The Science of Masks 7: Government and NGO Reports
WHO said what?
Welcome back to my insane posting about what was until recently a pretty obscure field of medical research, interspersed with occasional commentary on episodes of a 1990s sitcom that no one but me remembers.
It may come as a shock, but before this subject became politicized the World Health Organization published a summary of the research on non-pharmaceutical interventions. You know, in case we have a pandemic or something.
We’re (I’m) also up to Dharma & Greg Episode 17: “The Official Dharma & Greg Episode of the 1998 Winter Olympics” in which the writers have a bit of fun with the over-the-top licensing efforts of the International Olympic Committee in the 1990s. “These snacks were brought to you in a paper bag, the official food transport device of the Winter Olympics.”
This will be short but the WHO are not the only ones who have weighed in on this subject, so jump in your bobsled and let’s go for gold.
WHO publishes some research (in 2019)
In 2019 the World Health Organization published a detailed (over 200 pages including the annex, and hundreds of references) review1 of 18 different non pharmaceutical interventions (NPIs) and the evidence for the effectiveness of those interventions in mitigating an influenza epidemic. Of course one of the interventions being investigated was masks. Once again, this was in 2019. Did I mention this was published in 2019?
For a few of the different NPIs discussed the authors did not identify any scientific studies. For most of the others, the quality of the available evidence was rated low or very low (or non-existent). Only two NPI measures had evidence they rated as moderately good, and those were hand hygiene and face masks. For both, the balance of the evidence was a lack of effectiveness in reducing influenza transmission.
The authors looked at the results of 10 randomized controlled trials using either masks alone or masks plus hand hygiene, and they summarized their findings succinctly.
Ten RCTs were included in the meta-analysis, and there was no evidence that face masks are effective in reducing transmission of laboratory-confirmed influenza.
By the way, do you remember when Anthony “Mengele” Fauci told us not to wear masks, and just wash our hands? It’s an interesting coincidence that those are the only two items the WHO report said had at least some evidence. We’re taking bets over here on “stupid” or “evil” and the latter of those two might be winning.
Their final recommendation on face masks was to conditionally recommend them despite the lack of evidence masks will do any good, since a benefit is at least plausible. (So not totally impossible! Not exactly a strong endorsement but apparently enough justification for some people to want to muzzle your five year old. Do these people just hate children?)
Face masks worn by asymptomatic people are conditionally recommended in severe epidemics or pandemics, to reduce transmission in the community. Disposable, surgical masks are recommended to be worn at all times by symptomatic individuals when in contact with other individuals. Although there is no evidence that this is effective in reducing transmission, there is mechanistic plausibility for the potential effectiveness of this measure.
So there’s no evidence that masks will reduce transmission of viruses - it’s right there in black and white. But they “conditionally” recommend them anyway because, hey, why not? It’s not like this will blow up into some crazy dystopian Hunger Games type thing, right?
The report itself is 85 pages with 241 references, and is accompanied by an annex that’s 119 pages with 265 references. The authors are somewhat upbeat about hand hygiene and masks, generally recommending that we give them a try while simultaneously admitting that randomized controlled trials have not actually shown any benefits.
On page 99 of the Annex, in a short section titled Summary of Evidence, there is a blunt summary of the evidence in a little table listing each NPI, the quality of the available evidence, and the results from that evidence.
For face masks, the quality of the evidence is listed as moderate, meaning there are at least some randomized controlled trials (RCTs) to reference, but their summary of the RCTs was that face masks are not effective in reducing the transmission of influenza.
As pointed out several times so far, they found mechanistic evidence for potential effectiveness of masks, but no real world evidence they have actually worked. Which is the same as my summary at the end of Part 6.
The authors did not look at potential negative effects of masks.
[Meanwhile Dharma and Greg are being typical Dharma & Greg:
D: “Hi honey. Where you been?”
G: “Me and the guys flew to Tahoe and went down the mountain backwards in a canoe.”
D: “Good for you.”
G: “What about you?”
D: “We put your mom in a black wig and took her down to the navy base to party with a bunch of drunk sailors.”
G: “Good for her.”]
Report from the Institute of Medicine on influenza pandemics
In 2008 the Board on Health Sciences Policy of the Institute of Medicine wrote Preparing for an Influenza Pandemic: Personal Protective Equipment for Healthcare Workers2. Published by the National Academy of Sciences, this work was also supported by the CDC.
This study was requested by the National Institute for Occupational Safety and Health of the Centers for Disease Control and Prevention and was supported by Contract No. 200-2005-10881 (Task Order #6), between the National Academy of Sciences and the Centers for Disease Control and Prevention.
In chapter 1 (page 34) they explain the difference between medical masks and respirators.
One of the challenges for the healthcare field is to clearly understand the differences among respirators and medical masks as well as their appropriate uses. Medical masks (the term is used in this report to encompass surgical masks and procedure masks) are loose-fitting coverings of the nose and mouth designed to protect the patient from the cough or exhaled secretions of the physician, nurse, or other healthcare worker.
And they point out that medical masks are not designed to protect the wearer from airborne hazards, which is important to note since so many people are currently wearing them for that purpose.
Medical masks are not designed or certified to protect the wearer from exposure to airborne hazards. They may offer some limited, as yet largely undefined, protection as a barrier to splashes and large droplets. However, because of the loose-fitting design of medical masks and their lack of protective engineering, medical masks are not considered PPE.
I’ll bet you didn’t know that medical masks are not considered PPE by the Institute of Medicine. They tell us the purpose of medical masks:
To protect the patient or others from the wearer’s expired respiratory droplets
And respirators:
Designed to reduce the wearer’s inhalation exposure to hazardous airborne particles
Medical masks were not designed to keep people from getting infected, and multiple randomized controlled trials have failed to show that they will. Cloth masks are not designed for anything (except maybe fashion, and profit), and in addition to not stopping infection might even make things worse. At best, these masks will stop some droplets from being expelled by the wearer, although these droplets would only have traveled a few feet anyway.
As described in the Cochrane review in the previous post, there is no evidence surgical masks prevent the wearer from transmitting an infection. And per the National Academy of Science report, medical masks are also not designed to protect the wearer from infection. Surgeons wear surgical masks anyway (and have their own reasons for doing so), but there is no evidence those masks are anything besides useless for the general public.
Summary for the intern at the CDC who took Milton’s red stapler and now he’s going to pay
The World Health Organization and the Institute of Medicine both came to the same conclusion as the authors of the literature reviews, which is consistent with what we saw when we read the studies ourselves - masks don’t help.
Do you see a pattern here? A bunch of randomized controlled trials failed to show masks prevent transmission, a bunch of people reviewing those trials concluded the same thing, and both government and non-governmental organizations agreed.
Remember this the next time some midwit on the evening news tells you the “scientific consensus” is that we should be wearing masks. Nobody seems to agree with the supposed consensus.
Next post - “Why does the guy fixing my roof in the middle of July not want to breathe through several layers of fabric all day?”
And Dharma stalks Jane Seymour.
Non-pharmaceutical public health measures for mitigating the risk and impact of epidemic and pandemic influenza; World Health Organization 2019. ISBN: 978-92-4-151683-9.
https://www.who.int/influenza/publications/public_health_measures/publication/en/
Institute of Medicine 2008. Preparing for an Influenza Pandemic: Personal Protective Equipment for Healthcare Workers. Washington, DC: The National Academies Press. https://doi.org/10.17226/11980.
https://www.nap.edu/download/11980