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A rare Joe twitter thread, on universal masking, covid, and public health: A natural population level science experiment occurring in real-time in Central Europe, that anyone can follow at home. 1/13
One of the arguments for universal masking is that those countries that have successfully tamped down the curve are the countries in East Asia that also have instituted mandatory masking: China, South Korea, and Taiwan, predominantly. https://www.theguardian.com/world/2020/mar/11/mass-testing-alerts-and-big-fines-the-strategies-used-in-asia-to-slow-coronavirus
The reality is this is pretty simplistic as these countries have also instituted a variety of other policies which impact transmission, such as mass testing, mandatory lockdowns, and rigorous contact tracing. So which policy worked? Was it the whole suite of actions? or one? 3/
As this has rolled out across the world, other countries have also emulated the East Asian nation's policies, in particular Germany with mass testing and rigorous contact tracing. Which has lowered but not stopped Germany's Covid transmission. https://gulfnews.com/world/europe/covid-19-mass-testing-empty-icus-germany-scores-early-against-coronavirus-1.1585728025897 4/
But now mandatory masking has rolled out across central Europe. Czechia came first on March 19th https://theguardian.com/world/2020/mar/30/czechs-get-to-work-making-masks-after-government-decree-coronavirus ... inspired by an incredible grassroots campaign launched by a video by a man named @PetrLudwig. Soon the whole country was clamouring to wear masks. 5/
Slovakia soon followed on March 24, https://spectator.sme.sk/c/22366501/masks-will-be-obligatory-new-measures-mainly-aimed-at-the-elderly.html, and Austria on March 30th. https://ft.com/content/f68f3063-5024-4654-9389-bcc7ee1efd8e 6/
This allows for an incredible experiment in public health policy impacts, that can be followed by anyone at home. We actually have pretty good data on country wide deaths. My preferred site to follow this data, with daily breakdowns, is https://worldometers.info/coronavirus/ . 7/
(why follow deaths and not new cases? the data for new cases is much less reliable, it is impacted by testing rates, testing criteria, and number of asymptomatic cases in the country. Much harder, but not impossible, to misinterpret mortality stats) 8/
It takes about 23 days for the impact of a policy change to flow through to mortality. An average of 5 days for the newly infected person to show symptoms, and another 18 days to death. https://thelancet.com/journals/lancet/article/PIIS0140-6736(20)30566-3/fulltext 9/
So, the impact of Czechia's policy will start to be seen in 4 days, April 11. 23 days after Mar 19. https://worldometers.info/coronavirus/country/czech-republic/ Will the mortality curve flatten here over the next few days? That will be key. Times are average so we may start to see the impact a little earlier. 10/
Slovakia's mask impact date? Apr 16. Austria's? Apr 22. And we can follow this in real time, on our desktop. (Slovakia only has two reported deaths so far, so not much to watch there) 11/
Worth noting that the case rate of Germany has started to fall recently (but not the mortality rate). So obviously other factors at play. Poland continues to have rising case rates and mortality. We'll need to look at the differences between them all. 12/
But patterns will hopefully become obvious. And then we'll have a better idea if universal masking has an impact on coronavirus transmission, at a population level. And you can, in a rough sense, do some public health science from your armchair. /fin.
Inspired by this paper by Christopher Leffer and
@EdselIng https://www.researchgate.net/publication/340438732_Country-wide_Mortality_from_the_Novel_Coronavirus_COVID-19_Pandemic_and_Notes_Regarding_Mask_Usage_by_the_Public?channel=doi&linkId=5e88f28f92851c2f527f7499&showFulltext=true&fbclid=IwAR3E-KR-6VZ5JBLPiLqngvO0GyWzalLWv58pzADowegR5Ry5SgP1vA986AY
@EdselIng https://www.researchgate.net/publication/340438732_Country-wide_Mortality_from_the_Novel_Coronavirus_COVID-19_Pandemic_and_Notes_Regarding_Mask_Usage_by_the_Public?channel=doi&linkId=5e88f28f92851c2f527f7499&showFulltext=true&fbclid=IwAR3E-KR-6VZ5JBLPiLqngvO0GyWzalLWv58pzADowegR5Ry5SgP1vA986AY