This graphic appeared in my social media feed today. This graphic was shared by a doctor so it must be true!

Seems very compelling except …

The percentage figures were random values assigned by who knows who. There is no source provided either for the chart or the percentages. What do these percentages even mean? Does 67% mean that in 100 instances, 67 will get Covid-19? That is not supported by data.

The oldest version of this I could find online appeared May 5 – and it does not include any of the percentage figures. Someone added the percentages because – not surprisingly – many people interpret numbers as making a message more authentic. In fact, 58.7% of people think that a message containing numbers is more meaningful … see what I did there? I just made that up!

There is another version of this chart floating around, which Reuters has “fact checked” and says its bogus.

Incredibly – as of June 2020, no one actually knows if wearing a face mask – in addition to social distancing and hand washing – has any impact what so ever on the spread of SARS-CoV-2. Seriously – this is based on conjecture, speculation, an hypothesis, various models and “it feels right”. But there is no actual data answering the question:

Does the use of a home made cloth face mask or improvised face mask worn by members of the public reduce the spread of SARS-CoV-2?

I asked by county public health office, my state’s public health office and the CDC. None have replied. And I asked that question 5 weeks ago.

Source: MARCKCMetro’s tweet – “The stay-at- home orders are now transitioning to recovery plans to allow for the safe reopening of our communities but this does NOT mean a return to ‘normal’. Social distancing, protective masks, and cleaning protocols need to continue. ” – Trendsmap

MARCK is “Mid-America Regional Council is the association of local governments and metropolitan planning organization for the KC region.”, Kansas City, Missouri. Considering their domain of interests, oddly, their Twitter page is mostly about “climate action” and then “Covid-19” topics.

Another version of this graphic includes a different modification of the original incorporating the very sophisticated propaganda method of name-calling:

Remarkably there is not – yet – a single peer reviewed paper showing that home made cloth or improvised face masks stop the spread of SARS-CoV-2.

Yes, there are papers about manufactured surgical masks, and a couple about manufactured cloth masks tested against influenza used by professional health care providers (not the public) … and papers dating back to the 1918 Spanish Flu pandemic that found cloth masks were ineffective. There are recent papers that found cloth face masks had little effectiveness against the flu, and one that found them ineffective for inbound and outbound protection against Covid-19. There are computer model simulations implying masks are great – but a computer model can not prove anything. Only real world data will tell us whether the use of home made cloth face masks protects anyone – and whether we can reject a null hypothesis (which is never stated). We are participating in a mass population wide health experiment – without being a fully informed participant that voluntarily gives consent.

Oddly, in a world that is insistent on controlled trials for everything else, there has been none.

Kind of mind blowing.