Covid-19 down in 24 counties with mask mandates, up in 81 counties without

Treat this article with the same skepticism you would as if the article said "Covid-19 lower in counties without mask mandates." This is true according to the data, by the way.

That being said, wear masks. Be upset with major world health organizations for not recommending mask usage earlier than they did. Treat anything anyone says about Covid, including this very post, with caution and skepticism. There's always an agenda and there's always bias.

Covid is down/non-existent in counties in Western Kansas too where nobody is wearing masks.

These "studies" are worthless because they contain so many lurking variables. They do more harm than good because they distort reality and "cry wolf", weakening the public response when compliance is needed elsewhere.

I'm not saying don't wear a mask. The best studies we have so seem to suppport they slow disease transmission. But we shouldn't let bad science get a free pass.

If you are wondering why the analysis ends on August 23:

> August 23, 2020, was selected as the study end date because most Kansas counties had already started or were about to begin school the week of August 24, 2020. The implementation of in-person schooling would have signified an important change in events influencing COVID-19 incidence rates after the executive order.

I suspect there’s a bit more to this one. My immediate question was “do these populations differ?” because you could imagine some confounding effect where counties which rejected mask-wearing have something else in common, like say not following other best practices.

Skimming the paper (https://www.cdc.gov/mmwr/volumes/69/wr/pdfs/mm6947e2-H.pdf), check out the chart on page 4; seems like when you look at the trend lines, the counties that didn’t enact mask restrictions had a lower rate of increase in infections prior to those restrictions going into effect, and the rate of increase didn’t change after. Furthermore, there was a really big spike around the time that the restrictions were put in place in the counties that enacted mandates. That spike didn’t show up in the counties where restrictions were not put in place.

I’m not sure to what extent regression to the mean applies in the context of infectious diseases; you could imagine some effects like holiday week where folks increase their risk for a short time and then stop again, causing the infection rate to drop again. I wrote that before checking the dates, and indeed the spike was around 4th July, so there’s a fairly good reason to believe that at least some of the reported post-intervention drop in infection rate was just due to people reducing their mixing/socializing back to pre-holiday levels. Though the rate started increasing before Jul4 so this can’t be the full explanation.

I support wearing masks, but this particular study doesn’t seem like strong evidence.

This seems to be very good evidence that mask mandates work. And not just masks, which for some reason people still dispute, but also for mandating mask usage when necessary.

I have seen some argue that mandating doesn't work or even makes things worse, but this data seems to indicate otherwise.

Conclusion: Officials in counties more likely to experience a Covd19 increase due to the political attitudes of their constituents, were under higher pressure to not mandate masks.

Oh I'm sorry, did i just ruin your beautiful correlation that you thought was causal?

I'm still more concerned with death or permanent injury rates then transmission rates. Have we moved the needle in those regards?