In medicine as elsewhere in life, if you ask the wrong question, you’re likely to get the wrong answer. So if the question is, “Do masks worn outside medical settings work to protect against COVID-19 and respiratory diseases?” — or its politically charged companion, “Do you believe in masks?” — don’t be surprised if the answers you receive are simplistic or wrong.
A perfect example was the recent publication of an analysis by the respected Cochrane Library, an organization that collates and reports the results of scientific studies. It examined a series of randomized controlled trials published in the scientific literature that asked whether surgical masks, N95 masks or P2 respirators prevented the transmission of respiratory viruses. The overarching consensus was that wearing a mask in ordinary public places “probably makes little or no difference” in an individual’s risk of acquiring influenza or COVID-19.
The response by the news media and scientific community was predictable. Masking skeptics pounced, interpreting this to mean that masks are worthless, thus ignoring the words “probably” and “little or no difference” that leave open the possibility of benefit at the margins or in high-risk settings, which can exert a dramatic effect in a large population. Meanwhile, masking defenders mounted a vigorous takedown of the report and an impassioned defense of masks as essential.
