Podcast 617: Masks and Understanding Data

<p><strong>Contributor: Peter Bakes, MD</strong></p> <p><strong>Educational Pearls:</strong></p> <ul> <li style="font-weight: 400;"><span style= "font-weight: 400;">Recent study looked at if mask wearing protects the mask wearer from infection</span></li> <li style="font-weight: 400;"><span style="font-weight: 400;">This group found 1.8% of mask wearers got COVID while 2.1% of non-mask wearers became infected, which was not statistically significant</span></li> <li style="font-weight: 400;"><span style="font-weight: 400;">This was not statistically significant and has been used to justify not wearing masks by some groups</span></li> <li style="font-weight: 400;"><span style="font-weight: 400;">While the numbers look small, it's close to a 20% reduction in infections for the mask wearers</span></li> <li style="font-weight: 400;"><span style="font-weight: 400;">The results reported had concerns for being underpowered, meaning the studies population may not be big enough to draw definitive conclusions</span></li> <li style="font-weight: 400;"><span style="font-weight: 400;">Many limitations of study including how wearing a mask may protect others</span></li> <li style="font-weight: 400;"><span style= "font-weight: 400;">Unfortunately, studies like these can lead to misinterpretation and distortion</span></li> </ul> <p><strong>References</strong></p> <p><span style="font-size: 10pt;"><span style= "font-weight: 400;">Bundgaard H, Bundgaard JS, Raaschou-Pedersen DET, von Buchwald C, Todsen T, Norsk JB, Pries-Heje MM, Vissing CR, Nielsen PB, Winsløw UC, Fogh K, Hasselbalch R, Kristensen JH, Ringgaard A, Porsborg Andersen M, Goecke NB, Trebbien R, Skovgaard K, Benfield T, Ullum H, Torp-Pedersen C, Iversen K.</span> <a href= "https://pubmed.ncbi.nlm.nih.gov/33205991/"><span style= "font-weight: 400;">Effectiveness of Adding a Mask Recommendation to Other Public Health Measures to Prevent SARS-CoV-2 Infection in Danish Mask Wearers : A Randomized Controlled Trial.</span></a> <span style="font-weight: 400;">Ann Intern Med.