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Monday, March 30, 2020

Apples, Oranges, And Powerline

The Powerline Blog is operated by highly credentialed persons--experts, you might say. Pertintently, three of the four regulars are attorneys, trained--one supposes--in evaluating the relevance of facts to whatever position is being advanced. It was with some dismay, therefore that I read a rather silly post at Powerline yesterday: An Optimistic Projection of COVID-19 Deaths [with comment by Paul].

Here is the portion that I found most disturbing:

According to the CDC, these are the principal causes of death in the U.S.:


As you can see, at 81,000 COVID-19 is nowhere near the top of the list. It represents an increase in the “Influenza and Pneumonia” category, I think. But these other diseases take their toll year after year, while COVID-19 will soon fade from the scene. Maybe in a year or two, sheepishness over the current overreaction to COVID-19 will translate into a more appropriate focus on these more important killers.

A quick glance through the list of "killers" shows that apples are being compared to oranges. Consider:

1. Covid19, from onset to death (since we're dealing with "killers") runs a course ranging up to around 2 weeks--give or take a bit. 
2. Except for suicide, most of the listed diseases result from living one's life. Which is to say that to a very great extent they result from lifestyle choices--poor diet over a lifetime and, especially, smoking, etc. As such, to one degree or another most of these diseases can be prevented or delayed. Accidental death can be another exception, although contributory negligence is often a factor. 
3. More often than not these days death from any of these diseases comes after a prolonged interval--years, even decades. One does not contract heart disease one day and die the next week. Heart attacks and strokes are sudden, but are usually the result of prolonged illness--even if undiagnosed. Again, suicide and accident do lead to sudden death. Determined people will kill themselves. 
4. While it's true that outcomes of Covid19 are worsened by the same poor lifestyle choices--poor diet and smoking--those choices are not causitive. Nor is Covid19 a personal choice, like suicide or accidental death (to some degree) when contributory negligence is a factor.

As for the alleged "overreaction" to Covid19, I won't go into the reasons why I maintain that President Trump had good reasons to act as he has--could hardly have acted otherwise. I've covered those issues at great length. However, I recently read a news item that sheds some light on that issue from a logical, if unexpected angle. Apparently, the CDC has documented that flu deaths in the US have plummeted since the onset of "social distancing." This morning I found a graph that, yes, graphically illustrates the effectiveness of social distancing at drastically shortening the flu season as well as lowering the mortality rate and the overall death toll--the squib line at the bottom is this year:







The point? Prevention works! The incidence of serious respiratory disease really can be lowered.

Now, I'm not suggesting that we shut down the economy every "flu season". However, one wonders whether it isn't high time that Americans took the social costs of "flu season more seriously. There are simple prudential forms of social distancing that could prove effective. The use of chloroquine based treatments should also be considered, since research has shown that chloroquine's antiviral properties are not confined to Covid19.

Perhaps, too, it's time for medical "experts" to stop sneering at the widespread Asian practice of "masking up." The CYA crowd at the CDC continues to spout the conventional "wisdom" that "masking up" is not protective as to the mask wearer, but--beyond common sense--there are grounds for questioning that. Below I link two articles that actually go into the data regarding masking, and they find that even homemade masks made from paper towels are surprisingly effective--and surgical masks are virtually as effective as more expensive N95 masks (which only a minority even of doctors are able to don properly). A cultural change? Yes--but maybe it's time:


Masks work! Wear them!

The author begins:

How do we know if masks work? Here are three ways:
* Test in a field setting by running randomized controlled trials during regular influenza season.
* Test at mass scale during a pandemic by looking at epidemiological data.
* Test in a lab setting by making physical measurements of porosity. 
Each method of study carries different limitations.

He proceeds to cover every angle.

A somewhat more technical approach can be found here, but it's highly readable:

FACE MASKS: MUCH MORE THAN YOU WANTED TO KNOW

Some extended excerpts:

2. Are people who wear surgical masks less likely to get infected during epidemics?
It’s unethical to randomize people to wear vs. not-wear masks during a pandemic, so nobody has done this. Instead we have case-control studies. After the pandemic is over, scientists look at the health care workers who did vs. didn’t get infected, and see whether the infected people were less likely to wear masks. If so, that suggests maybe the masks helped. 
... 
Gralton & McLaws, 2010 reviews several studies of this type, mostly from the SARS epidemic of the early 2000s. ... 
Rapid awareness and transmission of SARS in Hanoi French Hospital, Vietnam was conducted in a poor hospital that only had surgical masks, not respirators. In the latter stages of the epidemic, 4 workers got sick and 26 stayed healthy. It found that 3 of the 4 sick workers hadn’t been wearing masks, but only 1 of the 26 healthy workers hadn’t. This is a pretty dramatic result – subject to the above confounders, of course. 
Effectiveness of precautions against droplets and contact in prevention of nosocomial transmission of SARS is larger and more prestigious, and looked at a cluster of five hospitals. Staff in these hospitals used a variety of mask types, including jury-rigged paper masks that no serious authority expects to work, surgical masks, and N95 respirators. It found that 7% of paper-mask-wearers got infected, compared to 0% of surgical-mask and respirator wearers. This seems to suggest that surgical masks are pretty good. 
... 
I was able to find one study like this outside of the health care setting. Some people with swine flu travelled on a plane from New York to China, and many fellow passengers got infected. Some researchers looked at whether passengers who wore masks throughout the flight stayed healthier. The answer was very much yes. They were able to track down 9 people who got sick on the flight and 32 who didn’t. 0% of the sick passengers wore masks, compared to 47% of the healthy passengers. Another way to look at that is that 0% of mask-wearers got sick, but 35% of non-wearers did. This was a significant difference, and of obvious applicability to the current question.

4. Do surgical masks prevent ordinary people from getting infected outside the healthcare setting? 
... 
It looks like they’re saying masks work a little, they’re too annoying for it to be worth it for normal people, but they might be worth it for the especially vulnerable. But then why don’t they just say masks work, and let each person decide how much annoyance is worthwhile? I’m not sure. But it looks like the author basically ends up in favor of community use of surgical masks in a pandemic, mostly on the basis of per-protocol analyses of community RCTs.

5. How do surgical masks and respirators compare in hokey lab studies? 
Our source here is Smith et al 2016, Effectiveness Of N95 Respirators Versus Surgical Masks In Protecting Health Care Workers From Acute Respiratory Infection: A Systematic Review And Meta-Analysis. They review some of the same studies we looked at earlier, but then investigate 23 “surrogate exposure studies”, ie throwing virus-shaped particles at different masks in a lab and seeing if they got through. You can find the results of each in their appendix. Typically, about 1 – 5% of particles make it through the respirator, and 10 – 50% make it through the surgical mask. ... 
... 
I think in general the fewer virus particles get through your mask, the better, so I think this endorses surgical masks as better than nothing, since their failure rate was less than 100%. 
Booth et al, 2013 examines surgical masks themselves more closely. They hook a surgical mask up to “a breathing simulator” and then squirt real influenza virus at it, finding that:
... 
The paper doesn’t discuss how particle number maps to infection risk. Does letting a single influenza virus through mean you will get infected? If so, any reduction short of 100% is useless. I have a vague sense that this isn’t true; your immune system can fight off most viruses, and the fewer you get, the better the chance it will win. Also, even respirators don’t claim to reduce particle load by more than 99% or so, and those work, so it can’t be that literally a single virus will get you. Overall I think modest reductions in particle number are still pretty good, but I don’t have a study that proves it.

6. Is it true that the public won’t be able to use N95 respirators correctly? 
Yes. 
I remember my respirator training, the last time I worked in a hospital. They gave the standard two minute explanation, made you put the respirator on, and then made you go underneath a hood where they squirted some aerosolized sugar solution. If you could smell the sugar, your respirator was leaky and you failed. I tried so hard and I failed so many times. It was embarrassing and I hated it. 
... 
Bunyan et al, 2013, Respiratory And Facial Protection: A Critical Review Of Recent Literature, discusses this in more depth. They review some of the same studies we reviewed earlier, showing no benefit of N95 respirators over surgical masks for health care workers in most situations. This doesn’t make much theoretical sense – the respirators should win hands down. 
The most likely explanation is: doctors aren’t much better at using respirators than anyone else. In a California study of tuberculosis precautions, 65% of health care workers used their respirators incorrectly. That’s little better than the general public, who have a 76% failure rate.


10 comments:

  1. For more than 15 years I have visited the PowerLine Blog nearly daily. They have a long track record a dropped pass happens.

    Again thanks for your work.

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    1. I visit it every day. Not just nearly. I don't always agree, but that's OK. As I said, this "dismayed" me.

      Tx.

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    2. You give the PowerLine boys more credit than I do. John Hinderaker (who wrote the piece that dismayed you) is the best of the lot. I have found Paul Mirengoff to be a tiresome #NeverTrumper. Scott Johnson can be pretty good. I don’t consider lawyers to be experts.

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    3. PS. I still read John. And sometimes Scott.

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    4. I don't always agree with Paul, but, I would not describe him as a NeverTrumper. He has openly implied that he wants the President to be reelected. I'd say he supports the President 55 to 60% of the time. I'd also say as time goes on, that his needle has moved slightly in favor of Donald.

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    5. I read Paul, don't always agree, but he's a smart lawyer and I like to bounce my views off those of intelligent people. However, I do find what I regard as his 'snark' toward Trump rather tiresome at times.

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  2. The Powerline article provides a thoughtful perspective on the proportion of the coronavirus epidemic.

    You seem to be too outraged about such a perspective.

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    1. I read the UW report yesterday. I found it interesting but, like Hinderaker, I thought that the authors were not transparent about their underlying assumptions. To that extent, Hinderaker has a valid point regarding the various 'models.' And the 'modeling' process generally.

      However, I think he veers off course early on when he refers to the 'hysteria' surrounding the pandemic. That loaded term also rests on assumptions, and I think Trump is in a far better position to judge the adequacy or inadequacy of the assumptions behind his actions. Shouting 'hysteria' in a country under threat of a potentially deadly pandemic isn't terribly helpful and--given what we have known since 2003 about the potential of SARS as a killer--isn't a terribly balanced judgment. Based on what was already known about SARS-like coronaviruses, I continue to maintain that Trump had no option but to take the actions he has taken.

      Hinderaker compounds that initial lack of balance by comparing very dissimilar diseases--dissimilar in their etiology, potential for treatment, dissimilar in all the respects I listed. He makes it worse by comparing a disease to causes of death that have nothing to do with disease--at least not in their operation: suicide and accident. That's not a thoughtful perspective--at all.

      I'm not here to tell you how many people will die in this pandemic. I'm only here to defend Trump's actions, which I regard as justified, and to point out when models or perspectives that are advanced for public discussion are conceptually flawed. Hinderaker's perspective is conceptually flawed in fundamental ways, and therefore not helpful.

      BTW, I wasn't aware that I expressed 'outrage.' I did express 'dismay' and I did characterize the article as 'rather silly.'

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    2. He is comparing the numerical proportions of the diseases -- not the etiology, etc.

      He is pointing out that more than 83,000 people die of diabetes every year. Of course, diabetes is different from coronavirus.

      People thinking about the coronavirus epidemic should recognize how its deaths fit into proportion with other deaths.

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    3. "He is comparing the numerical proportions of the diseases -- not the etiology, etc."

      I think I knew that, Mike. In fact I pointed that out very specifically. It's the very reason why Hinderaker's comparison is invalid and silly. It's impossible to think about Covid19 deaths in proportion to other deaths without taking those factors into consideration. By failing to do so, Hinderaker ends up with a rather silly blog post.

      I go on in the rest of my blog to consider the connection between the effect of social distancing on BOTH influenza and Covid19--as well as the fact that we're discovering that there may be common treatments. That's a useful perspective, because it addresses one of the most common criticisms of the reaction to Covid19--that the reaction seems disproportionate when compared to a rather similar and recurring viral pandemic. I suggest that there may be validity in that criticism, but that the validity leads us in a different direction. Rather than ignoring the new viral pandemic, I suggest, we should recognize that there has always been more that could have been done about the previously existing flu pandemic. Thanks for recognizing that.

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