evidence: People online are touting the results of a Cochrane review to incorrectly claim that it shows masks "don’t work" against the coronavirus. But the primary conclusion of the review is that it’s uncertain from randomized controlled trials whether mask interventions in the community help slow the spread of respiratory illnesses. [...] In other words, there isn’t good evidence from randomized controlled trials that encouraging mask use in the community prevents the spread of respiratory diseases, but the issue also hasn’t been studied very well. So the real answer is unknown. [...] "It would be accurate to say that the review examined whether interventions to promote mask wearing help to slow the spread of respiratory viruses, and that the results were inconclusive," she continued. "Given the limitations in the primary evidence, the review is not able to address the question of whether mask-wearing itself reduces people’s risk of contracting or spreading respiratory viruses."