article shared by schwit1. "Several states have been blending their test results as well, rendering it difficult to determine the local impact of the virus." But the CDC's role as the officially designated first line of defense makes the agency's failure far more significant. Without clear, reliable, and accurate reporting from the CDC, it becomes nearly impossible to take stock of the pandemic's damage.

The virus has upended American life in ways that make it unusually difficult to predict the future. But thanks to the CDC, we have a problem that is even worse: No only do we not know what is going to happen, but we don't know what is happening.

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America's CDC and 11 States Erroneously Conflated Two Kinds of Coronavirus Tests

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  • Accidental? (Score:5, Insightful)

    by nicolaiplum ( 169077 ) on Saturday May 23, 2020 @05:42PM (#60096320)

    You think it's an accident that these statistics have been confused enough that you can't tell how well the US is doing at detecting and handling current cases - at a time when many vested interests care more about supporting their decisions than basing those decisions on facts?

    You really think this is an accident?

    Then I have some prime beach land to sell you in Florida. It doesn't even have an outbreak of pandemic coronavirus nearby.

  • ...or so somebody said.

  • by Solandri ( 704621 ) on Saturday May 23, 2020 @05:46PM (#60096340)
    My brother-in-law took a Covid-19 antibody test, and it came back positive. Which led to a small panic in our family as my sister and their kids had thus far remained virus-free. Upon reading the fine print [covid19testingkits.org] for the test, I came upon this gem:

    Limitations: "Positive results may be due to past or present infection with non-SARS-CoV-2 coronavirus strains."

    So the antibody tests don't just return a positive result for Covid-19 (official name is SARS-CoV-2), they can return a positive result for a variety of coronaviruses. So its dangerous to use the antibody test results as an indicator of how widespread Covid-19 is among the general population [usc.edu].

    Based on the antibody test, my BIL got fast-tracked for a regular Covid-19 test, and came back negative. So either the antibody test was erroneous, or it was picking up a different coronavirus infection. (Or he really is infected and the second test was a false negative, but my sister and kids are fine so it's probably accurate.)

    • When about 20% of "common cold" cases are caused by a different coronavirus, you have a lot of people have "past infection with non-SARS-CoV-2 coronavirus".
      This test sounds like it is useless. Use a highly specific test (such as the one developed by Roche and currently being deployed in the UK health service).

    • by raymorris ( 2726007 ) on Saturday May 23, 2020 @06:20PM (#60096494) Journal

      Suppose the test is 95% accurate in that only 5% of people who are actually negative get a positive result. If that were the case, about half of the positive tests would be people who are actually negative.

      How the heck can that be true, you might ask. How is "95% accurate" only 50%?

      Prior probability is why. Suppose 1,000 random people are tested. The test will erroneously say 50 positives for people who are actually negative. Suppose 40 of 1,000 are actually positive. The 95% accurate test will find the 40 true positives and 50 false positives.

    • by hey! ( 33014 ) on Saturday May 23, 2020 @06:45PM (#60096602) Homepage Journal

      This is why test approval usually takes a long time. We're talking about "antibody tests" as if they're all the same thing; in fact there's dozens of of antibody tests that have been rushed to market and they have wildly different levels of sensitivity and selectivity.

      I personally would not have an antibody test because of exactly the scenario you describe. In isolation, even a test with good selectivity and sensitivity isn't going to yield any useful information. If your test is positive, and you have no other reason to think you have COVID-19, chances are that it's a false positive.

      If, on the other hand, the test is negative, that doesn't mean you don't have it; it's possible you're infected and your immune system hasn't responded yet.

      Antibody tests have their uses,but screening random people isn't one of them.

    • I've been very concerned about this (although theres potentially a silver lining in this).

      Its been well established for a while Coronaviruses seem to display some element of cross reactivity when it comes to antigens

      A paper I found a while back on SARS (published 2005 I *think*) found Sars antibodies reacted with the coronavirus-a common-cold type coronaviruses, and it might be inferred that a reaction the other direction might be the case too.

      In other words, are we *certain* we've been tracking the right a

      • The upside of this: Maybe, just maybe, the humble common cold, well the non-Rhinovirus version, might actually be protective. This *definately* deserves investigation.

        Or the other way around: maybe antibodies for one particular HCov common-cold virus lead to a counterproductive immune-system response, which causes older people (with more lifetime exposure to HCovs) to suffer more.

        Speculation works both ways...

    • by dgatwood ( 11270 )

      My brother-in-law took a Covid-19 antibody test, and it came back positive. Which led to a small panic in our family as my sister and their kids had thus far remained virus-free. Upon reading the fine print [covid19testingkits.org] for the test, I came upon this gem:

      Limitations: "Positive results may be due to past or present infection with non-SARS-CoV-2 coronavirus strains."

      FWIW, the manufacturer of that test claims 100% specificity [healgen.com]. Whether that is accurate or not is another question entirely, but that's their claim. They pretty much have to say that, though, because there's always some possibility that they're wrong, and that it will cross-react with some other coronavirus's IgG/IgM.

      There's also the possibility that some manufacturing mistake could result in pre-contaminated test kits, though admittedly for an immunochromatographic assay, that's probably not nearly as like

    • Ultra tiny nag: Covid-19 is the disease caused by the virus SARS-CoV-2. So no official and unofficial names...
    • So the antibody tests don't just return a positive result for Covid-19 (official name is SARS-CoV-2), they can return a positive result for a variety of coronaviruses.

      A small nit: SARS-CoV-2 (Severe Acute Respiratory Syndrome [caused by] CoronaVirus 2, named after the first human coronavirus identified in 2003) is the virus. COVID-19 (COronaVIrus Disease of 2019) is the disease caused by the virus. Both are "official" names, "the official names COVID-19 and SARS-CoV-2 were issued by the WHO on 11 Februar [wikipedia.org]

  • Way to go America, for giving China more ammo to claim a cover up from the US.
    • The irony being that if this were a lab created weapon from China, deliberately released to torpedo the US or Trump, we're not only letting it happen, we're helping it spread.

      The usual issue with bioweapons like this are that they're impossible to control and as likely to infect the aggressor as the victim, it's a stupid thing to do. But...through sheer incompetence, on an unintentional virus, we're changing that equation. We may actually be a great country to target with bioweapons.

    • China doesn't need any evidence to make shit up. After all, we have China telling us it's under control and not easily passed between humans and the US Army created it and infected some soldiers and sent them to China.

      Oh and they only had 84k cases, total.

      Who gives a shit what China says about anything? Care what they do? Yes, absolutely. What they say about anything? Nope, they have a piss poor track record on even the most basic statistics like their GDP so how can we trust them for important things li
      • Re: Cover up (Score:4, Interesting)

        by The Evil Atheist ( 2484676 ) on Saturday May 23, 2020 @11:22PM (#60097336)
        America has spread its own fair share of conspiracy theories, even by your president.

        People can point to this evidence and say who gives a shit what America says about anything. Their CDC can't even get its own story straight.

        You seem to think America somehow deserves to be trusted without question, yet this kind of thing shows that's far from the case. I mean, even forgetting the old stuff like bullshit intelligence about Iraq WMDs.

        Funny how Americans are suddenly so trusting of their own government's data after this debacle.
    • by makomk ( 752139 )

      As I understand it, China's own testing numbers generally also include antibody tests. For example, when American newspapers ran stories about how they Chinese had already tested several million people in Wuhan and compare this unfavourably to US testing, most of those tests were antibody tests. Though on past form that wouldn't stop China taking these American news articles portraying this as something the US is doing and pointing to them as proof that the US are the ones faking their numbers whilst China

  • Oh, I know (Score:4, Insightful)

    by phantomfive ( 622387 ) on Saturday May 23, 2020 @05:53PM (#60096376) Journal

    "You've got to be kidding me," Ashish Jha, the K. T. Li Professor of Global Health at Harvard and the director of the Harvard Global Health Institute, told us when we described what the CDC was doing. "How could the CDC make that mistake? This is a mess...." By combining the two types of results, the CDC has made them both "uninterpretable," he said...

    The managers at the CDC probably got their MBAs at Harvard Business School, a high government position. So they are capable of managing anything, doing anything, accomplishing anything, including this mistake.

    • This is why managers think you can easily train anyone to be a programmer. They only know from their own degree that you can take any kind of chimp and drill the crap into him.

      They're the best examples for this.

    • "You've got to be kidding me," Ashish Jha, the K. T. Li Professor of Global Health at Harvard and the director of the Harvard Global Health Institute, told us when we described what the CDC was doing. "How could the CDC make that mistake? This is a mess...." By combining the two types of results, the CDC has made them both "uninterpretable," he said...

      The managers at the CDC probably got their MBAs at Harvard Business School, a high government position. So they are capable of managing anything, doing anything, accomplishing anything, including this mistake.

      I have a friend at the CDC and there are two things to note here: What the CDC puts out is being wrangled so much by the current administration that the rank and file employees (read non political appointees) are not happy with the output. The second thing of note is that Harvard is not very well known or regarded in the field of public health

  • by 93 Escort Wagon ( 326346 ) on Saturday May 23, 2020 @06:22PM (#60096502)

    Apparently Deborah Birx was correct.

    Well, when leadership assignments and policy decisions are made with "I want to neuter this government agency as much as possible" primarily in mind, after three plus years no one should be surprised by the results.

  • by Antique Geekmeister ( 740220 ) on Saturday May 23, 2020 @06:30PM (#60096546)

    Most of the people working there are selfless and passionate about their work. But led by a president who is ignorant of risks, who bankrupts his companies with overly optimistic decisions, and who demands personal loyalty over competence, it's unsurprising that their current leader might base his announcements on the "big vision" rather than on medical facts,

  • It's simple: when everything started we didn't have good tests. As things went we started to get better tests and multiple different kinds of tests. What is going on is the CDC is trying to reconciling all the data. If the numbers are out of wack, then have a neutral statistician review the data and come up with real numbers. Maybe things really are getting better?

    • by hey! ( 33014 )

      Err... mixing up virus and antibody test results is a pretty basic mistake. The tests simply tell you different things. If you combine the numbers together, it becomes harder to draw any conclusions from trends in the numbers, particularly if the proportion of tests varies.

      If a number is meaningless, the best statistician in the world can't fix it.

  • by kbahey ( 102895 ) on Saturday May 23, 2020 @07:55PM (#60096798) Homepage

    America needs to revive the CDC [thelancet.com] ...

  • I agree that they shouldn't be conflated, but they should be tracked and counted towards the overall number of tests. Arguably they are no less useful than rt-PCR tests: in both cases you can only stop testing once you have a positive test. Just because your rt-PCR is negative now, doesn't mean it will be negative 6 hours from now. Arguably, seroprevalence tests are _more_ useful in fact, because they routinely show there are a lot more people who had the disease already and didn't even know, and unlike rt-

    • âoeData Pointsâ US in new direction. ASSumption viral and antibody are âoeindependentâ variables is seriously flawed, so improved âoemeasurement system analysisâ changes to examine if co-variant makes perfectly efficient recalibration sense. Refactoring Testing approach to gather both data points together at same point-in-time From same person, while allowing, for continuity reasons, statisticians to âoeback-intoâ prior trend reporting, requires only capturing curr
  • America's Center for Disease Control "is conflating viral and antibody tests..." writes the Atlantic, "distorting several important metrics and providing the country with an inaccurate picture of the state of the pandemic."

    Somewhat OT but I found out recently that CDC is, for some weird reason, correctly styled as plural. For example, despite the plural construction "Centers for Disease Control and Prevention", the Wikipedia article [wikipedia.org] uses singular verb, noun and pronoun forms in describing the agency:

    The Centers for Disease Control and Prevention (CDC) is the leading, national public health institute of the United States. It is a United States federal agency, under the Department of Health and Human Services, and is headquartered in Atlanta, Georgia.

    • I'm not kidding when I say that I think this is the most interesting comment/question. Hadn't crossed my mind before, but now I really want to know why it's plural.
  • We failed to test when it would have helped. And when we finally got around to it, we're using tests on the wrong people. Really, don't bother testing.

    If I sound flippant, let me say we should do testing if important decisions hinged on test results. But there is no decision waiting on test results. It's madness.

  • Virginia was pulling this crap until the Governor, a medical doctor, became aware of it. An official was quoted as saying it was done intentionally to make the numbers look better. These are the people we need to weed out of government.

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