Opinion – Covid-19: controversial trial may actually show that masks protect the wearer

Covid-19: controversial trial may actually show that masks protect the wearer – The BMJ Opinion

Original study and commentaries: Randomized trial suggesting mask use does not protect the wearer from Covid-19 sparks controversy

Related commentary on Twitter (thread – click for more)

1/
My appraisal of the Danish mask study (DANMASK-19): This was a negative trial – masks were not shown to prevent #COVID19.

Could chance or bias make this outcome more likely?
Does this mean we don’t need to wear masks?

Let’s take a deeper look.#HowIReadThisPaper

(Thread) pic.twitter.com/bAUuajgtaI

— Rahul Ganatra (@rbganatra) November 28, 2020