Face coverings seem to have done little to mitigate the spread of COVId. Scotland has the highest case numbers in the world despite mask discipline. This combined with the lack of any conclusive testing as to their effectiveness would suggest face coverings are pointless other than as a psychological tool to make people feel better.
That study is an evidence based review. It is not based on double blind testing and includes the extrapolation of the results of influenza studies. My comment referred to conclusive testing.
Face coverings seem to have done little to mitigate the spread of COVId. Scotland has the highest case numbers in the world despite mask discipline. This combined with the lack of any conclusive testing as to their effectiveness would suggest face coverings are pointless other than as a psychological tool to make people feel better.