Monday, August 10, 2020

Tests

America has essentially given up on containing the corona virus, and will just let it spread while we await a vaccine. Oh sure, our governors and other public officials flap around about wearing masks and social distancing. But there is no serious public health effort. (If you're in California, I encourage you to listen to NPR's faithful coverage of our Governor Gavin Newsom's noon daily press conference. Never has anyone so artfully said so little in so many words.) 

A vaccine is a technological device that, combined with an effective policy and public-health bureaucracy for its distribution,  allows us to stop the spread of a virus.  But we have such a thing already. Tests are a technological device that, combined with an effective policy and public-health bureaucracy for its distribution, allows us to stop the spread of a virus. 

For that public health purpose, tests do not need to be accurate. They need to be cheap, available, and fast. When the history of this virus is written, I suspect that the immense fubar, snafu, complete incompetence of the FDA, CDC, and health authorities in general at understanding and using available tests to stop the virus will be a central theme. (Well, forecasting historians is a dangerous game. Already "the virus increases inequality and social injustice" seems to be the narrative of the day.) 

Marginal revolution has three insightful posts on the issue. "Bill Gates is angry" starts with a  comment on the fact that currently, once you get a test, it can take days or even weeks to get the results.  

..that’s just stupidity. The majority of all US tests are completely garbage, wasted. 

If the point of the test is to find out who has it, and isolate them, then an answer that comes back after they've gone out to spread the virus to friends, family and co-workers is completely wasted. Gates has an econ-101 insight into why this is happening:

If you don’t care how late the date is and you reimburse at the same level, of course they’re going to take every customer...You have to have the reimbursement system pay a little bit extra for 24 hours, pay the normal fee for 48 hours, and pay nothing [if it isn’t done by then]. And they will fix it overnight.

I know a great such reimbursement system, but I'll hold that in suspense. (You can probably guess what it is.) 

A second great insight: 

"Stack push-pop testing" or LIFO (last in, first out).  Currently labs work on a first come first served model. New samples are pushed to the back of the line. Well, that's only fair, you say. But when the lab is backed up a week, it means that none of the tests are useful. Instead, labs should simply throw out any samples that are more than, say, two days old, and do the most recent samples first. 

just as many tests will be completed as under the current model but the tests results will all come back faster and be much more useful. ... faster, more useful tests will help to end the crisis by reducing the number of infections.

My emphasis. This is of course what labs would do if they faced the economic incentive suggested by Mr. Gates. 

The central problem, I think, is conceptual. What are tests for? Well, there are two answers. A test can be useful to help doctors to evaluate an individual patient, and decide what treatment is appropriate. Or a test can be useful to public health authorities, to businesses, to people, to sports teams, to airlines, to bars and restaurants to find and isolate people likely to be sick, and to clear people not likely to be sick for public interaction. The requirements for speed, cost,  and accuracy those two purposes are radically different. Exhibit A is group testing. Group testing is not a good solution when there is one patient in an emergency room. Frequent repeated group testing is ideal if there are 100 employees, school children, airline passengers, etc. that you want some probabilistic assurance are not likely to have the virus. 

This conceptual hurdle, I think, lies behind the FDA blocking saliva tests, for example. MR makes this and other key points in Rapid tests


A test that isn't very good at picking up people with small viral loads, but gets answers back quickly is better than a test that is more sensitive and gets answers back in a week. The same point goes for a test that is cheap and lots of people will take, one that you can get without an expensive doctor referral and prescription, and a test that is half as accurate but twice as many people take it -- for the purpose of public health. Again, the purpose of stopping contagion is different from the purpose of diagnosing and treating a given sick patient. The FDA seems only to understand the latter, not the former. When did "how fast can you get test results back?" enter its calculus for certification?

Alex Tabarrok on MR: 

I do think we are beginning to see some recognition of the difference between infected versus infectious and the importance of testing for the latter. What is frustrating is how long it has taken to get this point across. Paul Romer made all the key points in March! (Tyler and myself have also been pushing this view for a long time).

In particular, back in March Paul showed that frequent was much more important than sensitive and he was calling for millions of tests a day. At the time, he was discounted for supposedly not focusing enough on false negatives, even though he showed that false negatives don’t matter very much for infection control. People also claimed that millions of tests a day was impossible (Reagents!, Swabs!, Bottlenecks!) and they weren’t impressed when Paul responded ‘throw some soft drink money at the problem and the market will solve it!’. Paul, however, has turned out be correct. We don’t have these tests yet but it is now clear that there is no technological or economic barrier to millions of tests a day.

Go yell at your member of Congress.

Again my emphasis for a nice epigram. I like Alex's optimism. Your member of Congress has left town, unable to agree whether to only shower the electorate with $5 trillion of newly printed money, or $7 trillion, and how much pork to larder in with that. 

What's a better reimbursement model? That tests for covid-19 are shoved through America's uniquely dysfunctional health insurance system is ridiculous. How about a free market? People, organizations, and businesses should be able to buy freely, without prescription, any test that anyone wants to sell them. Will some tests be less than perfect? Yes, but there are lots of ways of getting information about which tests work. Why is a covid-19 test more regulated than a pregnancy test?  Why is one an expensive and time-consuming prescription, insurance, referral product and the other not? I guarantee you lots of tests, much faster results, and a quick end to the virus. Sure, "can't afford..." So let the market operate on top of the insurance system. 

Of course as for paying, there is a good case that the government pay for any tests anyone wants. National weekly testing would be a lot cheaper than $5 trillion. Again the purpose is public health, a classic public good. But the price signal that we only buy your tests if we like the results, the accessibility, the customer service, the speed, are important. Allowing a cash option on top of the usual bureaucratic snafu would solve the problem quickly. Yes, some people can't afford. But there are lots who can, and they spread the disease just as much as those who can't!

In the meantime,  we're back to the Middle Ages. I note governors imposing quarantines. All travelers from "high infection" areas must self-quarantine for two weeks. Unlike in the Middle Ages, nobody is enforcing this sort of ban, so all it does is to force law abiding businesses to close, and further kill airlines and hotels. (Colleges that could handle on-campus restarts, for example, are going online because they can't let students travel to get there.) Ah, dear governors, have you heard about tests? How about when you step on a plane we all spit in a bucket, and a group saliva test clears everyone -- or not, in which case each individual gets a test. 

So we wait for the vaccine. But vaccines also -- maybe even more than tests -- require a competent public health bureaucracy if they are to be used to stop a pandemic. Who will pay? Which vaccines get to be sold? How hard is it to get one? Who gets it and when? The vaccine does not just protect you, it protects all the people you want to infect. Properly using a vaccine to stop an epidemic is not an immensely simpler bureaucratic and public health challenge than properly using tests to stop an epidemic. Will our public health bureaucracies do much better next time around? 

34 comments:

  1. You blame the CDC, the FDA, and general health authorities for the snafu. Yet you fail to direct blame to Trump and the White House. Why?

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    1. Because he is not a deranged partisan whose every waking thought is about how much he hates Trump. I.e. he is not a CNN/MSNBC talking head.

      I will freely admit that Trump has no understanding of the pandemic, nor of the Federal Bureaucracy that he is supposed to manage.

      Of course, neither does the other guy.

      https://www.amazon.com/VIBE-INK-Everybody-Screwed-Political/dp/B07SKZDK2G/

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    2. I really like Cochrane, but it seems to me HE is being partisan. Objectively, you can direct much more blame to the White House than the CDC. The White House effectively prevented the CDC from doing their job since March. The irresponsable and uncoordinated opening up the country, that haphazard policy on masks. All of that blame lays on the White House, and those are very important things that John did not even mention.

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    3. Pabloria - easy answer: the President - any president (and not only the president, members of Congress, too) - gets its info from the "experts" in government. Those experts reside in the CDC, FDA and other general public health authorities.
      What you fail to see is that no politician from any party are experts on anything, they take advice from the experts that surround them - again, those are the CDC, the FDA, the NIH, and others.
      Thus, Pelosi and Schumer are no experts either. And neither is Joe Biden.

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    4. So the captain of the plane is shooting randomly at the cockpit instruments, totally out of control, and you want us to believe that it's partisan to blame him, remove him and stop the plane from crashing?? Wow! Rationality is just out of the window it seems ... sad. What do think if any other administration lost > 1 trillion a month, when the solution in March was to test test test (as John has written many times)?

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    5. CDC and FDA take the information and ideas from WHO. And WHO has been taking the command from Beijing. WHO and Beijing government together deceived the whole world on the truth of this virus. Do you hear anybody from CDC or FDA say anything negative about WHO or Beijing government? WHO and FDA published negative information about HCQ and put restriction on the use of it based on false research articles. When these article were retracted, FDA and WHO still hold their "official" opinions on HCQ.

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  2. Governance question: No doubt that CDC and other agencies failed miserably. Why do you think that occurred? Is it the people who work there, some systemic reason, both, or something else? Thanks.

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  3. To be brief, testing sucks and what you're proposing is that a lot of bad data is better than no data.

    I just lost a friend to Covid. In late July she developed a cough and fever. Her doctor did a rapid test which was negative. He repeated it, negative. He said he didn't believe the results and ordered the PCR test, also negative. While she was in the hospital she tested positive. She died over the weekend. What difference did testing make?

    When I was training residents at Duke one of the things I beat into their heads was before you do a test, ask yourself what you'll do if it's positive and what you'll do if its negative. If the answer is the same, don't do the test.

    So far I've had 2 patients who were positive, both asymptomatic nursing home patients who get tested regularly as part of the care protocol. At the time I saw them, both were negative within the past few days. The day after the visits the nursing homes called to notify us that their later tests were positive. What did I do with this information? Nothing, because I assume that everyone i encounter is infected. It's called "universal precautions".
    PCR appears to test positive when people are shedding dead virus.

    Does positive serology indicate immunity? People talk about immune memory but how many colds have you had during your lifetime? Were they all the same coronavirus? Different strains like influenza?? Nobody knows.

    How can you possibly use these tests? It simply isn't actionable information.

    But hey, it has spurred something near and dear to your heart: lots of capital being spent to compete in the free market to find a vaccine or cure, none of it coordinated by the government, but then you bitch about the failure of the government to organize a response. And nobody can agree on the response. There's the Sweden debate, and then you have the Dutch, who don't recommend or require masks due to lack of scientific evidence of effectiveness. How do you take a scientific approach without adequate science?

    "But vaccines also -- maybe even more than tests -- require a competent public health bureaucracy if they are to be used to stop a pandemic." So now you want bureaucracy?


    Oh wait - no you don't. "How about a free market? People, organizations, and businesses should be able to buy freely, without prescription, any test that anyone wants to sell them. Will some tests be less than perfect? Yes, but there are lots of ways of getting information about which tests work. Why is a covid-19 test more regulated than a pregnancy test? Why is one an expensive and time-consuming prescription, insurance, referral product and the other not? I guarantee you lots of tests, much faster results, and a quick end to the virus. Sure, "can't afford..." So let the market operate on top of the insurance system."

    Will the real John Cochrane please stand up? Or maybe at least the one who understands that testing is not as simple as it sounds?

    How effective are vaccines? Polio, DPT, measles, etc have been winners. Flu vaccines not so much. Where's the HIV vaccine? Its been 40 years. Ebola vaccine?

    Coronavirus vaccines are very difficult to develop, as in "No one has ever been able to make one, even though they are common causes of colds".

    There are no drugs that can kill coronavirus. Medication is what has decreased mortality due to AIDS and hepatitis C.

    The virus is highly contagious and asymptomatic carriers abound. Unlike HIV, you don't have to work hard to catch it.

    Summary:

    No vaccine.
    No cure.
    Testing is difficult to interpret.
    Highly contagious.
    Very little useful data.

    Conclusion: This is mental masturbation. Debate all you want, but silly ideas like spitting in a bucket before boarding a plane are really just worth a bucket of spit.


    Keep working from home Dr. Cochrane. Those of us at high risk, over 65 with respiratory disease, will pick up the slack for you when we go to the office to treat sick people and have to make the hard decisions.

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    1. And yet some countries seem to have got it under control. That suggests Cochrane is right — the US health system has badly messed things up.

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    2. Hi Michael: For purposes of public health, bad data IS better than no data. With more timely and targeted testing using strategies which John Cochrane highlights, more asymptomatic carriers can quarantine. With more asymptomatic carriers quarantining, the number of cases generated by one case will go down. Ideally, less bartenders will superspread the disease to whole restruants and less travelers can seed new infections. The altnerative, is to conintue the accept-a-depression approach as we await a vaccine, which as you point out may not come. Some false negatives may lead to asymptomatic spreaders, but those individuals would have acted the same without the test. Some false positives will lead to individuals quarantining who are not sick, but this seems a much better altnertive to the current rampage of asymptomatic carriers and to keeping 300 million people at home.

      I hope you stay safe and well in these challening times.

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    3. We've seen this picture before--it was originally believed that children weren't susceptible to the SARS-CoV-2 virus, and that young adults were unlikely to require hospitalization if they contracted the virus and developed COV-19 respiratory disease. Both beliefs have turned out to be unfounded, but both beliefs have had a negative behavioural effect on containment of the virus.

      The "some countries seem to have got[ten] it under control[]" also turns out to be an unfounded belief--New Zealand touted itself as "virus-free" last week, this week Aukland, NZ, is poised to go into deep lock-down for three days commencing today (Wednesday in NZ) to identify the sources (4 individuals in one family) and trace contacts, etc. Others, such as France, thought that it had the upper hand over the virus--turns out that that was simply a misapprehension by the political class in that country.

      Dr. Gorback, a medical man and practitioner, has sized the situation up correctly. Dr. Cochrane, an economist and an academic, is addressing an altogether different issue, namely, how should the social planner establish an optimal economic plan to return the economy to its pre-COVID-19 growth track. Of the two, the medical man and practitioner is the more practical, of necessity--lives depend on the decisions he makes. The economist and academic moves in the world of economic theorism and econometric modelling, and lives don't depend on the decisions he makes, a.s. We need both men, and both perspectives. But let's keep their respective roles in proper proportion--give the medical man his due and learn from his insights; prompt the academic to refine his initial "Hail Mary" plan in light of the medical man's practical knowledge. Thesis and anti-thesis, leads to synthesis--according to a respected social scientist of my early acquaintance. Dr. Cochrane is to be congratulated on prompting this discussion.

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    4. Andrew, your summary was really good. Helped me to much better understand what Cochrane was saying.

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    5. Regarding to what Old Eagle Eye said: " The "some countries seem to have got[ten] it under control[]" also turns out to be an unfounded belief", I have a few to say:

      Taiwan indeed got it "relatively" under control: They don't impose any city lockdown since the beginning, they don't have community outbreaks/local cases for a long period of time.

      What they do is: strict border control and contact trace. A mandatory 14-days quarantine for every entrants, and if cases are found, all contacts(including those sitting in the close quarter in flight) would be closely monitored.

      It is at expense of those who coming into the county, and it is, some argues, violation of freedom and rights.

      However, it is also a cost-benefit choice: the government decide expose no risk for the public.

      I am not saying this measurements are applicable for other countries, since everyone is in different stages of pandemics.

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    6. Sorry for your loss, Dr. Gorback.

      Re "When I was training residents at Duke one of the things I beat into their heads was before you do a test, ask yourself what you'll do if it's positive and what you'll do if its negative. If the answer is the same, don't do the test."

      The answer is the person who is positive test self quarantines for 14+ days, the person who tests negative doesn't. That's how you get transmission down. Simple as that.

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    7. Thanks Manfred. As I've learned from Cochrane, "clutter is the disease of American writing." You'll have to excuse the above spelling typos, hammered out on an iPhone, apparently before enough cups of coffee!

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    8. "Coker: And yet some countries seem to have got it under control."

      Bad analogy. The US is more like the continent of Europe than any individual country in Europe. The experience of New York has been very different than the experience of Ohio.

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    9. Michael Gorback, you make a lot of sense. Are you writing about this anywhere else, such as a blog?

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    10. Old Eagle writes: "We've seen this picture before--it was originally believed that children weren't susceptible to the SARS-CoV-2 virus, and that young adults were unlikely to require hospitalization if they contracted the virus and developed COV-19 respiratory disease. Both beliefs have turned out to be unfounded,"

      The second belief is extraordinarily well-founded. Old Eagle is simply wrong and apparently hasn't looked at the statistics regarding this point. Rates of hospitalization and death from COVID-19 are heavily age-stratified. 31.5% of the US population is under 25 years old, and that age cohort accounts for 0.2% of U.S. reported COVID deaths. Some anecdotal news reports about tragically unfortunate outliers don't change those statistics.

      The first one is a bit more complicated. I never saw any claim that children weren't susceptible at all. There were some early one who believed that they're less susceptible to infection, which seems to be true. If anything, early assumptions by other people were that this virus would be similar to flu, where children are a major vector of transmission and are somewhat more at risk than immediately older age cohorts (i.e., people in their 20's). In fact, children are at less risk than the older group. The strong likelihood is that COVID deaths among children ages 5-14 (27 total in the U.S. at the time that I'm writing this) will be less this year than deaths from seasonal flu in that age range.

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  4. It seems there is a slice of the population with an invulnerability complex and refuse to contribute to the maintenance of public health. Time for fines or other punishments for refusing to help. What good are tests if people don't change their behavior, hmmm? We need sane testing and behavior modification.

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  5. I always enjoy John Cochran's excellent posts, even when I disagree. In this case I disagree.

    I think the right response to Covid-19 was no response, other than possibly government funding to enable voluntary sequestering of elderly with comorbidities.

    Yes, I hope we get a vaccine. Meanwhile, lockdowns seem to delay herd immunity.

    About 50,000 people a month in the US die from cancer, often triggered by environmental carcinogens. Yes, we should look at ways to limit carcinogens in the environment, but we do not shut down the economy to obtain that result.

    Moreover, next year another 50,000 Americans will die each month from cancer.

    Once you obtain her herd immunity Covid-19 is no longer a threat.

    Egads, the reaction to covid-19 is borderline hysteria.

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    1. Strongly disagree. Compared to the amount we spend on cancer, spending on testing would be a drop in the bucket and save as many or more lives once you factor in the likelihood annual mutations of the virus that will come when we try to go herd.

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  6. 'Deus ex machina' is the device that the ancient Greek playwrights employed to rescue their dramatic plots from absurdity. The prospect of a vaccine is the present-day equivalent of the Greeks' 'deus ex machina' that will save American society. Testing is the 'second-best' alternative.

    The unfortunate news is that neither will be the life preservative its proponents believe it to be. The vaccine will be late, assuming it arrives at all. Testing will be limited and controversial, as it is now. You can be tested today and given the all-clear in a matter of an hour (say), and tomorrow be infected and not know it for 2-3 days. The test that was done contained no information the moment it was administered--it was simply a picture taken of an instant in time and was void of information about the future. It provided a false sense of confidence. The relief and elation was short-lived. Cui bono?

    What do we know? (1) the virus mutates in the host, (2) vaccine development and testing takes time, (3) a vaccine is developed for a specimen virus, (4) manufacturing sufficient doses requires capital and time, (5) distributing and administering the vaccine requires capital, organization and time, (6) the vaccine will be ineffective on virus populations that don't match the specimen virus, necessitating continual research and development of new vaccines to tackle new specimen virus mutations. 'Deus ex machina'?--infeasible. But nothing is gained without venturing, so venture on!--who knows, we might be lucky.

    The alternative? Live with the virus--let it rip through society winnowing out those most susceptible and least capable of resisting it and apply medications where practicable, and practice triage on the rest. To hold down the cost. Two years at best before the economy recovers. In the meantime, deal with the external threats that have arisen and the internal strife that is pulling the country apart. A tall order, as tall orders go. And not a white hat in view. More's the pity, for all that.

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    1. re "The vaccine will be late, assuming it arrives at all. Testing will be limited and controversial, as it is now. You can be tested today and given the all-clear in a matter of an hour (say), and tomorrow be infected and not know it for 2-3 days. The test that was done contained no information the moment it was administered--it was simply a picture taken of an instant in time and was void of information about the future. It provided a false sense of confidence. The relief and elation was short-lived. Cui bono?"

      You appear to be missing that the tests don't have to be perfect to get transmission down. It's not a binary thing.

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    2. Testing does not "get [the] transmission [rate] down." At best, testing positive for the SARS-CoV-2 virus initiates a period of isolation for the individual who receives a positive return on a test. However, isolation of such individuals is not a given--it depends on the individual and his/her circumstances. The individual's response to a negative test result is to avoid isolation even if symptomatic--the test result "proved" that he/she is not infected, hence free to continue mingling with the population.

      Now, it is perfectly true that individuals that receive a negative test result when they are infected ('false negative') likely do not alter their behaviour after testing, and it is therefore equivalent to not being tested at all. It is therefore contended by some that the test does not make matters worse, that the individual would have infected others even if no test was administered, that an ineffective test is better than no test at all (in the sense that a defective radar system that detects 1 in 20 incoming missiles is better than no radar system at all). The problem with that logic is summed up in an old adage from early days of the age of computers, namely, "Use of a computer allows you to err with confidence." You trust the computer implicitly because you have no capability to determine whether the result that issues from the computer is wrong--"It's a computer!, after all--how could it possibly give a wrong answer?" Well, let's count the ways.

      'Testing' is proposed in Dr. Cochrane's blog as a means to revive the economy and avoid the costs associated with a partial'shut-down' (there hasn't been a complete shut-down and quarantine as yet). And the 'testing' proposed is any old test that anyone could devise, not just the two test types that have received conditional approval by federal authorities. Furthermore, the 'testing' costs should be borne by the federal treasury on a cost-reimbursement basis for any 'test' irrespective of the efficacy of the 'test'. What could be more fertile ground for shams and frauds and 'snake-oil' salesmen?

      And as I wrote, a 'test' tells you nothing of your condition tomorrow. You have to be tested daily. Assume that 250 million individuals require testing at least once per week for a year, for a total of 13 billion samples requiring analyses. Take $10 per sample, for the marginal cost, to arrive at $130 billion per year. It's less than $2 trillion expended in six months, certainly. And less than the $2.8 trillion that the Democrats in Congress want to spend in the next 4 months. But if the tests are ineffective, then all you've done is enrich the promoters of the test and not improved the situation one iota. Ask yourselves, in that case, "Cui bono?"

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  7. "Untangling the Media Myths of Covid-19: They’re countless. States that reporters shamed have done the best, and the U.S. is average among its peers." By Gerard Baker | Aug. 10, 2020
    https://www.wsj.com/articles/untangling-the-media-myths-of-covid-19-11597099357

    * * *

    First, the notion, implicit or at times explicit, in so much of the reporting, that the U.S. handling of the pandemic has been a globally unique failure. ... The death toll in the U.S. stands at around 500 per million people. That is significantly higher than in Germany or Japan, for example, but still some way below the U.K., Italy, Spain and several other European countries. Among the Group of Seven nations, America is right in the middle.

    ... a fair assessment would note the broad similarity in death rates among most large economies and a divergence from the numbers in some of the others, rather than suggesting this is a uniquely American phenomenon....

    ... New York continues to enjoy the dubious record of one of the highest death rates of any region in the entire world. Far from “flattening the curve,” New York, again, did precisely the opposite. It suffered a barely fathomable surge in deaths that overwhelmed much of the state’s medical capacity.

    A related fiction is the suggestion that New York’s economy is now bouncing back as its cases and deaths, mercifully, continue to dwindle toward zero. Yet by the unemployment rate and other measures, the economic recovery in New York is lagging states such as Florida and Texas, with commuters and tourists still staying away.

    We should not fall into the media’s trap of tendentiously asserting a tight link between politics and the virus. ... [there is an] apparently willful refusal to attempt a balanced assessment of the way governments have handled this unprecedented challenge.

    The task all along with Covid wasn’t to extinguish the virus completely. ... The real task was to balance the health and economic risks, knowing that the long-term health costs of economic ruin are likely to be at least as costly as those of the virus itself.

    As we stand, the states that have come closest to achieving this balance are the ones that continue to be denounced in the media: Florida and Texas. Their death rates are below those of similarly populous coastal states, and while deaths continue to rise, it seems that the virus has peaked for now. Florida and Texas have also been among the most successful in keeping their economies from collapsing. As of late July the share of the workforce claiming unemployment benefits was less than 8% in Florida and less than 11% in Texas, well below New York and most of the Northeast. If the right measure of success is minimizing deaths while maximizing growth, Florida and Texas are succeeding on both fronts.

    There are many reasons for differing rates of infection, death and economic performance, and it would be unwise at this stage to say anything about outcomes with absolute certainty. But that is perhaps the greatest dishonesty of all: the media’s self-serving insistence that their narrow, partisan narrative of this complex and evolving phenomenon is the revealed and unchallengeable truth.

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  8. 1.- The situation is not "out of control". In Miami-Dade, arguably one of the hot spots for Covid19 in the country (population 2,7 mill), the number of "admited patients" has gone from 2,079 to 1,623 in the last 15 days, a 22% reduction. The number of covid patients in ICU beds has gone from 549 to 423, a 23% reduction.

    The measures taken: facial coverings and the ban of indoor dinning and big gatherings.Umpleasant but not the end of the world.

    2.- As Benjamin mention in his comment. Covid 19 is bad but not that bad: using again the Miami-Dade case, the number of people testing positive has been (since the begining of the pandemic) 5% of the population, going to a hospital because of Covid 1% of the population, deaths, 0.07%. Most of them (north of 85%) older than 65 or with pre-existing conditions, which means populations at high risk are easy to identify and designing special measures to protect them should also be easy. You have to be alwasy very careful with a contagious desease (it does not compare to cancer or car crashs, it is a totally diferent kind of animal). But the spread is not going exponential right now.

    3.- In reality, so different from theories, you don´t need contact tracers. You have all the right incentives to contact trace yourself: you hear that somebody you have spent time with in the last days or somebody that has spent time with somebody you have spent time with, has tested positive and you get tested in order to decide whether to keep up with your normal life or isolate yourself.

    What do you need at that point?. A web page you can enter and get the earliest possible date for a test in your area and an appointment to get it. And a menu of options price-time to get the test and the results that allows you, depending on your circumstances (are you travelling?, are you visiting your parents?, or live with them) decide what kind of test you want to get.

    This is not what you get right now. You get a useless free test with the same waiting time period for everybody (1-2 days to get the appointment and 4-5 days to get the results on average). Which is totally nonsense but extremely egalitarian. 6 months into this problem, why you still don´t get what you need?

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  9. As a researcher in mathematical epidemiology who works on stochastic propagation models, this post overestimates what testing can accomplish. Yes, testing is important and yes we need to do far more of it in a far more timely fashion, but testing is not an eradication strategy. While aggressive rapid testing can help bring a local outbreak under control, and thereby protect the healthcare system, it cannot eradicate the disease from the wider population. The only way that a contagion such as Sars-CoV-2 can be stopped is by reducing the susceptible population either by a vaccine or by exposure to the pathogen itself.

    Imagine that we rolled out a massive testing program across the country as suggested in this blog post. Even if we could test every American all the time and isolate, unless you are prepared to do that level of testing essentially forever, Covid-19 will re-emerge from a foreign source at some point and it will then begin to propagate much like it did in March. It doesn’t take many infected people in a susceptible population to get the Covid-19 train rolling and you are right back to nationwide testing. But in practice, no matter how hard we try, a sizable fraction of the population, probably in the neighborhood of 20%, would never be tested. Think about how hard it would be to get near 100% compliance on a continued testing program across the entire country. Think about the enforcement that would be required not only for the testing itself but for those who refuse to follow quarantine orders from failing to get a test. In the end, that strategy would maintain a large susceptible population within the country in proximity to an infected population. The contagion will constantly be trying to find a way in. It’s more than wack-a-mole, it’s Pokemon — you gotta catch’em all.

    This respiratory disease is with us for good now. Testing and isolation is brittle as an eradication strategy for a globally widespread highly contagious pathogen; it simply maintains a susceptible population. Testing works to help bring local outbreaks under control, but only by reducing the susceptible population can we achieve anything close to eradication.

    As the eminent epidemiologist Johan Giesecke pointed out, “Everyone will be exposed to severe acute respiratory syndrome coronavirus 2, and most people will become infected. COVID-19 is spreading like wildfire in all countries, but we do not see it — it almost always spreads from younger people with no or weak symptoms to other people who will also have mild symptoms...COVID-19 is a disease that is highly infectious and spreads rapidly through society. It is often quite symptomless and might pass unnoticed, but it also causes severe disease, and even death, in a proportion of the population, and our most important task is not to stop spread, which is all but futile, but to concentrate on giving the unfortunate victims optimal care.”

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    1. re " this post overestimates what testing can accomplish. Yes, testing is important and yes we need to do far more of it in a far more timely fashion, but testing is not an eradication strategy. While aggressive rapid testing can help bring a local outbreak under control, and thereby protect the healthcare system, it cannot eradicate the disease from the wider population. The only way that a contagion such as Sars-CoV-2 can be stopped is by reducing the susceptible population either by a vaccine or by exposure to the pathogen itself."

      Do you have any citations that support this?

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    2. This comment has been removed by the author.

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    3. You don´t need to stop the virus. All you need is keep the death and hospitalization rate at a manageable level (like we do with a whole bunch of other contagious diseases, by the way).

      Having the possibility to get a test and the result fast when you think you have been exposed to the virus, is a key element in getting that goal. You don´t need the "test net" to be "perfect" for this.

      You don´t need "perfect" solutions. You have to implement every tool that improves the situation at a reasonable cost. "At demand - fast results - easy to get -widespread" testing is one of these tools.

      Together with facial covering (even it is a low efficiency tool), the ban of big gatherings, the hospitalized treatment improvement and special measures for the most vulnerable, can get the pandemic under control.

      "Perfection" is the enemy of the "good enough". We don´t need "theoretically perfect" solutions. And we do need to remember that there are two kinds of people: the ones that find a solution for every problem and the ones that find a problem for every solution ... the latter ones tend to work for the government and/or in Academia.

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    4. Good work. Excellent thoughts.

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    5. Agreed, testing does not need to be perfect to be effective at taking pressure off the healthcare system. But, as a research in how diseases actually propagate, Sars-Cov-2 doesn’t have much hope of eradication without a massive reduction in the susceptible population. It’s globally widespread and it’s highly contagious.

      What I find confusing about the political and public health response is what we are trying to achieve. Is it that we are trying to maintain the susceptible population in hopes of a forthcoming vaccine? Maybe we will get lucky, but a vaccine may not materialize for a long time and it may not be all that effective. The public seems to think that if there is a virus, researchers can develop a vaccine quickly, it’s just a matter of effort. That’s not true. HIV/AIDS still does not have a vaccine despite the effort. Lots of virus that affect humans have no vaccine. Is it that we are we trying to eradicate the disease by testing, etc.? That is impossible at this point. Using testing in an attempt to eradicate is a Sisyphean task.

      There is only one course of action that really makes any sense to me and it is what will happen almost certainly regardless. Recognize that Covid-19 is with us to stay, just like the flu, STDs, and other communicable diseases. We need to protect our healthcare system and vulnerable people. Let’s concentrate our resources there, then, allow the virus to spread through the population, which is inevitable at this point. All we get to choose is the time scale on which to reduce the susceptible population – years of Covid-19 protocols or something much less.

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    6. I am undecided on this--but some observations & thoughts:
      1) No other country has been reported to have implemented the strategy proposed in this piece. Why would this be if the FDA were the problem.
      2) Backers have published no real data showing level of detection (minimum viral load detected), sensitivity at their targeted viral load, and how they did such a study.
      3) What compliance rate would we get from people in self-administering the test daily?
      4) Even among those who comply, what fraction would do it correctly? It may seem simple, but picture asking people to spit on the right part of the strip and wait 10 minutes for the color line to appear. Do you think some will just "guess" when 10 minutes are up and only wait 5? Or maybe forget and check after 20?

      6) The FDA asks for 80% (note this is "guidance" not hard and fast) sensitivity. Suppose they achieve 70% sensitivity, but only 50% of the people use it correctly. You catch only 35% of the cases.

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  10. "COVID-19: Lock-Downs, or Cock-Ups?" by Neil Lock | August 11, 2020 | https://wattsupwiththat.com/2020/08/11/covid-19-lock-downs-or-cock-ups/

    Conclusions

    Of all the countries, the Icelanders and Faeroe Islanders got closest to right in deciding what to lock down. And the Swedes, too. You can ask: Did the Faeroe Islanders need to close all schools, when the Icelanders didn’t? Or, did the Icelanders need to close some workplaces, when the Faeroe Islanders didn’t? But these are quibbles.

    It appears to me that only four of the lockdown measures, which have been used, have been proven effective. In increasing order of stringency to ordinary people:

    Screen arriving international travellers, and quarantine, or at need ban, those from high-risk areas.
    Ban football matches, public parades and large events, at which thousands may gather.
    Restrict the number of people who may assemble in one group, or at a small event.
    As an absolute last resort, confine people to their homes for a short period, with exceptions like shopping and exercise.

    The effectiveness of anything beyond these four is unproven. The pain, though, is obvious.

    As to relaxing lockdowns, three cheers for Luxembourg. Who, unlike many other governments, have approached the whole matter with commendable common sense.

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