Showing posts with label epidemiology. Show all posts
Showing posts with label epidemiology. Show all posts

Sunday, August 30, 2020

Why Don’t the Dutch Wear COVID Masks?


Vlog

This post is available as a vlog. Why? Just trying to serve you better! Perhaps you just got back from the eye doctor and your pupils are dilated, so it’s really hard to read the screen text. In that case, just roll the video, kick back, gaze at the blurry talking head—or not!—and let the audio monologue wash over you, leaving you deeply edified, catatonic, or both! (For the regular text version just scroll down. Obviously.)


Introduction

I was surprised to learn recently that the Dutch government not only doesn’t require face masks to stop the spread of the coronavirus, but formally opposes masks, telling people that they don’t help and might even hurt. I decided to delve into this and learn more about it—not just by reading up on the subject, but by sending a survey to both Dutch and American citizens, to compare the results. In the process I have, surprisingly enough, hit upon a novel way forward that could really help.

What the Dutch government says about masks

According to this article in the British Daily Mail, Coen Berends,  spokesman for the Dutch National Institute for Public Health and the Environment, stated, “Face masks in public places are not necessary, based on all the current evidence. There is no benefit and there may even be negative impact.”

(Based on all the current evidence? Like, every study worldwide? Really? This post isn’t primarily focused on the effectiveness of masks, but for more on this question see the appendix.)

The article goes on to say, “Christian Hoebe, a professor of infectious diseases in Maastricht … [and] head of infectious disease control in Zuid-Limburg, the region hit hardest when the pandemic struck Holland, pointed to a Norwegian study showing 200,000 people must wear surgical masks for one week to stop a single Covid-19 case.”

Okay, I’m just going to stop right here and cry bullshit on the Norwegian study. It fails the sanity test. Meanwhile, basing Dutch policy on a Norwegian study seems a bit flimsy now, considering that the government of Norway, two weeks ago, revised their own position on masks. According to this article, “the ministry recommends face masks as an extra precaution when it is difficult to maintain a ‘social distance’ of one meter or more on public transportation.” Granted, this is still a far cry from a nationwide mandate, but if the Norwegian government really believed 200,000 people must mask up for a week to stop one case, they wouldn’t have made this recommendation. The researchers who came up with that 200K figure are, in strict epidemiological terms, whacked out on coke and smack.  (I note that Holland already mandates masks on public transit.)

Setting aside the Norwegian article, let’s dig in to the Dutch government’s assertion that there’s no benefit and there could be possible negative impact. According to this Reuters article, “RIVM chief Jaap van Dissel … argued wearing masks incorrectly, together with worse adherence to social distancing rules, could increase the risk of transmitting the disease. ‘So we think that if you’re going to use masks (in a public setting) ... then you must give good training for it,’ he said.”

Okay, so here’s a novel idea: how about simply providing that training? How hard could it be? After all, the Dutch have done a great job teaching contraception. As described here, they have the lowest abortion rate in Europe. I think van Dissel’s lack of faith here seems unreasonably defeatist.

And how about empirically investigating the relationship between mask wearing and social distancing? Turns out, a study has done just this. As detailed here, “A group of researchers observed people walking the streets of the Dutch capital and found that wearing masks did not give anyone a false sense of security … As part of the research, Lindegaard analysed video footage from June 1 of a shopping street in Amsterdam that was not particularly overcrowded. The footage showed that people wearing a mask violated the 1,5 metre distance rule just as frequently as people not wearing masks. Her research also found that 80 percent of those wearing masks wore them correctly.”

(Note that this fellow here is French, not Dutch.)


How do the Dutch people feel about masks?

Masks are frankly a pain in the ass, so it’s not surprising that crack investigative journalism turned up some decidedly anti-mask attitudes. The Daily Mail article reported that the Dutch government’s policy has brought about “the delight of all the citizens I spoke with in Amsterdam. ‘I hate wearing them,’ said Aicha Meziati, 29, in the hip fashion store Das Werk Haus. ‘They are horrible. People look like they have nappies on their faces.’”

(Since most of my audience is American, I’ll point out here that a) a “nappy” is a diaper, and b) both paper and cloth masks can resemble diapers. Probably few Americans have ever seen a cloth diaper, but trust me, they look a whole lot like white cloth face masks, like the ones my employer mailed me.)

Notwithstanding the retail employee’s pithy statement (which, by the way, showcases a rather naïve attitude toward the seriousness of this pandemic), the Mail goes on to say that “two recent polls claim a majority [of Dutch citizens] back use of face masks for indoor public spaces.” The Mail doesn’t cite either poll, but I found this article that states, “In a weekly poll conducted by political researcher Maurice de Hond, 55 percent of the [Dutch] people surveyed revealed they think face masks should be made compulsory in order to help battle a second wave of the coronavirus.”

I wouldn’t put too much stock in any one survey, but I’ll bet there are more Dutch citizens who support a mask mandate in the abstract than there are Dutch citizens who actually wear masks. It’s human nature to go with the flow and not be that odd person taking a precaution that nobody else is. If I somehow found myself in Holland right now, I’d be more conflicted about going outside with a mask on than I am in the U.S., because I wouldn’t want anyone construing my behavior as a silent judgment against theirs.

Now let’s get to my survey results, and the thoughtful comments from my Dutch respondents, whose direct personal experience can nicely supplement the stuff I’ve read online.

The survey responses

I’ll have to start out by saying my survey was not very broad … only three Dutch citizens responded. I’m only one guy and the research budget for albertnet is zero. Still, I hope you’ll agree three bits of anecdotal evidence are better than nothing. (If you don’t, click here.)

Of the three Dutch respondents to my poll, none wears a mask. Two of these respondents, asked why not, chose the answer, “I’m not sure the Dutch government is right about masks but I don’t wear one because if I did, I would stand out.”

The third respondent chose the answer “I agree with the Dutch government that masks aren’t helpful so I don’t wear one,” with this added comment: “While I answered no, I do think masks would be useful if they: - Are quality masks - Are switched regularly (never worn consecutively) - Are actually worn over the mouth and nose. However as is the case, the quality masks that make a difference are reserved for healthcare workers. This leaves the rest to wear masks that don’t really work.” So this is a bit different than saying masks couldn’t help.

Asked if the Dutch government should require masks, one Dutch respondent answered yes, “Because it makes it more visible that Covid is present. Makes people more aware that they have to keep distance.” The two others could  not decide. One of these two says, “I think it’ll cause too much protest” and the other says “if it was made easier (or cheaper) to get quality masks, and everyone does it correctly, I would make it mandatory.”

Holland vs. U.S.

I’m not going to compare overall Covid rates between the US and Holland, nor compare the efficacy of our governments, other than to say when I mentioned the Dutch government’s position to my daughter, she replied, “I love that we’re not the only idiots!”

What I want to explore is how consensus in a community can be a very comforting thing, especially during such difficult times. I mentioned already that in the absence of a mandate the Dutch people will tend to behave the same—that is, not wear masks.

Happily, I don’t have to worry about offending anyone in my community when I wear a mask. Of the 19 American respondents (all of whom are on my bike club, and are thus local), 17 believe masks help, and two chose “I really don’t know.” Regarding a nationwide mask mandate, 15 support it, three can’t decide, and only one opposes it. My American respondents’ comments tended to be about wide open spaces and the need to address regional differences but with consistent, national thresholds applied.

Suffice to say we’re all on the same page in my neighborhood. Contrast this to other parts of the U.S. where you can be hassled for wearing a mask, or for not wearing one, depending on your neighborhood and/or whom you happen to encounter. At least in California we have a statewide mandate, so wearing a mask doesn’t make much of a statement (other than “I don’t want to get in trouble with the law”). Nobody can differentiate between the “us” who only wear a mask because they’re required to, and the “them” who really believe masks are helpful (or vice-versa if you’re on the other side of the fence). So you have widespread adoption of a behavior that reduces the spread of the coronavirus, without all the social friction. I would love to see this be adopted nationwide, and I think this would help in the Netherlands as well. Anywhere, really.

Can the Dutch government change their tune?

Initially, the CDC in the U.S., along with the World Health Organization, discouraged the use of masks, but as more data have become available, both agencies have changed their position. Is it realistic to assume the Netherlands may eventually fall in line?

Well, it could be tricky politically. This Dutch News article points out, “Last week microbiologist and epidemiologist Amrish Baidjoe wrote an open letter to the cabinet urging ministers to back the wearing of masks indoors. He accused [RIVM Chief] Van Dissel and prime minister Mark Rutte of being worried about the damage to their image if they changed their mind. ‘They have been saying masks do not work for too long, and that makes it difficult to change,’ he said. ‘It is part of a trend of being far too definitive in communication about things which are not so certain.’”

It could be that this accusation is unfair, and/or the supposed fear of political embarrassment is unfounded. My (albeit tiny) survey suggests this. I asked how my Dutch respondents would feel if the government changed their minds and started requiring masks in public. Two chose the reply “I would be relieved because I think we’d be safer with a mask requirement” and the third chose “None of the above” and commented, “I would be annoyed because masks are annoying. However, if they made it mandatory they probably did it based on scientific research. This would make me relieved because that means there is a safer way to go out in public. If they did it without any reason I would pick option 3 [less respect for Dutch government].” Fair enough.

I asked specifically if the Dutch respondents would lose respect for their government simply for abandoning their initial position (i.e., for being wishy-washy). Two responded that “This wouldn’t affect my opinion of the Dutch government” and one added, “I like that the government bases the decisions on science and follows what the RIVM says about it. I realize new studies can show new things and I trust the RIVM in evaluating what studies are trustable.” The third respondent chose the response, “I would have more respect for Dutch government because they can admit when they’re wrong.”

Is there a quick fix?

Unfortunately, to get the Dutch government to change their position would require that new evidence be put in front of them, or that they take another look at existing studies … both of which would take precious time, while the rate of infection is climbing. Is there another, faster way forward?

There is! We don’t actually need to persuade the Dutch government that masks prevent airborne transmission of the coronavirus … we just need to give them other reasons why masks should be worn. I have come up with three very compelling ones.

First, if aligned with a powerful campaign of public service announcements, a mask mandate could increase social distancing behaviors. The key is to focus on a particular side effect of prolonged mask wearing: maskne. This is the problem of mask-induced acne, and as detailed here, it’s a real enough problem that “the Covid-19 task force of the American Academy of Dermatology (A.A.D.) felt compelled to release advice on the subject.” So, if a nation is required to wear masks in public, and masks cause maskne, what is the natural human reaction? To stay home! And that’s exactly what needs to happen. Too many people are going out there on stupid, needless errands just because they’re bored of being housebound. Well, boo hoo hoo … people are dying! If you hired a bold filmmaker like Lars von Trier to create an absolutely grotesque and graphic PSA video of mask-induced acne, with a tagline like “Maskne is not worth it … please just stay home,” the good people of Holland might do just that.

Next, we need to point out to the Dutch government a simple fact that so often goes unappreciated: masks can be very, very sexy. Just look at how beautiful and mysterious this woman looks:


The fact is, even if not all people are beautiful, almost everybody has pretty eyes. Alas, so often the effect of nice eyes is ruined by nose hair, unkempt beards, cigarette-stained teeth, or a weak chin. A mask easily hides these shortcomings. The trick is to furnish the Dutch people with elegant masks that actually enhance their appearance. It would be a pity if somebody spoiled the effect with an ill-advised design like one of these:



Finally, we need to impress upon the Dutch government that the pandemic is not the only global crisis right now: there’s also the economic turmoil that Covid-19 has wrought. It’s time to get businesses back on their feet, and masks can be a big part of that. How? One word: advertising. These pro cycling teams have the right idea:




If the Dutch government suddenly mandated the wearing of masks when in public, for these reasons alone and irrespective of masks’ efficacy in reducing airborne spread of the coronavirus, they could slow the spread of COVID-19 and eventually look like heroes to the Dutch people.

Appendix – Should we believe that masks help?

This study “provides evidence from a natural experiment on the effects of state government mandates for face mask use in public issued by fifteen states plus Washington, D.C., between April 8 and May 15, 2020 … Mandating face mask use in public is associated with a decline in the daily COVID-19 growth rate by 0.9, 1.1, 1.4, 1.7, and 2.0 percentage points in 1–5, 6–10, 11–15, 16–20, and 21 or more days after state face mask orders were signed, respectively. Estimates suggest that as a result of the implementation of these mandates, more than 200,000 COVID-19 cases were averted by May 22, 2020.”

Meanwhile, this publication declares, “In countries with cultural norms or government policies supporting public mask-wearing, per-capita coronavirus mortality increased on average by just 8.0% each week, as compared with 54% each week in remaining countries.”

The University of California at San Francisco (UCSF) medical school is very highly respected, and I have all too much firsthand experience with their hospitals and medical centers, all of it positive. They published this very compelling article explaining why masks are helpful, and how the CDC and WHO came to reverse their earlier positions. Among other evidence, the article cites case studies from UC San Francisco epidemiologist George Rutherford, MD and infectious disease specialist Peter Chin-Hong, MD: “In one case, a man flew from China to Toronto and subsequently tested positive for COVID-19. He had a dry cough and wore a mask on the flight, and all 25 people closest to him on the flight tested negative for COVID-19. In another case, in late May, two hair stylists in Missouri had close contact with 140 clients while sick with COVID-19. Everyone wore a mask and none of the clients tested positive.”

Of course, you don’t need to believe any of this to support a worldwide mask mandate. The Netherlands should impose one for the indisputable social value of masks: their sex appeal, the advertising space, and the maskne-driven increase in improved shelter-in-place behaviors.

More reading on the pandemic 
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Sunday, May 24, 2020

When Will the COVID-19 Pandemic End?


Introduction

Right off the bat, I’ll say that this post won’t answer the question posed in the title—it will merely examine one methodology for addressing the question. And, obviously, I’m not an epidemiologist or any kind of expert. That said, I’ve found a way to look at the pandemic that has given me some measure of relative peace vs. just freaking out.

By the way, for once I’m not going to try to make this a funny post. If anybody finds humor here it’ll be months or years from now when the puny perspective and inevitable inaccuracy of my model and approach will be glaringly, laughably obvious in retrospect.


Who needs a model?

For me, one of the most stressful aspects about this situation is that not only do we not know how it’ll end, but we have no idea when. At least with a final exam coming up or a term paper due, we know when our stress will be over. For better or for worse, that final will be done at 4:00 p.m. on Wednesday, May 27. Whatever kind of shape that essay will be in on Friday, it’ll have been turned in and that’s that. As badly as we’re suffering on a long climb during a bike race, we know there is a summit, and at what mileage or altitude we’ll reach it, even if we haven’t raced the course before. With this pandemic, though, nobody knows where the finish line is. Could this go on for years? It could … the world has seen that before. Not knowing adds to the emotional strain.

Isn’t it enough to follow the news? Well, that hasn’t really helped me. Not only is too much news just depressing, but there’s just not enough consensus to be useful. The media points out what is salient, and discord usually is. Meanwhile, much of what we read is speculation about what could happen (the “news” being that somebody said it), without much effort to say which scenario is the most likely. News is divergent, not convergent.

My solution is to create a mathematical model to forecast the arc of this pandemic. Though this model is extremely crude, it has the ability to improve over time, and at least it’s based on numbers. It gives me some peace, so I figure it might help you, too … but only if we are in basic agreement about what will end the pandemic.

The end of COVID-19: two scenarios

If we could plumb the collective consciousness of the people, across the entire spectrum of humanity, we’d come across all kinds of notions as to how this situation will be resolved. There would be the vague hope that somehow it’d just end, like it would just go away, the way mad cow, SARS, and Ebola seemed to. We’d also find various flavors of denial that this virus actually exists at all, and/or that it’s actually worse than the flu. But if we’re going to try to be reasonable about this, I think we should limit the possible resolutions to two scenarios: 1) enough people are infected that virus can’t find any new hosts (i.e., we reach herd immunity), or 2) a vaccine is developed. Now, if you disagree that the resolution will probably take one of these two forms, that’s totally fine … but you might as well stop reading here. I don’t want to waste your time.

I think it’s possible that a vaccine will come to the rescue. I don’t think anybody is ruling this out, and obviously loads of people are working on that vaccine, and this work simply has to happen because future waves of this coronavirus, or the next one, are probably inevitable. All this being said, I have two problems with hanging my short-term sanity on the prospect of a vaccine.

First, the existence of an effective vaccine doesn’t equate to a swift and efficient means of rolling it out in this country. Vaccinating people isn’t as easy as rolling out a new software version to phones or computers. America is really good at making money, but not very good at making good healthcare available to our entire population. If our performance thus far during this pandemic is any indicator, the time between somebody in this world developing a good vaccine and Americans actually getting it could be very long.

Second, creating a vaccine takes as long as it takes … we can’t just slap a launch date on it. Any time lots of people collaborate on something complicated, delays are inevitable. I have worked in tech for almost 25 years and have seen more deadlines missed than achieved. The only engineering deadline that had any teeth was Y2K, and the entire industry breathed a huge sigh of relief that we fixed our networks in time for that. But Y2K was a lot simpler than a vaccine … it was just cleaning up sloppy software.

The conventional wisdom around the rough timeframe for a vaccine, to the barebones extent I’ve investigated it, is at least a year. WebMD, for example, says it’s 12-18 months out. I suspect herd immunity will come before then, because that’s what my model predicts. If it seems reasonable to you that herd immunity could be achieved before a vaccine, read on.

My pandemic prediction model

I’ve hunted around a bit to see what the generally accepted rate of infection is for achieving herd immunity—that is, the point when the virus can no longer spread due to lack of available hosts. The number I’ve settled on is 70%. (It’s not that important that you agree with this figure because it’s easy enough, with the spreadsheet, to swap it out for something else, which I may do if suddenly all the experts are saying we need 75%, or only 65%.) Multiplying 70% by US population, I come up with 230 million who need to be infected before the virus stops spreading. If we reach that number before 12-18 months, that’ll be the end of COVID-19 in this country (assuming we have some combination of worldwide herd immunity and international travel restrictions).

To figure out to long it’ll take to reach this level, we have to calculate what the current rate of infection is. I’ve been watching the daily stats on Infection 2020, a website my daughter alerted me to. It compiles data from a number of sources: the website cites “CDC, WHO, The New York Times, JHU, Corona Data Scraper, and official state and county health agencies.” Every day, it posts the rate of increase vs. the day before.

Is this website perfect? Of course not. One of the most maddening aspects of this situation is that we can only really guess about how many people have actually been infected with this coronavirus, given the abysmal state of our testing capability so far. I have no doubt that hundreds of thousands of infections, perhaps a majority, have not been documented. But I think it’s still worth using this data, because it will get more accurate over time, and I think you have to start somewhere … otherwise you can’t model anything and your take on the situation will get yanked in too many directions.

When I created my model a little over a week ago, I’d been watching these stats for a couple of months, during which period I’d seen the rate of growth fluctuate between 1 and 4%. It was mostly around 4% at first, and then gradually dropped. Lately it’s been 2% or 1%. The problem is, the growth rate figure is not very precise—it’s only one significant digit—so it flip-flops between 1% and 2% based on the time of day when I check. That’s all the difference in the world.

To get past this imprecision, I created a spreadsheet that models three different growth rates: 2%, 1.5%, and 1%. I started with the actual values as reported by the website on May 16, and copied the formula [previous value * 1.02] down far enough to where the total cases reaches (roughly) 230 million. Here is what the 2% growth forecast looks like (with a ton of rows omitted so the snapshot is manageable):


What the above shows is that if the infection rate proceeds at 2% day-over-day growth, we’ll reach the necessary 70% infection rate by the end of January, next year. Now, of course the infection rate won’t be constant like that … it is bound to go up as we relax the shelter-in-place rules. Or maybe it won’t … many seem to think it’ll flatten out, and for the last couple of months it has. But at least this is a starting point, and it’s easy enough to tweak the model and the situation changes.

Here is the next tab of my spreadsheet, based on a forecast of 1% day-over-day growth in the infection rate:


It has this pandemic lasting until October 5 of 2021 unless a vaccine comes out before then. Is that realistic? Perhaps not, but no matter: I also did a 1.5% model:


The 1.5% model has us reaching herd immunity toward the end of next April.

Now, all three models project a 6% fatality rate, because that number hasn’t changed in months. You may be wondering if I truly believe this pandemic will kill almost 14 million Americans. No, of course I don’t. Keeping in mind that most of the cases we know about are people showing bad enough symptoms to get tested, they’re probably the more vulnerable populations. As more and more people get the virus, we’ll be into the more mainstream cohort: younger and healthier. Meanwhile, as mentioned before, surely countless people have had this virus, or have it now, without being tested. The fatality rate is deaths divided by known cases; as the number of known cases grows, outpacing the deaths, the known fatality rate will fall dramatically.

So which of these three models is most accurate at the moment? That’s easy to measure simply by filling in the actual numbers as we go. I added formulas to subtract the actual values from the forecasted values, day by day, across each model, so we can see which one proves most accurate. Here’s what the 2% model shows so far:


Clearly, the forecast is pretty far off and getting worse. In other words, 2% is too aggressive an assumption, thus January 26 is too early a date to expect herd immunity to be reached.

Let’s look, then, at the 1% model:


It’s also pretty far off, though a bit better than the 2% model. (Not long ago, it was farther off than the 2% model, so we can tell the rate of infection is declining.) The numbers are in red because they’re negative, meaning the model is too optimistic and is predicting fewer cases and deaths than we’re seeing. But they’re smaller numbers, indicating greater accuracy.

Here is the 1.5% forecast:


It’s a fair bit closer than either of the other two models, which isn’t surprising since the reported rate has been bouncing between 1% and 2%  due to the rounding the website does. For that to happen, the actual rate would have to be somewhere in the middle.

Does this mean I should discard the 1% and 2% models? No, because the rate could swing in either direction from here. Over the next weeks and months as events unfold, I’ll probably add more tabs modeling other rates of infection if they do a better job. This gives us a way to contextualize the numbers we see each day. At some point if things are departing sufficiently from what we’ve observed since May 16, I might start over, basing the forecast on the number of cases as of that date (i.e., instead of the 1.48 million we had on May 16).

Over time, the model will change constantly, reflecting more and more new data and the effect that government policies and human behavior have on the spread of infection. If it turns out that fear, and not regulation, is driving social distancing behaviors, the rate might not go up by much. On the other hand, if people revolt and businesses start opening up again willy-nilly, the rate could skyrocket. These things cannot be predicted but their effect can be fed into the forecast.

So what I’ve created here is a model that says today, based on what is now known and what’s going on at this moment, I have a tentative herd immunity forecast date. As of May 24, I have at least some basis to believe that this pandemic will be over by April 20 of next year, after which the long, slow return to normal can begin. Notwithstanding the crudeness of my model, it gives me comfort just to have this projected date, vs. speculating endlessly about what could happen.

If this end date idea appeals to you too, I’m happy to share my spreadsheet … just drop me an email. Or, if you’re a lot better at such modeling than I am, I’d love to hear your comments and/or see your forecast. Or, if I have missed some all-important consideration and you’re able to shoot holes in my entire framework here, such that I discard it completely, I’d rather do that than stumble forward ignorantly, deceiving myself. (Will this post have been a totally wasted effort in that case? Mostly, yeah … but it’ll also be, arguably, an interesting historical testament to the kind of agonized cogitation this pandemic has brought about.)

More reading on the pandemic
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