> That study showed that the effect of surgical masks was statistically significant when used by the elderly 50+ population. For other age groups and for cloth masks, the advantage was statistically insignificant.
The study could prove that the masks worked in 50+. And this was with a maximum of 40% of people complying.
This does NOT mean that the masks didn't work in 50-. It means that the statistical power was insufficient to prove that they worked.
It could also mean that 50- didn't comply with masks as well. It could also mean that 50- engaged in other risky behavior. etc.
Why everybody seems to think that "Provably works in 50+" and "Provably doesn't work in 50-" are completely compatible ideas is completely beyond me. "Provably works in 50+" significantly increases the Bayesian prior on "Works in 50- even if we can't prove such."
The advantage of this study is that the villages were randomized so it's unlikely that the control group engaged in more risky behavior than the treatment group.
This result for 50+ was right on the edge of the significance interval so proves is probably too strong of a word. It means you would expect this result to happen by chance if the experiment were repeated 20 times. It is definitely evidence for some efficacy but it is about as weak as it gets to be considered evidence from a scientific POV.
My point was just that the headlines painted a significantly different picture than was contained within the paper itself.
The study could prove that the masks worked in 50+. And this was with a maximum of 40% of people complying.
This does NOT mean that the masks didn't work in 50-. It means that the statistical power was insufficient to prove that they worked.
It could also mean that 50- didn't comply with masks as well. It could also mean that 50- engaged in other risky behavior. etc.
Why everybody seems to think that "Provably works in 50+" and "Provably doesn't work in 50-" are completely compatible ideas is completely beyond me. "Provably works in 50+" significantly increases the Bayesian prior on "Works in 50- even if we can't prove such."