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HomeMy WebLinkAbout031623 Rebuttal of false statements re Cochrane review of masking evidence________________________________ ALERT: BE CAUTIOUS This email originated outside the organization. Do not open attachments or click on links if you are not expecting them. ________________________________ Dear Board of Health, Health Officer Berry made multiple false statements at today's Board of Health meeting regarding the gold-standard Cochrane review finding no evidence of mask effectiveness for preventing viral transmission. Shockingly, she asserted it is "no longer ethical" to perform randomized controlled studies on the subject. Berry's statements echoed an evidence-free New York Times opinion column "The Science Is Clear That Masks Work", which is carefully refuted in the article below. Yours truly, Stephen Schumacher Port Townsend, WA === https://www.eugyppius.com/p/zeynep-tufekci-sociologist-and-noxious New York Times columnist insists "The Science is clear that masks work," fails after many words to actually locate any of this mysterious Science eugyppius - Mar 12 Zeynep Tufekci is an academic sociologist, a New York Times columnist ... Her latest piece is an opinion column screaming against all reason and evidence that The Science Is Clear That Masks Work. https://www.nytimes.com/2023/03/10/opinion/masks-work-cochrane-study.html Mostly, Tufekci is very mad about the Cochrane mask review, which found no evidence that masks do anything; and about statements by its lead author, Tom Jefferson, who has explained in various interviews that indeed there is no good evidence that masks do anything. Tufekci is happy to report that - after what we can only presume is extensive harassment by legions of people like herself - Cochrane have agreed to reword part of their summarised findings. When you are facing absolute defeat, small victories become very important. ... Cochrane ... says that the way it summarized the review was unclear and imprecise, and that the way some people interpreted it was wrong. "Many commentators have claimed that a recently updated Cochrane review shows that 'masks don't work,' which is an inaccurate and misleading interpretation," Karla Soares-Weiser, the editor in chief of the Cochrane Library, said in a statement. "The review examined whether interventions to promote mask wearing help to slow the spread of respiratory viruses," Soares-Weiser said, adding, "Given the limitations in the primary evidence, the review is not able to address the question of whether mask wearing itself reduces people's risk of contracting or spreading respiratory viruses." She said that "this wording was open to misinterpretation, for which we apologize," and that Cochrane would revise the summary. Soares-Weiser also said, though, that one of the lead authors of the review [Tom Jefferson] even more seriously misinterpreted its finding on masks by saying in an interview that it proved "there is just no evidence that they make any difference." In fact, Soares-Weiser said, "that statement is not an accurate representation of what the review found." It is, in fact, an accurate representation of what the review found, and it's also functionally identical to Soares-Weiser's much more verbose representation about "limitations in the primary evidence" and those things which "the review is not able to address," but all those syllables give the masktard faithful more places to seek solace. While the review assessed 78 studies, only 10 of those focused on what happens when people wear masks versus when they don't, and a further five looked at how effective different types of masks were at blocking transmission, usually for health care workers. ... Of those 10 studies that looked at masking, the two done since the start of the Covid pandemic both found that masks helped. The calculations the review used to reach a conclusion were dominated by prepandemic studies that were not very informative about how well masks blocked the transmission of respiratory viruses. As I've said before, and as all thinking people should readily affirm, absence of evidence is evidence of absence, particularly given the massive publication bias favouring positive results. Masking has been around in some form for over a century now, and there's been ample opportunity to investigate how well masks work. Particularly since 2020, there's also been near-infinite funding flowing to all matters Covidian. The reason there aren't very many studies on community masking is not that nobody has looked into it, but that nobody can find it does anything. ... [<https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0240287>I]n one study of hajj pilgrims in Mecca, only 24.7 percent of those assigned to wear masks reported using one daily, but not all the time (while 14.3 percent in the no-mask group wore one anyway). The pilgrims then slept together, generally in tents with 50 or 100 people. Not surprisingly, given there was little difference between the two groups, researchers found no difference from mask wearing and declared their results "inconclusive." In <https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0029744>another prepandemic study, college students were asked to wear masks for at least six hours a day while in their dormitories, but they were not obligated to wear them elsewhere. Researchers found no difference in infection rates between those who wore masks and those who did not. The authors noted this might be because "the amount of time masks were worn was not sufficient" ­ obviously, college students also go to classes and socialize where they may not wear masks. Yet despite their inconclusiveness, the data from just these two studies accounted for roughly half of the calculations for evaluating the impact of mask wearing on transmission. The other six prepandemic studies similarly suffered from low masking adherence, limited time wearing them and, often, small sample sizes. I don't know why this is hard: Low quality studies failing to find evidence that masks work still add up to no evidence that masks work. The only prepandemic study reviewed by Cochrane reporting <https://bmcinfectdis.biomedcentral.com/articles/10.1186/1471-2334-12-26>high rates of mask adherence started during the worrying H1N1 season in 2009 in Germany, and found mask wearing reduced spread if started quickly after diagnosis and if a mask was worn consistently (though its sample size, too, was small). For "small" read 218 participants. Note also that these influenza masking studies can be pretty crazy. This one, for example, wanted all participants in the masking arm "to wear [surgical] masks at all times when the index patient and/or any other household member with respiratory symptoms were together in one room with healthy household members," and they further demanded that these masks "be changed regularly during the day." These strict at-home masking regimens have very little to do with Corona-era community mask mandates, and they're also highly likely to discourage social interaction in general, so the effects are hard to disentangle. Despite all of that, the authors still found no significant difference in attack rates between the masked and unmasked arms of their study. This happens all the time in these papers, and the authors generally respond by rooting around in other variables to find a correlation somewhere else. This time, they discovered that, of the 136 participants in the masked arm, 60 who reported masking "no later than 36 hours after symptom onset" of the index patient enjoyed "a borderline significant protective effect." This is super high-level scientific work here. I feel super confident wearing masks at home around your family members prevents influenza. To use randomized trials to study whether masks reduce a virus's spread by keeping infected people from transmitting a pathogen, we need randomized comparisons of large groups, like having people in one city assigned to wear masks and those in another to not wear them. As ethically and logistically difficult as that might seem, there was one study during the pandemic in which masks were distributed, but not mandated, in some Bangladeshi villages and not others before masks were widely used in the country. Mask use increased to 40 percent from 10 percent over a two-month period in the villages where free masks were distributed. Researchers <https://www.nytimes.com/2021/09/26/opinion/do-masks-work-for-covid-prevention.html>found an 11 percent reduction in Covid cases in the villages given surgical masks, with a 35 percent reduction for people over age 60. As we all know, the <https://www.wmbriggs.com/post/37320/>Bangladesh mask study was <https://boriquagato.substack.com/p/bangladesh-mask-study-do-not-believe>garbage. Another pandemic study randomly distributed masks to people in Denmark over a month. About half the participants wore the masks as recommended. Of those assigned to wear masks, 1.8 percent became infected, compared with 2.1 percent in the no-mask group ­ a 14 percent reduction. But researchers could not reach a firm conclusion about whether masks were protective because there were few infections in either group and fewer than half the people assigned masks wore them. The Danish study found no statistically significant effect from masking; whining about adherence is pointless because once again, no evidence is no evidence. Also too, the authors of the Danish study had incredible trouble finding a journal that would publish their results, because they weren't able to show masks prevent infection. Thus we see, as I said above, that <https://www.eugyppius.com/p/most-mask-studies-are-garbage>this entire field is corrupted with massive publication bias in favour of any study at all finding find that masks work, and despite this fact, all anybody can come up with is this weak tea. Scientists routinely use other kinds of data besides randomized reviews, including lab studies, natural experiments, real-life data and observational studies. All these should be taken into account to evaluate masks. Lab studies, many of which were done during the pandemic, show that masks, particularly N95 respirators, can block viral particles. Linsey Marr, an aerosol scientist who has long studied airborne viral transmission, told me even cloth masks that fit well and use appropriate materials can help. Lab studies like this form a great part of the "evidence" that masks are effective at preventing infection. They are also incredibly, boundlessly stupid - the equivalent of showing that wood can float, when called upon to demonstrate the seaworthiness of a sailboat. Real-life data can be complicated by variables that aren't controlled for, but it's worth examining even if studying it isn't conclusive. Japan, which emphasized wearing masks and mitigating airborne transmission, had a remarkably low death rate in 2020 even though it did not have any shutdowns and rarely tested and traced widely outside of clusters. Across the entire Asia-Pacific, regardless of masking practices, Covid case counts and mortality were much lower than in the West. The behaviour of SARS-2 varies massively across regions and seasons, but not across masked and unmasked populations. David Lazer, a political scientist at Northeastern University, calculated that before vaccines were available, U.S. states without mask mandates had 30 percent higher Covid death rates than those with mandates. This Lazer guy is a crank who seems to have churned out various pro-containment Covid surveys throughout the pandemic. I can't find the publication containing this specific 30-percent figure, but I really hope Lazer controlled for things like age, obesity and socioeconomic status, because statewide mask mandates are heavily politicised in the United States, with maskless Republican-governed states being in aggregate substantially older, sicker and poorer than masked Democratic-governed states. Perhaps the best evidence comes from natural experiments, which study how things change after an event or intervention. Researchers at Mass General Brigham, one of Harvard's teaching hospital groups, <https://jamanetwork.com/journals/jama/fullarticle/2768533>found that in early 2020, before mask mandates were introduced, the infection rate among health care workers doubled every 3.6 days and rose to 21.3 percent. After universal masking was required, the rate stopped increasing, and then quickly declined to 11.4 percent. Mass General Brigham instituted universal patient masking from 25 March; allowing for a "lag period to allow for manifestations of symptoms" from 6-10 April 2020, the authors arrive at an "intervention period between 11-30 April 2020." The study is therefore worthless, because case data shows that infections stopped rising across the state of Massachusetts on 17 April. In other words, these geniuses started masking their patients just as Covid achieved a natural peak and then credited their masks with the ensuing seasonal decline. Identical reasoning processes are literally how things like rainmaking rituals arise. In Germany, 401 regions introduced mask mandates at various times over three months in the spring of 2020. By carefully comparing otherwise similar places before and after mask mandates, <https://www.pnas.org/doi/full/10.1073/pnas.2015954117>researchers concluded that "face masks reduce the daily growth rate of reported infections by around 47 percent," with the effect more pronounced in large cities and among older people. This study actually looks at just six German jurisdictions that introduced mask mandates before the federal masking rules. It's got various problems, like the use of "synthetic controls", the failure to take into account test frequency, and so on, but I just want you to notice the insane, utterly impossible effect size. There's no way masks cut infections by 47 percent. The highest quality studies, like the Danish randomised controlled trial, find no statistically significant effect at all, but as you wander outwards to ever worse observational studies, masks look better and better. This is not what the literature looks like when an intervention actually works. [Cochrane editorial board member Michael D.] Brown, who led the Cochrane review's approval process, told me that mask mandates may not be tenable now, but he has a starkly different feeling about their effects in the first year of a pandemic. "Mask mandates, social distancing, the other shutdowns we had in terms of even restaurants and things like that ­ if places like New York City didn't do that, the number of deaths would have been much higher," he told me. "I'm very confident of that statement." So the evidence is relatively straightforward: Consistently wearing a mask, preferably a high-quality, well-fitting one, provides protection against the coronavirus. Although even Tufekci's highly biased and selective review of available studies fails to marshal any evidence showing that masks are effective, she finds somebody on the Cochrane editorial board who will tell her masks saved lives, and that's enough to declare that masks work as far as she's concerned. And the sad thing is, for her readers, that will be enough. work still add up to no evidence that masks work. The only prepandemic study reviewed by Cochrane reporting <https://bmcinfectdis.biomedcentral.com/articles/10.1186/1471-2334-12-26>high rates of mask adherence started during the worrying H1N1 season in 2009 in Germany, and found mask wearing reduced spread if started quickly after diagnosis and if a mask was worn consistently (though its sample size, too, was small). For "small" read 218 participants. Note also that these influenza masking studies can be pretty crazy. This one, for example, wanted all participants in the masking arm "to wear [surgical] masks at all times when the index patient and/or any other household member with respiratory symptoms were together in one room with healthy household members," and they further demanded that these masks "be changed regularly during the day." These strict at-home masking regimens have very little to do with Corona-era community mask mandates, and they're also highly likely to discourage social interaction in general, so the effects are hard to disentangle. Despite all of that, the authors still found no significant difference in attack rates between the masked and unmasked arms of their study. This happens all the time in these papers, and the authors generally respond by rooting around in other variables to find a correlation somewhere else. This time, they discovered that, of the 136 participants in the masked arm, 60 who reported masking "no later than 36 hours after symptom onset" of the index patient enjoyed "a borderline significant protective effect." This is super high-level scientific work here. I feel super confident wearing masks at home around your family members prevents influenza. To use randomized trials to study whether masks reduce a virus's spread by keeping infected people from transmitting a pathogen, we need randomized comparisons of large groups, like having people in one city assigned to wear masks and those in another to not wear them. As ethically and logistically difficult as that might seem, there was one study during the pandemic in which masks were distributed, but not mandated, in some Bangladeshi villages and not others before masks were widely used in the country. Mask use increased to 40 percent from 10 percent over a two-month period in the villages where free masks were distributed. Researchers <https://www.nytimes.com/2021/09/26/opinion/do-masks-work-for-covid-prevention.html>found an 11 percent reduction in Covid cases in the villages given surgical masks, with a 35 percent reduction for people over age 60. As we all know, the <https://www.wmbriggs.com/post/37320/>Bangladesh mask study was <https://boriquagato.substack.com/p/bangladesh-mask-study-do-not-believe>garbage. Another pandemic study randomly distributed masks to people in Denmark over a month. About half the participants wore the masks as recommended. Of those assigned to wear masks, 1.8 percent became infected, compared with 2.1 percent in the no-mask group ­ a 14 percent reduction. But researchers could not reach a firm conclusion about whether masks were protective because there were few infections in either group and fewer than half the people assigned masks wore them. The Danish study found no statistically significant effect from masking; whining about adherence is pointless because once again, no evidence is no evidence. Also too, the authors of the Danish study had incredible trouble finding a journal that would publish their results, because they weren't able to show masks prevent infection. Thus we see, as I said above, that <https://www.eugyppius.com/p/most-mask-studies-are-garbage>this entire field is corrupted with massive publication bias in favour of any study at all finding find that masks work, and despite this fact, all anybody can come up with is this weak tea. Scientists routinely use other kinds of data besides randomized reviews, including lab studies, natural experiments, real-life data and observational studies. All these should be taken into account to evaluate masks. Lab studies, many of which were done during the pandemic, show that masks, particularly N95 respirators, can block viral particles. Linsey Marr, an aerosol scientist who has long studied airborne viral transmission, told me even cloth masks that fit well and use appropriate materials can help. Lab studies like this form a great part of the "evidence" that masks are effective at preventing infection. They are also incredibly, boundlessly stupid - the equivalent of showing that wood can float, when called upon to demonstrate the seaworthiness of a sailboat. Real-life data can be complicated by variables that aren't controlled for, but it's worth examining even if studying it isn't conclusive. Japan, which emphasized wearing masks and mitigating airborne transmission, had a remarkably low death rate in 2020 even though it did not have any shutdowns and rarely tested and traced widely outside of clusters. Across the entire Asia-Pacific, regardless of masking practices, Covid case counts and mortality were much lower than in the West. The behaviour of SARS-2 varies massively across regions and seasons, but not across masked and unmasked populations. David Lazer, a political scientist at Northeastern University, calculated that before vaccines were available, U.S. states without mask mandates had 30 percent higher Covid death rates than those with mandates. This Lazer guy is a crank who seems to have churned out various pro-containment Covid surveys throughout the pandemic. I can't find the publication containing this specific 30-percent figure, but I really hope Lazer controlled for things like age, obesity and socioeconomic status, because statewide mask mandates are heavily politicised in the United States, with maskless Republican-governed states being in aggregate substantially older, sicker and poorer than masked Democratic-governed states. Perhaps the best evidence comes from natural experiments, which study how things change after an event or intervention. Researchers at Mass General Brigham, one of Harvard's teaching hospital groups, <https://jamanetwork.com/journals/jama/fullarticle/2768533>found that in early 2020, before mask mandates were introduced, the infection rate among health care workers doubled every 3.6 days and rose to 21.3 percent. After universal masking was required, the rate stopped increasing, and then quickly declined to 11.4 percent. Mass General Brigham instituted universal patient masking from 25 March; allowing for a "lag period to allow for manifestations of symptoms" from 6-10 April 2020, the authors arrive at an "intervention period between 11-30 April 2020." The study is therefore worthless, because case data shows that infections stopped rising across the state of Massachusetts on 17 April. In other words, these geniuses started masking their patients just as Covid achieved a natural peak and then credited their masks with the ensuing seasonal decline. Identical reasoning processes are literally how things like rainmaking rituals arise. In Germany, 401 regions introduced mask mandates at various times over three months in the spring of 2020. By carefully comparing otherwise similar places before and after mask mandates, <https://www.pnas.org/doi/full/10.1073/pnas.2015954117>researchers concluded that "face masks reduce the daily growth rate of reported infections by around 47 percent," with the effect more pronounced in large cities and among older people. This study actually looks at just six German jurisdictions that introduced mask mandates before the federal masking rules. It's got various problems, like the use of "synthetic controls", the failure to take into account test frequency, and so on, but I just want you to notice the insane, utterly impossible effect size. There's no way masks cut infections by 47 percent. The highest quality studies, like the Danish randomised controlled trial, find no statistically significant effect at all, but as you wander outwards to ever worse observational studies, masks look better and better. This is not what the literature looks like when an intervention actually works. [Cochrane editorial board member Michael D.] Brown, who led the Cochrane review's approval process, told me that mask mandates may not be tenable now, but he has a starkly different feeling about their effects in the first year of a pandemic. "Mask mandates, social distancing, the other shutdowns we had in terms of even restaurants and things like that ­ if places like New York City didn't do that, the number of deaths would have been much higher," he told me. "I'm very confident of that statement." So the evidence is relatively straightforward: Consistently wearing a mask, preferably a high-quality, well-fitting one, provides protection against the coronavirus. Although even Tufekci's highly biased and selective review of available studies fails to marshal any evidence showing that masks are effective, she finds somebody on the Cochrane editorial board who will tell her masks saved lives, and that's enough to declare that masks work as far as she's concerned. And the sad thing is, for her readers, that will be enough.