Do physical distancing, face masks & eye protection person-to-person transmission of COVID-19?

The preventives are just making sense and logical. Although there is no RCT (many risk of bias unavoidable) found and included in this SR & MA, the evidence grade is elevated when some effect sizes (aOR) are large (≤0.2), so they worth attention.

However, some CI are also relatively large indicating relative small sample size in those subgrp analyses, and some risk differences are small suggesting there are other important factors (confounding) influencing the (causal) relations between the preventive measures and outcome.

https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)31142-9/fulltext