London, Jan. 20 -- Mask-wearing is associated with better control of COVID-19 transmission in the community, according to a study that links data from a survey of more than 300,000 people in the US with localised estimates of virus transmission based on the reproductive number (R), published today in The Lancet Digital Health journal.

The study, based on observational data and mathematical modelling, found that a 10% increase in self-reported mask-wearing was associated with a more than 3-fold better odds of keeping the instantaneous reproductive number (Rt), which measures the number of secondary cases arising from a single case for a given time point, below 1.

An Rt number below 1 is considered a key sign that virus transmission is sl...