STAT reports:

Back in April, President Trump picked out a single computer model of coronavirus spread as his oracle of choice. Unsurprisingly, that simulation initially had rosier estimates than other algorithms, projecting many fewer Covid-19 deaths — and its unconventional calculations and fluctuating estimates drew sharp criticism from epidemiologists.

But the statisticians behind it have since changed their methods, and their new numbers, published Friday, bolster what scientists have long been saying: That doing away with social distancing measures could entail vast numbers of deaths, and that widespread mask-wearing in public could save tens of thousands of lives.

“We think the key point here is that there’s a huge winter surge coming,” Christopher Murray, a lead author on the paper and the director of the University of Washington’s Institute for Health Metrics and Evaluation, said in a press briefing. At this point, the wave isn’t fully preventable, but “expanding mask use is one of the easy wins for the United States.”

Specifically, the paper projected that there could be some half a million Covid-19-related deaths in the U.S. by the end of February, and that some 130,000 of those tragedies might be forestalled with universal mask use. But experts warn that the figures from any of the model’s hypothetical scenarios are less useful than the comparison between the different possibilities. By putting those projections side by side, you can start to see how much of an effect something like mask-wearing might have on a population level, if you take the authors’ estimation that face coverings can reduce an individual’s risk of infection by about 40%.

“The exact numbers are impossible to predict,” said Ruth Etzioni, a biostatistician at the Fred Hutchinson Cancer Research Center and the University of Washington, who was not involved in the new research. “What should drive policy here is the difference between the scenarios with and without masks.” [Continue reading…]